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Manohar A, Yang J, Pack JD, Ho G, McVeigh ER. Motion correction of wide-detector 4DCT images for cardiac resynchronization therapy planning. J Cardiovasc Comput Tomogr 2024; 18:170-178. [PMID: 38242778 PMCID: PMC11087942 DOI: 10.1016/j.jcct.2024.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/11/2023] [Accepted: 01/07/2024] [Indexed: 01/21/2024]
Abstract
BACKGROUND Lead placement at the latest mechanically activated left ventricle (LV) segments is strongly correlated with response to cardiac resynchronization therapy (CRT). We demonstrate the feasibility of a cardiac 4DCT motion correction algorithm (ResyncCT) in estimating LV mechanical activation for guiding lead placement in CRT. METHODS Subjects with full cardiac cycle 4DCT images acquired using a wide-detector CT scanner for CRT planning/upgrade were included. 4DCT images exhibited motion artifact-induced false-dyssynchrony, hindering LV mechanical activation time estimation. Motion-corrupted images were processed with ResyncCT to yield motion-corrected images. Time to onset of shortening (TOS) was estimated in each of 72 endocardial segments. A false-dyssynchrony index (FDI) was used to quantify the extent of motion artifacts in the uncorrected and the ResyncCT images. After motion correction, the change in classification of LV free-wall segments as optimal target sites for lead placement was investigated. RESULTS Twenty subjects (70.7 ± 13.9 years, 6 female) were analyzed. Motion artifacts in the ResyncCT-processed images were significantly reduced (FDI: 28.9 ± 9.3 % vs 47.0 ± 6.0 %, p < 0.001). In 10 (50 %) subjects, ResyncCT motion correction yielded statistically different TOS estimates (p < 0.05). Additionally, 43 % of LV free-wall segments were reclassified as optimal target sites for lead placement after motion correction. CONCLUSIONS ResyncCT significantly reduced motion artifacts in wide-detector cardiac 4DCT images, yielded statistically different time to onset of shortening estimates, and changed the location of optimal target sites for lead placement. These results highlight the potential utility of ResyncCT motion correction in CRT planning when using wide-detector 4DCT imaging.
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Affiliation(s)
- Ashish Manohar
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA, USA; Department of Radiology, Stanford University, Stanford, CA, USA; Cardiovascular Institute, Stanford University, Stanford, CA, USA
| | - James Yang
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Jed D Pack
- Radiation Systems Lab, GE Global Research, Niskayuna, New York, USA
| | - Gordon Ho
- Department of Medicine, Division of Cardiology, University of California San Diego, La Jolla, CA, USA
| | - Elliot R McVeigh
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA; Department of Medicine, Division of Cardiology, University of California San Diego, La Jolla, CA, USA; Department of Radiology, University of California San Diego, La Jolla, CA, USA.
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Soozande M, Ossenkoppele BW, Hopf Y, Pertijs MAP, Verweij MD, de Jong N, Vos HJ, Bosch JG. Imaging Scheme for 3-D High-Frame-Rate Intracardiac Echography: A Simulation Study. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:2862-2874. [PMID: 35759589 DOI: 10.1109/tuffc.2022.3186487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia and is normally treated by RF ablation. Intracardiac echography (ICE) is widely employed during RF ablation procedures to guide the electrophysiologist in navigating the ablation catheter, although only 2-D probes are currently clinically used. A 3-D ICE catheter would not only improve visualization of the atrium and ablation catheter, but it might also provide the 3-D mapping of the electromechanical wave (EW) propagation pattern, which represents the mechanical response of cardiac tissue to electrical activity. The detection of this EW needs 3-D high-frame-rate imaging, which is generally only realizable in tradeoff with channel count and image quality. In this simulation-based study, we propose a high volume rate imaging scheme for a 3-D ICE probe design that employs 1-D micro-beamforming in the elevation direction. Such a probe can achieve a high frame rate while reducing the channel count sufficiently for realization in a 10-Fr catheter. To suppress the grating-lobe (GL) artifacts associated with micro-beamforming in the elevation direction, a limited number of fan-shaped beams with a wide azimuthal and narrow elevational opening angle are sequentially steered to insonify slices of the region of interest. An angular weighted averaging of reconstructed subvolumes further reduces the GL artifacts. We optimize the transmit beam divergence and central frequency based on the required image quality for EW imaging (EWI). Numerical simulation results show that a set of seven fan-shaped transmission beams can provide a frame rate of 1000 Hz and a sufficient spatial resolution to visualize the EW propagation on a large 3-D surface.
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Manohar A, Pack JD, Schluchter AJ, McVeigh ER. Four-dimensional computed tomography of the left ventricle, Part II: Estimation of mechanical activation times. Med Phys 2022; 49:2309-2323. [PMID: 35192200 PMCID: PMC9007845 DOI: 10.1002/mp.15550] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 01/27/2022] [Accepted: 02/13/2022] [Indexed: 11/11/2022] Open
Abstract
PURPOSE We demonstrate the viability of a four-dimensional X-ray computed tomography (4DCT) imaging system to accurately and precisely estimate mechanical activation times of left ventricular (LV) wall motion. Accurate and reproducible timing estimates of LV wall motion may be beneficial in the successful planning and management of cardiac resynchronization therapy (CRT). METHODS We developed an anthropomorphically accurate in silico LV phantom based on human CT images with programmed septal-lateral wall dyssynchrony. Twenty-six temporal phases of the in silico phantom were used to sample the cardiac cycle of 1 s. For each of the 26 phases, 1 cm thick axial slabs emulating axial CT image volumes were extracted, 3D printed, and imaged using a commercially available CT scanner. A continuous dynamic sinogram was synthesized by blending sinograms from these static phases; the synthesized sinogram emulated the sinogram that would be acquired under true continuous phantom motion. Using the synthesized dynamic sinogram, images were reconstructed at 70 ms intervals spanning the full cardiac cycle; these images exhibited expected motion artifact characteristics seen in images reconstructed from real dynamic data. The motion corrupted images were then processed with a novel motion correction algorithm (ResyncCT) to yield motion corrected images. Five pairs of motion uncorrected and motion corrected images were generated, each corresponding to a different starting gantry angle (0 to 180 degrees in 45 degree increments). Two line profiles perpendicular to the endocardial surface were used to sample local myocardial motion trajectories at the septum and the lateral wall. The mechanical activation time of wall motion was defined as the time at which the endocardial boundary crossed a fixed position defined on either of the two line profiles while moving toward the center of the LV during systolic contraction. The mechanical activation times of these myocardial trajectories estimated from the motion uncorrected and the motion corrected images were then compared with those derived from the static images of the 3D printed phantoms (ground truth). The precision of the timing estimates was obtained from the five different starting gantry angle simulations. RESULTS The range of estimated mechanical activation times observed across all starting gantry angles was significantly larger for the motion uncorrected images than for the motion corrected images (lateral wall: 58 ± 15 ms vs 12 ± 4 ms, p < 0.005; septal wall: 61 ± 13 ms vs 13 ± 9 ms, p < 0.005). CONCLUSIONS 4DCT images processed with the ResyncCT motion correction algorithm yield estimates of mechanical activation times of LV wall motion with significantly improved accuracy and precision. The promising results reported in this study highlight the potential utility of 4DCT in estimating the timing of mechanical events of interest for CRT guidance.
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Affiliation(s)
- Ashish Manohar
- Department of Mechanical and Aerospace Engineering, UC San Diego School of Engineering, La Jolla, California, USA
| | - Jed D Pack
- Radiation Systems Lab, GE Global Research, Niskayuna, New York, USA
| | - Andrew J Schluchter
- Department of Bioengineering, UC San Diego School of Engineering, La Jolla, California, USA
| | - Elliot R McVeigh
- Department of Bioengineering, UC San Diego School of Engineering, La Jolla, California, USA
- Department of Radiology, University of California San Diego, La Jolla, California, USA
- Department of Medicine, Cardiovascular Division, UC San Diego School of Medicine, La Jolla, California, USA
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4
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Tang X, He Y, Liu J. Soft bioelectronics for cardiac interfaces. BIOPHYSICS REVIEWS 2022; 3:011301. [PMID: 38505226 PMCID: PMC10903430 DOI: 10.1063/5.0069516] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 12/10/2021] [Indexed: 03/21/2024]
Abstract
Bioelectronics for interrogation and intervention of cardiac systems is important for the study of cardiac health and disease. Interfacing cardiac systems by using conventional rigid bioelectronics is limited by the structural and mechanical disparities between rigid electronics and soft tissues as well as their limited performance. Recently, advances in soft electronics have led to the development of high-performance soft bioelectronics, which is flexible and stretchable, capable of interfacing with cardiac systems in ways not possible with conventional rigid bioelectronics. In this review, we first review the latest developments in building flexible and stretchable bioelectronics for the epicardial interface with the heart. Next, we introduce how stretchable bioelectronics can be integrated with cardiac catheters for a minimally invasive in vivo heart interface. Then, we highlight the recent progress in the design of soft bioelectronics as a new class of biomaterials for integration with different in vitro cardiac models. In particular, we highlight how these devices unlock opportunities to interrogate the cardiac activities in the cardiac patch and cardiac organoid models. Finally, we discuss future directions and opportunities using soft bioelectronics for the study of cardiac systems.
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Affiliation(s)
- Xin Tang
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, Massachusetts 02134, USA
| | - Yichun He
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, Massachusetts 02134, USA
| | - Jia Liu
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, Massachusetts 02134, USA
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5
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Colli Franzone P, Pavarino LF, Scacchi S. Numerical evaluation of cardiac mechanical markers as estimators of the electrical activation time. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2021; 37:e3285. [PMID: 31808301 DOI: 10.1002/cnm.3285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 10/11/2019] [Accepted: 11/10/2019] [Indexed: 06/10/2023]
Abstract
Recent advances in the development of noninvasive cardiac imaging technologies have made it possible to measure longitudinal and circumferential strains at a high spatial resolution also at intramural level. Local mechanical activation times derived from these strains can be used as noninvasive estimates of electrical activation, in order to determine, eg, the origin of premature ectopic beats during focal arrhythmias or the pathway of reentrant circuits. The aim of this work is to assess the reliability of mechanical activation time markers derived from longitudinal and circumferential strains, denoted by ATell and ATecc , respectively, by means of three-dimensional cardiac electromechanical simulations. These markers are compared against the electrical activation time (ATv ), computed from the action potential waveform, and the reference mechanical activation markers derived from the active tension and fiber strain waveforms, denoted by ATta and ATeff , respectively. Our numerical simulations are based on a strongly coupled electromechanical model, including bidomain representation of the cardiac tissue, mechanoelectric (ie, stretch-activated channels) and geometric feedbacks, transversely isotropic strain energy function for the description of passive mechanics and detailed membrane and excitation-contraction coupling models. The results have shown that, during endocardial and epicardial ectopic stimulations, all the mechanical markers considered are highly correlated with ATv , exhibiting correlation coefficients larger than 0.8. However, during multiple endocardial stimulations, mimicking the ventricular sinus rhythm, the mechanical markers are less correlated with the electrical activation time, because of the more complex resulting excitation sequence. Moreover, the inspection of the endocardial and epicardial isochrones has shown that the ATell and ATecc mechanical activation sequences reproduce only some qualitative features of the electrical activation sequence, such as the areas of early and late activation, but in some cases, they might yield wrong excitation sources and significantly different isochrones patterns.
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Affiliation(s)
| | - Luca F Pavarino
- Dipartimento di Matematica, Università di Milano, Milano, Italy
| | - Simone Scacchi
- Dipartimento di Matematica, Università di Milano, Milano, Italy
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6
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Han B, Trew ML, Zgierski-Johnston CM. Cardiac Conduction Velocity, Remodeling and Arrhythmogenesis. Cells 2021; 10:cells10112923. [PMID: 34831145 PMCID: PMC8616078 DOI: 10.3390/cells10112923] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/14/2021] [Accepted: 10/22/2021] [Indexed: 02/06/2023] Open
Abstract
Cardiac electrophysiological disorders, in particular arrhythmias, are a key cause of morbidity and mortality throughout the world. There are two basic requirements for arrhythmogenesis: an underlying substrate and a trigger. Altered conduction velocity (CV) provides a key substrate for arrhythmogenesis, with slowed CV increasing the probability of re-entrant arrhythmias by reducing the length scale over which re-entry can occur. In this review, we examine methods to measure cardiac CV in vivo and ex vivo, discuss underlying determinants of CV, and address how pathological variations alter CV, potentially increasing arrhythmogenic risk. Finally, we will highlight future directions both for methodologies to measure CV and for possible treatments to restore normal CV.
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Affiliation(s)
- Bo Han
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, 79110 Freiburg im Breisgau, Germany;
- Faculty of Medicine, University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, 79104 Freiburg im Breisgau, Germany
- Department of Cardiovascular Surgery, The Fourth People’s Hospital of Jinan, 250031 Jinan, China
| | - Mark L. Trew
- Auckland Bioengineering Institute, University of Auckland, Auckland 1010, New Zealand;
| | - Callum M. Zgierski-Johnston
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, 79110 Freiburg im Breisgau, Germany;
- Faculty of Medicine, University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Correspondence:
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Obara Y, Mori S, Arakawa M, Kanai H. Multifrequency Phased Tracking Method for Estimating Velocity in Heart Wall. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:1077-1088. [PMID: 33483160 DOI: 10.1016/j.ultrasmedbio.2020.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 12/01/2020] [Accepted: 12/12/2020] [Indexed: 06/12/2023]
Abstract
Local high-accuracy velocity estimation is important for the ultrasound-based evaluation of regional myocardial function. The ultrasound phase difference at the center frequency of the transmitted signal has been conventionally used for velocity estimation. In the conventional method, spatial averaging is necessary owing to the frequency-dependent attenuation and interference of backscattered waves. Here, we propose a method for suppressing these effects using multifrequency phase differences. The resulting improvement in velocity estimation in the heart wall was validated by in vivo experiments. In the conventional method, the velocity waveform exhibits spike-like changes. The velocity waveform estimated using the proposed method did not exhibit such changes. Because the proposed method estimates myocardium velocity without spatial averaging, it can be used for measuring heart wall dynamics involving thickness changes.
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Affiliation(s)
- Yu Obara
- Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan
| | - Shohei Mori
- Graduate School of Engineering, Tohoku University, Sendai, Japan.
| | - Mototaka Arakawa
- Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan; Graduate School of Engineering, Tohoku University, Sendai, Japan
| | - Hiroshi Kanai
- Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan; Graduate School of Engineering, Tohoku University, Sendai, Japan
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8
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Phung TKN, Waters CD, Holmes JW. Open-Source Routines for Building Personalized Left Ventricular Models From Cardiac Magnetic Resonance Imaging Data. J Biomech Eng 2020; 142:024504. [PMID: 31141592 PMCID: PMC7104752 DOI: 10.1115/1.4043876] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 05/20/2019] [Indexed: 11/08/2022]
Abstract
Creating patient-specific models of the heart is a promising approach for predicting outcomes in response to congenital malformations, injury, or disease, as well as an important tool for developing and customizing therapies. However, integrating multimodal imaging data to construct patient-specific models is a nontrivial task. Here, we propose an approach that employs a prolate spheroidal coordinate system to interpolate information from multiple imaging datasets and map those data onto a single geometric model of the left ventricle (LV). We demonstrate the mapping of the location and transmural extent of postinfarction scar segmented from late gadolinium enhancement (LGE) magnetic resonance imaging (MRI), as well as mechanical activation calculated from displacement encoding with stimulated echoes (DENSE) MRI. As a supplement to this paper, we provide MATLAB and Python versions of the routines employed here for download from SimTK.
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Affiliation(s)
- Thien-Khoi N. Phung
- Department of Biomedical Engineering, University of
Virginia, Charlottesville, VA 22908
| | - Christopher D. Waters
- Department of Biomedical Engineering, University of
Virginia, Charlottesville, VA 22908
| | - Jeffrey W. Holmes
- Department of Biomedical Engineering, University of
Virginia, Charlottesville, VA 22908;
Department of Medicine, University of Virginia,
Charlottesville, VA 22908; Robert M. Berne Cardiovascular
Center, University of Virginia, 415 Lane Road,
Charlottesville, VA 22908
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Naveed M, Mohammad IS, Xue L, Khan S, Gang W, Cao Y, Cheng Y, Cui X, DingDing C, Feng Y, Zhijie W, Xiaohui Z. The promising future of ventricular restraint therapy for the management of end-stage heart failure. Biomed Pharmacother 2018; 99:25-32. [PMID: 29324309 DOI: 10.1016/j.biopha.2018.01.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 12/19/2017] [Accepted: 01/03/2018] [Indexed: 01/31/2023] Open
Abstract
Complicated pathophysiological syndrome associated with irregular functioning of the heart leading to insufficient blood supply to the organs is linked to congestive heart failure (CHF) which is the leading cause of death in developed countries. Numerous factors can add to heart failure (HF) pathogenesis, including myocardial infarction (MI), genetic factors, coronary artery disease (CAD), ischemia or hypertension. Presently, most of the therapies against CHF cause modest symptom relief but incapable of giving significant recovery for long-term survival outcomes. Unfortunately, there is no effective treatment of HF except cardiac transplantation but genetic variations, tissue mismatch, differences in certain immune response and socioeconomic crisis are some major concern with cardiac transplantation, suggested an alternate bridge to transplant (BTT) or destination therapies (DT). Ventricular restraint therapy (VRT) is a promising, non-transplant surgical treatment wherein the overall goal is to wrap the dilated heart with prosthetic material to mechanically restrain the heart at end-diastole, stop extra remodeling, and thereby ultimately improve patient symptoms, ventricular function and survival. Ventricular restraint devices (VRDs) are developed to treat end-stage HF and BTT, including the CorCap cardiac support device (CSD) (CSD; Acorn Cardiovascular Inc, St Paul, Minn), Paracor HeartNet (Paracor Medical, Sunnyvale, Calif), QVR (Polyzen Inc, Apex, NC) and ASD (ASD, X. Zhou). An overview of 4 restraint devices, with their precise advantages and disadvantages, will be presented. The accessible peer-reviewed literature summarized with an important considerations on the mechanism of restraint therapy and how this acquaintance can be accustomed to optimize and improve its effectiveness.
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Affiliation(s)
- Muhammad Naveed
- Department of Clinical Pharmacy, School of Basic Medicine and Clinical Pharmacy China Pharmaceutical University, School of Pharmacy, Jiangsu Province, Nanjing 211198, PR China
| | - Imran Shair Mohammad
- Department of Pharmaceutics, China Pharmaceutical University, School of Pharmacy, Jiangsu Province, Nanjing 211198, PR China
| | - Li Xue
- Department of Clinical Pharmacy, School of Basic Medicine and Clinical Pharmacy China Pharmaceutical University, School of Pharmacy, Jiangsu Province, Nanjing 211198, PR China
| | - Sara Khan
- Department of Pharmaceutical Chemistry, University College of Pharmacy, University of the Punjab, Lahore 5400, Pakistan
| | - Wang Gang
- Department of Clinical Pharmacy, School of Basic Medicine and Clinical Pharmacy China Pharmaceutical University, School of Pharmacy, Jiangsu Province, Nanjing 211198, PR China
| | - Yanfang Cao
- Department of Clinical Pharmacy, School of Basic Medicine and Clinical Pharmacy China Pharmaceutical University, School of Pharmacy, Jiangsu Province, Nanjing 211198, PR China
| | - Yijie Cheng
- Department of Clinical Pharmacy, School of Basic Medicine and Clinical Pharmacy China Pharmaceutical University, School of Pharmacy, Jiangsu Province, Nanjing 211198, PR China
| | - Xingxing Cui
- Department of Clinical Pharmacy, School of Basic Medicine and Clinical Pharmacy China Pharmaceutical University, School of Pharmacy, Jiangsu Province, Nanjing 211198, PR China
| | - Chen DingDing
- Department of Clinical Pharmacy, School of Basic Medicine and Clinical Pharmacy China Pharmaceutical University, School of Pharmacy, Jiangsu Province, Nanjing 211198, PR China.
| | - Yu Feng
- Department of Clinical Pharmacy, School of Basic Medicine and Clinical Pharmacy China Pharmaceutical University, School of Pharmacy, Jiangsu Province, Nanjing 211198, PR China.
| | - Wang Zhijie
- Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, PR China.
| | - Zhou Xiaohui
- Department of Clinical Pharmacy, School of Basic Medicine and Clinical Pharmacy China Pharmaceutical University, School of Pharmacy, Jiangsu Province, Nanjing 211198, PR China; Department of Heart Surgery, Nanjing Shuiximen Hospital, Jiangsu Province, Nanjing 210017, PR China; Department of Cardiothoracic Surgery, Zhongda Hospital affiliated to Southeast University, Jiangsu Province, Nanjing 210017, PR China.
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Mafi-Rad M, van‘t Sant J, Blaauw Y, Doevendans PA, Cramer MJ, Crijns HJ, Prinzen FW, Meine M, Vernooy K. Regional Left Ventricular Electrical Activation and Peak Contraction Are Closely Related in Candidates for Cardiac Resynchronization Therapy. JACC Clin Electrophysiol 2017; 3:854-862. [DOI: 10.1016/j.jacep.2017.03.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 02/28/2017] [Accepted: 03/13/2017] [Indexed: 11/28/2022]
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11
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Exo-organoplasty interventions: A brief review of past, present and future directions for advance heart failure management. Biomed Pharmacother 2017; 88:162-172. [PMID: 28103510 DOI: 10.1016/j.biopha.2017.01.048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 01/07/2017] [Accepted: 01/09/2017] [Indexed: 12/11/2022] Open
Abstract
Heart failure (HF) is a debilitating disease in which abnormal function of the heart leads to imbalance of blood demand to tissues and organs. The pathogenesis of HF is very complex and various factors can contribute including myocardial infarction, ischemia, hypertension and genetic cardiomyopathies. HF is the leading cause of death and its prevalence is expected to increase in parallel with the population age. Different kind of therapeutic approaches including lifestyle modification, medication and pacemakers are used for HF patients in NYHA I-III functional class. However, for advance stage HF patient's (NYHA IV), ventricle assist devices are clinically use and stem cells are under active investigation. Most of these therapies leads to modest symptoms relief and have no significant role in long-term survival rate. Currently there is no effective treatment for advance HF except heart transplantation, which is still remain clinically insignificant because of donor pool limitation. As HF is a result of multiple etiologies therefore multi-functional therapeutic platform is needed. Exo-organoplasty interventions are studied from almost one century. The major goals of these interventions are to treat various kind of heart disease from outside the heart muscle without having direct contact with blood. Various kind of interventions (devices and techniques) are developed in this arena with the passage of time. The purpose of this review is to describe the theory behind intervention devices, the devices themselves, their clinical results, advantages and limitations. Furthermore, to present a future multi-functional therapeutic platform (ASD) for advance stage HF management.
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12
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Auger DA, Bilchick KC, Gonzalez JA, Cui SX, Holmes JW, Kramer CM, Salerno M, Epstein FH. Imaging left-ventricular mechanical activation in heart failure patients using cine DENSE MRI: Validation and implications for cardiac resynchronization therapy. J Magn Reson Imaging 2017; 46:887-896. [PMID: 28067978 DOI: 10.1002/jmri.25613] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 12/09/2016] [Accepted: 12/10/2016] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To image late mechanical activation and identify effective left-ventricular (LV) pacing sites for cardiac resynchronization therapy (CRT). There is variability in defining mechanical activation time, with some studies using the time to peak strain (TPS) and some using the time to the onset of circumferential shortening (TOS). We developed improved methods for imaging mechanical activation and evaluated them in heart failure (HF) patients undergoing CRT. MATERIALS AND METHODS We applied active contours to cine displacement encoding with stimulated echoes (DENSE) strain images to detect TOS. Six healthy volunteers underwent magnetic resonance imaging (MRI) at 1.5T, and 50 patients underwent pre-CRT MRI (strain, scar, volumes) and echocardiography, assessment of the electrical activation time (Q-LV) at the LV pacing site, and echocardiography assessment of LV reverse remodeling 6 months after CRT. TPS at the LV pacing site was also measured by DENSE. RESULTS The latest TOS was greater in HF patients vs. healthy subjects (112 ± 28 msec vs. 61 ± 7 msec, P < 0.01). The correlation between TOS and Q-LV was strong (r > 0.75; P < 0.001) and better than between TPS and Q-LV (r < 0.62; P ≥ 0.006). Twenty-three of 50 patients had the latest activating segment in a region other than the mid-ventricular lateral wall, the most common site for the CRT LV lead. Using a multivariable model, TOS/QRS was significantly associated with LV reverse remodeling even after adjustment for overall dyssynchrony and scar (P < 0.05), whereas TPS was not (P = 0.49). CONCLUSION Late activation by cine DENSE TOS analysis is associated with improved LV reverse remodeling with CRT and deserves further study as a tool to achieve optimal LV lead placement in CRT. LEVEL OF EVIDENCE 1 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:887-896.
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Affiliation(s)
- Daniel A Auger
- Department of Biomedical Engineering, University of Virginia Health System, Charlottesville, Virginia, USA
| | - Kenneth C Bilchick
- Medicine/Cardiology/Electrophysiology, University of Virginia Health System, Charlottesville, Virginia, USA
| | - Jorge A Gonzalez
- Medicine/Cardiology/Electrophysiology, University of Virginia Health System, Charlottesville, Virginia, USA
| | - Sophia X Cui
- Department of Biomedical Engineering, University of Virginia Health System, Charlottesville, Virginia, USA
| | - Jeffrey W Holmes
- Department of Biomedical Engineering, University of Virginia Health System, Charlottesville, Virginia, USA.,Medicine/Cardiology/Electrophysiology, University of Virginia Health System, Charlottesville, Virginia, USA
| | - Christopher M Kramer
- Medicine/Cardiology/Electrophysiology, University of Virginia Health System, Charlottesville, Virginia, USA.,Radiology/Medical Imaging, University of Virginia Health System, Charlottesville, Virginia, USA
| | - Michael Salerno
- Department of Biomedical Engineering, University of Virginia Health System, Charlottesville, Virginia, USA.,Medicine/Cardiology/Electrophysiology, University of Virginia Health System, Charlottesville, Virginia, USA
| | - Frederick H Epstein
- Department of Biomedical Engineering, University of Virginia Health System, Charlottesville, Virginia, USA.,Radiology/Medical Imaging, University of Virginia Health System, Charlottesville, Virginia, USA
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13
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Costet A, Wan E, Bunting E, Grondin J, Garan H, Konofagou E. Electromechanical wave imaging (EWI) validation in all four cardiac chambers with 3D electroanatomic mapping in canines in vivo. Phys Med Biol 2016; 61:8105-8119. [PMID: 27782003 DOI: 10.1088/0031-9155/61/22/8105] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Characterization and mapping of arrhythmias is currently performed through invasive insertion and manipulation of cardiac catheters. Electromechanical wave imaging (EWI) is a non-invasive ultrasound-based imaging technique, which tracks the electromechanical activation that immediately follows electrical activation. Electrical and electromechanical activations were previously found to be linearly correlated in the left ventricle, but the relationship has not yet been investigated in the three other chambers of the heart. The objective of this study was to investigate the relationship between electrical and electromechanical activations and validate EWI in all four chambers of the heart with conventional 3D electroanatomical mapping. Six (n = 6) normal adult canines were used in this study. The electrical activation sequence was mapped in all four chambers of the heart, both endocardially and epicardially using the St Jude's EnSite 3D mapping system (St. Jude Medical, Secaucus, NJ). EWI acquisitions were performed in all four chambers during normal sinus rhythm, and during pacing in the left ventricle. Isochrones of the electromechanical activation were generated from standard echocardiographic imaging views. Electrical and electromechanical activation maps were co-registered and compared, and electrical and electromechanical activation times were plotted against each other and linear regression was performed for each pair of activation maps. Electromechanical and electrical activations were found to be directly correlated with slopes of the correlation ranging from 0.77 to 1.83, electromechanical delays between 9 and 58 ms and R 2 values from 0.71 to 0.92. The linear correlation between electrical and electromechanical activations and the agreement between the activation maps indicate that the electromechanical activation follows the pattern of propagation of the electrical activation. This suggests that EWI may be used as a novel non-invasive method to accurately characterize and localize sources of arrhythmias.
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Affiliation(s)
- Alexandre Costet
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
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14
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Grondin J, Costet A, Bunting E, Gambhir A, Garan H, Wan E, Konofagou EE. Validation of electromechanical wave imaging in a canine model during pacing and sinus rhythm. Heart Rhythm 2016; 13:2221-2227. [PMID: 27498277 DOI: 10.1016/j.hrthm.2016.08.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Indexed: 10/21/2022]
Abstract
BACKGROUND Accurate determination of regional areas of arrhythmic triggers is of key interest to diagnose arrhythmias and optimize their treatment. Electromechanical wave imaging (EWI) is an ultrasound technique that can image the transient deformation in the myocardium after electrical activation and therefore has the potential to detect and characterize location of triggers of arrhythmias. OBJECTIVES The objectives of this study were to investigate the relationship between the electromechanical and the electrical activation of the left ventricular (LV) endocardial surface during epicardial and endocardial pacing and during sinus rhythm as well as to map the distribution of electromechanical delays. METHODS In this study, 6 canines were investigated. Two external electrodes were sutured onto the epicardial surface of the LV. A 64-electrode basket catheter was inserted through the apex of the LV. Ultrasound channel data were acquired at 2000 frames/s during epicardial and endocardial pacing and during sinus rhythm. Electromechanical and electrical activation maps were synchronously obtained from the ultrasound data and the basket catheter, respectively. RESULTS The mean correlation coefficient between electromechanical and electrical activation was 0.81 for epicardial anterior pacing, 0.79 for epicardial lateral pacing, 0.69 for endocardial pacing, and 0.56 for sinus rhythm. CONCLUSION The electromechanical activation sequence determined by EWI follows the electrical activation sequence and more specifically in the case of pacing. This finding is of key interest in the role that EWI can play in the detection of the anatomical source of arrhythmias and the planning of pacing therapies such as cardiovascular resynchronization therapy.
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Affiliation(s)
| | | | | | - Alok Gambhir
- Department of Medicine, College of Physicians and Surgeons
| | - Hasan Garan
- Department of Medicine, College of Physicians and Surgeons
| | - Elaine Wan
- Department of Medicine, College of Physicians and Surgeons
| | - Elisa E Konofagou
- Department of Biomedical Engineering; Department of Radiology, Columbia University, New York, New York.
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15
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Gloschat CR, Koppel AC, Aras KK, Brennan JA, Holzem KM, Efimov IR. Arrhythmogenic and metabolic remodelling of failing human heart. J Physiol 2016; 594:3963-80. [PMID: 27019074 DOI: 10.1113/jp271992] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 03/21/2016] [Indexed: 12/24/2022] Open
Abstract
Heart failure (HF) is a major cause of morbidity and mortality worldwide. The global burden of HF continues to rise, with prevalence rates estimated at 1-2% and incidence approaching 5-10 per 1000 persons annually. The complex pathophysiology of HF impacts virtually all aspects of normal cardiac function - from structure and mechanics to metabolism and electrophysiology - leading to impaired mechanical contraction and sudden cardiac death. Pharmacotherapy and device therapy are the primary methods of treating HF, but neither is able to stop or reverse disease progression. Thus, there is an acute need to translate basic research into improved HF therapy. Animal model investigations are a critical component of HF research. However, the translation from cellular and animal models to the bedside is hampered by significant differences between species and among physiological scales. Our studies over the last 8 years show that hypotheses generated in animal models need to be validated in human in vitro models. Importantly, however, human heart investigations can establish translational platforms for safety and efficacy studies before embarking on costly and risky clinical trials. This review summarizes recent developments in human HF investigations of electrophysiology remodelling, metabolic remodelling, and β-adrenergic remodelling and discusses promising new technologies for HF research.
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Affiliation(s)
- C R Gloschat
- Department of Biomedical Engineering, The George Washington University, Washington, DC, USA
| | - A C Koppel
- Department of Biomedical Engineering, The George Washington University, Washington, DC, USA
| | - K K Aras
- Department of Biomedical Engineering, The George Washington University, Washington, DC, USA
| | - J A Brennan
- Department of Biomedical Engineering, The George Washington University, Washington, DC, USA
| | - K M Holzem
- Department of Biomedical Engineering, The George Washington University, Washington, DC, USA
| | - I R Efimov
- Department of Biomedical Engineering, The George Washington University, Washington, DC, USA
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16
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Technical advances in studying cardiac electrophysiology - Role of rabbit models. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 121:97-109. [PMID: 27210306 DOI: 10.1016/j.pbiomolbio.2016.05.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 05/01/2016] [Indexed: 12/15/2022]
Abstract
Cardiovascular research has made a major contribution to an unprecedented 10 year increase in life expectancy during the last 50 years: most of this increase due to a decline in mortality from heart disease and stroke. The majority of the basic cardiovascular science discoveries, which have led to this impressive extension of human life, came from investigations conducted in various small and large animal models, ranging from mouse to pig. The small animal models are currently popular because they are amenable to genetic engineering and are relatively inexpensive. The large animal models are favored at the translational stage of the investigation, as they are anatomically and physiologically more proximal to humans, and can be implanted with various devices; however, they are expensive and less amenable to genetic manipulations. With the advent of CRISPR genetic engineering technology and the advances in implantable bioelectronics, the large animal models will continue to advance. The rabbit model is particularly poised to become one of the most popular among the animal models that recapitulate human heart diseases. Here we review an array of the rabbit models of atrial and ventricular arrhythmias, as well as a range of the imaging and device technologies enabling these investigations.
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17
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Su Y, Liu Z, Xu L. An Universal and Easy-to-Use Model for the Pressure of Arbitrary-Shape 3D Multifunctional Integumentary Cardiac Membranes. Adv Healthc Mater 2016; 5:889-92. [PMID: 26891347 DOI: 10.1002/adhm.201501029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 01/04/2016] [Indexed: 11/08/2022]
Abstract
Recently developed concepts for 3D, organ-mounted electronics for cardiac applications require a universal and easy-to-use mechanical model to calculate the average pressure associated with operation of the device, which is crucial for evaluation of design efficacy and optimization. This work proposes a simple, accurate, easy-to-use, and universal model to quantify the average pressure for arbitrary-shape organs.
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Affiliation(s)
- Yewang Su
- State Key Laboratory of Nonlinear Mechanics; Institute of Mechanics; Chinese Academy of Sciences; Beijing 100190 China
- Department of Civil and Environmental Engineering; Northwestern University; Evanston IL 60208 USA
| | - Zhuangjian Liu
- Institute of High Performance Computing; A*Star; 138632 Singapore
| | - Lizhi Xu
- Department of Chemical Engineering and Department of Materials Science and Engineering; University of Michigan; Ann Arbor MI 48109 USA
- Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory; University of Illinois at Urbana-Champaign; Urbana IL 61801 USA
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18
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Kroon W, Lumens J, Potse M, Suerder D, Klersy C, Regoli F, Murzilli R, Moccetti T, Delhaas T, Krause R, Prinzen FW, Auricchio A. In vivo electromechanical assessment of heart failure patients with prolonged QRS duration. Heart Rhythm 2015; 12:1259-67. [DOI: 10.1016/j.hrthm.2015.03.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Indexed: 11/15/2022]
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19
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Kim J, Lee M, Rhim JS, Wang P, Lu N, Kim DH. Next-generation flexible neural and cardiac electrode arrays. Biomed Eng Lett 2014. [DOI: 10.1007/s13534-014-0132-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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20
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Xu L, Gutbrod SR, Bonifas AP, Su Y, Sulkin MS, Lu N, Chung HJ, Jang KI, Liu Z, Ying M, Lu C, Webb RC, Kim JS, Laughner JI, Cheng H, Liu Y, Ameen A, Jeong JW, Kim GT, Huang Y, Efimov IR, Rogers JA. 3D multifunctional integumentary membranes for spatiotemporal cardiac measurements and stimulation across the entire epicardium. Nat Commun 2014; 5:3329. [PMID: 24569383 DOI: 10.1038/ncomms4329] [Citation(s) in RCA: 290] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Accepted: 01/27/2014] [Indexed: 01/07/2023] Open
Abstract
Means for high-density multiparametric physiological mapping and stimulation are critically important in both basic and clinical cardiology. Current conformal electronic systems are essentially 2D sheets, which cannot cover the full epicardial surface or maintain reliable contact for chronic use without sutures or adhesives. Here we create 3D elastic membranes shaped precisely to match the epicardium of the heart via the use of 3D printing, as a platform for deformable arrays of multifunctional sensors, electronic and optoelectronic components. Such integumentary devices completely envelop the heart, in a form-fitting manner, and possess inherent elasticity, providing a mechanically stable biotic/abiotic interface during normal cardiac cycles. Component examples range from actuators for electrical, thermal and optical stimulation, to sensors for pH, temperature and mechanical strain. The semiconductor materials include silicon, gallium arsenide and gallium nitride, co-integrated with metals, metal oxides and polymers, to provide these and other operational capabilities. Ex vivo physiological experiments demonstrate various functions and methodological possibilities for cardiac research and therapy.
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Affiliation(s)
- Lizhi Xu
- 1] Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA [2]
| | - Sarah R Gutbrod
- 1] Department of Biomedical Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, USA [2]
| | - Andrew P Bonifas
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Yewang Su
- 1] Department of Civil and Environmental Engineering, Department of Mechanical Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA [2] Center for Mechanics and Materials, Tsinghua University, Beijing 100084, China
| | - Matthew S Sulkin
- Department of Biomedical Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, USA
| | - Nanshu Lu
- Department of Aerospace Engineering and Engineering Mechanics, University of Texas at Austin, Austin, Texas 78712, USA
| | - Hyun-Joong Chung
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2V4
| | - Kyung-In Jang
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Zhuangjian Liu
- Institute of High Performance Computing, Agency for Science, Technology and Research, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632, Singapore
| | - Ming Ying
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Chi Lu
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - R Chad Webb
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Jong-Seon Kim
- 1] Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA [2] Department of Chemical and Biomolecular Engineering (BK21 Program), Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
| | - Jacob I Laughner
- Department of Biomedical Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, USA
| | - Huanyu Cheng
- Department of Civil and Environmental Engineering, Department of Mechanical Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA
| | - Yuhao Liu
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Abid Ameen
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Jae-Woong Jeong
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Gwang-Tae Kim
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Yonggang Huang
- Department of Civil and Environmental Engineering, Department of Mechanical Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA
| | - Igor R Efimov
- Department of Biomedical Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, USA
| | - John A Rogers
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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21
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Simultaneous evaluation of wall motion and blood perfusion of a beating heart using stereoscopic fluorescence camera system. Comput Med Imaging Graph 2014; 38:276-84. [PMID: 24507764 DOI: 10.1016/j.compmedimag.2013.12.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Revised: 12/24/2013] [Accepted: 12/31/2013] [Indexed: 11/22/2022]
Abstract
In this study, we aimed to develop a stereoscopic fluorescence camera system for simultaneous evaluation of wall motion and tissue perfusion using indocyanine green (ICG) fluorescence imaging. The system consists of two high-speed stereo cameras, an excitation lamp, and a computer for image processing. Evaluation experiments demonstrated that the stereoscopic fluorescence camera system successfully performed the simultaneous measurement of wall motion and tissue perfusion based on ICG fluorescence imaging. Our system can be applied to intraoperative evaluation of cardiac status, leading to an improvement in surgical outcomes.
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22
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Costet A, Provost J, Gambhir A, Bobkov Y, Danilo P, Boink GJ, Rosen MR, Konofagou E. Electromechanical wave imaging of biologically and electrically paced canine hearts in vivo. ULTRASOUND IN MEDICINE & BIOLOGY 2014; 40:177-187. [PMID: 24239363 PMCID: PMC3897195 DOI: 10.1016/j.ultrasmedbio.2013.08.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 08/20/2013] [Accepted: 08/26/2013] [Indexed: 06/02/2023]
Abstract
Electromechanical wave imaging (EWI) has been show capable of directly and entirely non-invasively mapping the trans mural electromechanical activation in all four cardiac chambers in vivo. In this study, we assessed EWI repeatability and reproducibility, as well as its capability of localizing electronic and, for the first time, biological pacing locations in closed-chest, conscious canines. Electromechanical activation was obtained in six conscious animals during normal sinus rhythm (NSR) and idioventricular rhythms occurring in dogs with complete heart block instrumented with electronic and biologic pacemakers (EPM and BPM respectively). After atrioventricular node ablation, dogs were implanted with an EPM in the right ventricular (RV) endocardial apex (n = 4) and two additionally received a BPM at the left ventricular (LV) epicardial base (n = 2). EWI was performed trans thoracically during NSR, BPM and EPM pacing, in conscious dogs, using an unfocused transmit sequence at 2000 frames/s. During NSR, the EW originated at the right atrium (RA), propagated to the left atrium (LA) and emerged from multiple sources in both ventricles. During EPM, the EW originated at the RV apex and propagated throughout both ventricles. During BPM, the EW originated from the LV basal lateral wall and subsequently propagated throughout the ventricles. EWI differentiated BPM from EPM and NSR and identified the distinct pacing origins. Isochrone comparison indicated that EWI was repeatable and reliable. These findings thus indicate the potential for EWI to serve as a simple, non-invasive and direct imaging technology for mapping and characterizing arrhythmias as well as the treatments thereof.
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Affiliation(s)
- Alexandre Costet
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA
| | - Jean Provost
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA
| | - Alok Gambhir
- Department of Medicine-Cardiology, Columbia University, New York, NY, 10032, USA
| | - Yevgeniy Bobkov
- Department of Pharmacology, Columbia University, New York, NY, 10032, USA
| | - Peter Danilo
- Department of Pharmacology, Columbia University, New York, NY, 10032, USA
| | - Gerard J.J. Boink
- Department of Pharmacology, Columbia University, New York, NY, 10032, USA
- Interuniversity Cardiology Institute of the Netherlands (ICIN), Utrecht, the Netherlands
- Heart Failure Research Center, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Michael R. Rosen
- Department of Pharmacology, Columbia University, New York, NY, 10032, USA
| | - Elisa Konofagou
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA
- Department of Radiology, Columbia University, New York, NY, 10032, USA
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23
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Ando T, Kawashima D, Kim H, Joung S, Liao H, Kobayashi E, Gojo S, Kyo S, Ono M, Sakuma I. Direct minimally invasive intraoperative electrophysiological mapping of the heart. MINIM INVASIV THER 2013; 22:372-80. [PMID: 23992385 DOI: 10.3109/13645706.2013.831106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Cardiac electrophysiology aims to describe and treat the electrical activity of the heart. Although an epicardial approach is valuable in many surgical treatments such as coronary artery bypass grafting, maze ablation, and cell transplantation, very few techniques suited for minimally invasive surgery are available for measurement of epicardial electrophysiology. MATERIAL AND METHODS We developed a novel endoscopically-deployable expanding electrode array that can be applied for minimally invasive surgery. Our device consists of a flexible electrode array attached to arms which open and close the electrode sheet. Furthermore, we also developed a computer program to overlay an epicardial electrophysiological map on an endoscopic image. We performed both laboratory and in vivo experiments to examine the feasibility in clinical situations. RESULTS Evaluation experiments demonstrated that our novel mapping process that assumes spherical deformation of the electrode array enables us to overlay each electrode position with an accuracy of < 1 mm. Results of animal experiments using large animals (one dog and two pigs) demonstrated that our system enables construction of epicardial electrophysiological maps. CONCLUSION A novel endoscopically deployable expanding electrode array was developed. Evaluation experiments demonstrated that our device can be manipulated in simulated minimally invasive surgery, and enables construction of epicardial electrophysiological maps.
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Affiliation(s)
- Takehiro Ando
- Graduate School of Engineering, the University of Tokyo , Tokyo , Japan
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24
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Provost J, Gambhir A, Vest J, Garan H, Konofagou EE. A clinical feasibility study of atrial and ventricular electromechanical wave imaging. Heart Rhythm 2013; 10:856-62. [PMID: 23454060 DOI: 10.1016/j.hrthm.2013.02.028] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND Cardiac resynchronization therapy (CRT) and atrial ablation procedures currently lack a noninvasive imaging modality for reliable treatment planning and monitoring. Electromechanical wave imaging (EWI) is an ultrasound-based method that has previously been shown to be capable of noninvasively and transmurally mapping the activation sequence of the heart in animal studies by estimating and imaging the electromechanical wave, that is, the transient strains occurring in response to the electrical activation, at both high temporal and spatial resolutions. OBJECTIVE To demonstrate the feasibility of transthoracic EWI for mapping the activation sequence during different cardiac rhythms in humans. METHODS EWI was perfor`med in patients undergoing CRT and a left bundle branch block (LBBB) during sinus rhythm, left ventricular pacing, and right ventricular pacing, as well as in patients with atrial flutter (AFL) before intervention, EWI findings from patients with AFL were subsequently correlated with results from invasive intracardiac electrical mapping studies during intervention. In addition, the feasibility of single-heartbeat EWI at 2000 frames/s is demonstrated in humans for the first time in a patient with both AFL and right bundle branch block (RBBB). RESULTS The electromechanical activation maps demonstrated the capability of EWI to localize the pacing sites and characterize the bundle branch block activation sequence transmurally in patients with CRT. In patients with AFL, the EWI propagation patterns obtained with EWI were in excellent agreement with those obtained from invasive intracardiac mapping studies. CONCLUSIONS Our findings demonstrate the potential capability of EWI to aid in the assessment and follow-up of patients undergoing CRT pacing therapy and atrial ablation, with preliminary validation in vivo.
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Affiliation(s)
- Jean Provost
- Department of Biomedical Engineering, Columbia University, New York, New York 10027, USA
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25
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Electronic sensor and actuator webs for large-area complex geometry cardiac mapping and therapy. Proc Natl Acad Sci U S A 2012; 109:19910-5. [PMID: 23150574 DOI: 10.1073/pnas.1205923109] [Citation(s) in RCA: 193] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Curved surfaces, complex geometries, and time-dynamic deformations of the heart create challenges in establishing intimate, nonconstraining interfaces between cardiac structures and medical devices or surgical tools, particularly over large areas. We constructed large area designs for diagnostic and therapeutic stretchable sensor and actuator webs that conformally wrap the epicardium, establishing robust contact without sutures, mechanical fixtures, tapes, or surgical adhesives. These multifunctional web devices exploit open, mesh layouts and mount on thin, bio-resorbable sheets of silk to facilitate handling in a way that yields, after dissolution, exceptionally low mechanical moduli and thicknesses. In vivo studies in rabbit and pig animal models demonstrate the effectiveness of these device webs for measuring and spatially mapping temperature, electrophysiological signals, strain, and physical contact in sheet and balloon-based systems that also have the potential to deliver energy to perform localized tissue ablation.
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26
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Lumens J, Leenders GE, Cramer MJ, De Boeck BWL, Doevendans PA, Prinzen FW, Delhaas T. Mechanistic Evaluation of Echocardiographic Dyssynchrony Indices. Circ Cardiovasc Imaging 2012; 5:491-9. [DOI: 10.1161/circimaging.112.973446] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
The power of echocardiographic dyssynchrony indices to predict response to cardiac resynchronization therapy (CRT) appears to vary between indices and between studies. We investigated whether the variability of predictive power between the dyssynchrony indices can be explained by differences in their operational definitions.
Methods and Results—
In 132 CRT-candidates (left ventricular [LV] ejection fraction, 19 ± 6%; QRS width, 170 ± 22 ms), 4 mechanical dyssynchrony indices (septal systolic rebound stretch [SRSsept], interventricular mechanical dyssynchrony [IVMD], septal-to-lateral peak shortening delay [Strain-SL], and septal-to-posterior wall motion delay [SPWMD]) were quantified at baseline. CRT response was quantified as 6-month percent change of LV end-systolic volume. Multiscale computer simulations of cardiac mechanics and hemodynamics were used to assess the relationships between dyssynchrony indices and CRT response within wide ranges of dyssynchrony of LV activation and reduced contractility. In patients, SRSsept showed best correlation with CRT response followed by IVMD, Strain-SL, and SPWMD (
R
=−0.56, −0.50, −0.48, and −0.39, respectively; all
P
<0.01). In patients and simulations, SRSsept and IVMD showed a continuous linear relationship with CRT response, whereas Strain-SL and SPWMD showed discontinuous relationships characterized by data clusters. Model simulations revealed that this data clustering originated from the complex multipeak pattern of septal strain and motion. In patients and simulations with (simulated) LV scar, SRSsept and IVMD retained their linear relationship with CRT response, whereas Strain-SL and SPWMD did not.
Conclusions—
The power to predict CRT response differs between indices of mechanical dyssynchrony. SRSsept and IVMD better represent LV dyssynchrony amenable to CRT and better predict CRT response than the indices assessing time-to-peak deformation or motion.
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Affiliation(s)
- Joost Lumens
- From Maastricht University Medical Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands (J.L., F.W.P., T.D.); University Medical Center Utrecht, Utrecht, The Netherlands (G.E.L., M.J.C., P.A.D.); and Kantonsspital Luzern, Luzern, Switzerland (B.W.L.D.B.)
| | - Geert E. Leenders
- From Maastricht University Medical Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands (J.L., F.W.P., T.D.); University Medical Center Utrecht, Utrecht, The Netherlands (G.E.L., M.J.C., P.A.D.); and Kantonsspital Luzern, Luzern, Switzerland (B.W.L.D.B.)
| | - Maarten J. Cramer
- From Maastricht University Medical Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands (J.L., F.W.P., T.D.); University Medical Center Utrecht, Utrecht, The Netherlands (G.E.L., M.J.C., P.A.D.); and Kantonsspital Luzern, Luzern, Switzerland (B.W.L.D.B.)
| | - Bart W. L. De Boeck
- From Maastricht University Medical Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands (J.L., F.W.P., T.D.); University Medical Center Utrecht, Utrecht, The Netherlands (G.E.L., M.J.C., P.A.D.); and Kantonsspital Luzern, Luzern, Switzerland (B.W.L.D.B.)
| | - Pieter A. Doevendans
- From Maastricht University Medical Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands (J.L., F.W.P., T.D.); University Medical Center Utrecht, Utrecht, The Netherlands (G.E.L., M.J.C., P.A.D.); and Kantonsspital Luzern, Luzern, Switzerland (B.W.L.D.B.)
| | - Frits W. Prinzen
- From Maastricht University Medical Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands (J.L., F.W.P., T.D.); University Medical Center Utrecht, Utrecht, The Netherlands (G.E.L., M.J.C., P.A.D.); and Kantonsspital Luzern, Luzern, Switzerland (B.W.L.D.B.)
| | - Tammo Delhaas
- From Maastricht University Medical Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht, The Netherlands (J.L., F.W.P., T.D.); University Medical Center Utrecht, Utrecht, The Netherlands (G.E.L., M.J.C., P.A.D.); and Kantonsspital Luzern, Luzern, Switzerland (B.W.L.D.B.)
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Hsu SJ, Byram BC, Bouchard RR, Dumont DM, Wolf PD, Trahey GE. Acoustic radiation force impulse imaging of mechanical stiffness propagation in myocardial tissue. ULTRASONIC IMAGING 2012; 34:142-58. [PMID: 22972912 PMCID: PMC3500656 DOI: 10.1177/0161734612456580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Acoustic radiation force impulse (ARFI) imaging has been shown to be capable of imaging local myocardial stiffness changes throughout the cardiac cycle. Expanding on these results, the authors present experiments using cardiac ARFI imaging to visualize and quantify the propagation of mechanical stiffness during ventricular systole. In vivo ARFI images of the left ventricular free wall of two exposed canine hearts were acquired. Images were formed while the heart was externally paced by one of two electrodes positioned on the epicardial surface and either side of the imaging plane. Two-line M-mode ARFI images were acquired at a sampling frequency of 120 Hz while the heart was paced from an external stimulating electrode. Two-dimensional ARFI images were also acquired, and an average propagation velocity across the lateral field of view was calculated. Directions and speeds of myocardial stiffness propagation were measured and compared with the propagations derived from the local electrocardiogram (ECG), strain, and tissue velocity measurements estimated during systole. In all ARFI images, the direction of myocardial stiffness propagation was seen to be away from the stimulating electrode and occurred with similar velocity magnitudes in either direction. When compared with the local epicardial ECG, the mechanical stiffness waves were observed to travel in the same direction as the propagating electrical wave and with similar propagation velocities. In a comparison between ARFI, strain, and tissue velocity imaging, the three methods also yielded similar propagation velocities.
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Vadakkumpadan F, Arevalo H, Ceritoglu C, Miller M, Trayanova N. Image-based estimation of ventricular fiber orientations for personalized modeling of cardiac electrophysiology. IEEE TRANSACTIONS ON MEDICAL IMAGING 2012; 31:1051-60. [PMID: 22271833 PMCID: PMC3518051 DOI: 10.1109/tmi.2012.2184799] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Technological limitations pose a major challenge to acquisition of myocardial fiber orientations for patient-specific modeling of cardiac (dys)function and assessment of therapy. The objective of this project was to develop a methodology to estimate cardiac fiber orientations from in vivo images of patient heart geometries. An accurate representation of ventricular geometry and fiber orientations was reconstructed, respectively, from high-resolution ex vivo structural magnetic resonance (MR) and diffusion tensor (DT) MR images of a normal human heart, referred to as the atlas. Ventricular geometry of a patient heart was extracted, via semiautomatic segmentation, from an in vivo computed tomography (CT) image. Using image transformation algorithms, the atlas ventricular geometry was deformed to match that of the patient. Finally, the deformation field was applied to the atlas fiber orientations to obtain an estimate of patient fiber orientations. The accuracy of the fiber estimates was assessed using six normal and three failing canine hearts. The mean absolute difference between inclination angles of acquired and estimated fiber orientations was 15.4°. Computational simulations of ventricular activation maps and pseudo-ECGs in sinus rhythm and ventricular tachycardia indicated that there are no significant differences between estimated and acquired fiber orientations at a clinically observable level.
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Affiliation(s)
- Fijoy Vadakkumpadan
- Institute for Computational Medicine and Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA.
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29
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Konofagou E, Lee WN, Luo J, Provost J, Vappou J. Physiologic cardiovascular strain and intrinsic wave imaging. Annu Rev Biomed Eng 2012; 13:477-505. [PMID: 21756144 DOI: 10.1146/annurev-bioeng-071910-124721] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cardiovascular disease remains the primary killer worldwide. The heart, essentially an electrically driven mechanical pump, alters its mechanical and electrical properties to compensate for loss of normal mechanical and electrical function. The same adjustment also is performed in the vessels, which constantly adapt their properties to accommodate mechanical and geometrical changes related to aging or disease. Real-time, quantitative assessment of cardiac contractility, conduction, and vascular function before the specialist can visually detect it could be feasible. This new physiologic data could open up interactive therapy regimens that are currently not considered. The eventual goal of this technology is to provide a specific method for estimating the position and severity of contraction defects in cardiac infarcts or angina. This would improve care and outcomes as well as detect stiffness changes and overcome the current global measurement limitations in the progression of vascular disease, at little more cost or risk than that of a clinical ultrasound.
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Affiliation(s)
- Elisa Konofagou
- Ultrasound and Elasticity Imaging Laboratory, Department of Biomedical Engineering, Columbia University, New York, NY 10023, USA.
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30
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Provost J, Thiébaut S, Luo J, Konofagou EE. Single-heartbeat electromechanical wave imaging with optimal strain estimation using temporally unequispaced acquisition sequences. Phys Med Biol 2012; 57:1095-112. [PMID: 22297208 PMCID: PMC4241055 DOI: 10.1088/0031-9155/57/4/1095] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Electromechanical Wave Imaging (EWI) is a non-invasive, ultrasound-based imaging method capable of mapping the electromechanical wave (EW) in vivo, i.e. the transient deformations occurring in response to the electrical activation of the heart. Optimal imaging frame rates, in terms of the elastographic signal-to-noise ratio, to capture the EW cannot be achieved due to the limitations of conventional imaging sequences, in which the frame rate is low and tied to the imaging parameters. To achieve higher frame rates, EWI is typically performed by combining sectors acquired during separate heartbeats, which are then combined into a single view. However, the frame rates achieved remain potentially sub-optimal and this approach precludes the study of non-periodic arrhythmias. This paper describes a temporally unequispaced acquisition sequence (TUAS) for which a wide range of frame rates are achievable independently of the imaging parameters, while maintaining a full view of the heart at high beam density. TUAS is first used to determine the optimal frame rate for EWI in a paced canine heart in vivo and then to image during ventricular fibrillation. These results indicate how EWI can be optimally performed within a single heartbeat, during free breathing and in real time, for both periodic and non-periodic cardiac events.
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Affiliation(s)
- Jean Provost
- Department of Biomedical Engineering, Columbia University, New York, NY
| | - Stéphane Thiébaut
- Department of Biomedical Engineering, Columbia University, New York, NY
| | - Jianwen Luo
- Department of Biomedical Engineering, Columbia University, New York, NY
| | - Elisa E. Konofagou
- Department of Biomedical Engineering, Columbia University, New York, NY
- Department of Radiology, Columbia University, New York, NY
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Electromechanical wave imaging for noninvasive mapping of the 3D electrical activation sequence in canines and humans in vivo. J Biomech 2012; 45:856-64. [PMID: 22284425 DOI: 10.1016/j.jbiomech.2011.11.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/02/2011] [Indexed: 11/22/2022]
Abstract
Cardiovascular diseases rank as America's primary killer, claiming the lives of over 41% of more than 2.4 million Americans. One of the main reasons for this high death toll is the severe lack of effective imaging techniques for screening, early detection and localization of an abnormality detected on the electrocardiogram (ECG). The two most widely used imaging techniques in the clinic are CT angiography and echocardiography with limitations in speed of application and reliability, respectively. It has been established that the mechanical and electrical properties of the myocardium change dramatically as a result of ischemia, infarction or arrhythmia; both at their onset and after survival. Despite these findings, no imaging technique currently exists that is routinely used in the clinic and can provide reliable, non-invasive, quantitative mapping of the regional, mechanical, and electrical function of the myocardium. Electromechanical Wave Imaging (EWI) is an ultrasound-based technique that utilizes the electromechanical coupling and its associated resulting strain to infer to the underlying electrical function of the myocardium. The methodology of EWI is first described and its fundamental performance is presented. Subsequent in vivo canine and human applications are provided that demonstrate the applicability of Electromechanical Wave Imaging in differentiating between sinus rhythm and induced pacing schemes as well as mapping arrhythmias. Preliminary validation with catheter mapping is also provided and transthoracic electromechanical mapping in all four chambers of the human heart is also presented demonstrating the potential of this novel methodology to noninvasively infer to both the normal and pathological electrical conduction of the heart.
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Provost J, Nguyen VTH, Legrand D, Okrasinski S, Costet A, Gambhir A, Garan H, Konofagou EE. Electromechanical wave imaging for arrhythmias. Phys Med Biol 2011; 56:L1-11. [PMID: 22024555 DOI: 10.1088/0031-9155/56/22/f01] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Electromechanical wave imaging (EWI) is a novel ultrasound-based imaging modality for mapping of the electromechanical wave (EW), i.e. the transient deformations occurring in immediate response to the electrical activation. The correlation between the EW and the electrical activation has been established in prior studies. However, the methods used previously to map the EW required the reconstruction of images over multiple cardiac cycles, precluding the application of EWI for non-periodic arrhythmias such as fibrillation. In this study, new imaging sequences are developed and applied based on flash- and wide-beam emissions to image the entire heart at very high frame rates (2000 fps) during free breathing in a single heartbeat. The methods are first validated by imaging the heart of an open-chest canine while simultaneously mapping the electrical activation using a 64-electrode basket catheter. Feasibility is then assessed by imaging the atria and ventricles of closed-chest, conscious canines during sinus rhythm and during right-ventricular pacing following atrio-ventricular dissociation, i.e., during a non-periodic rhythm. The EW was validated against electrode measurements in the open-chest case, and followed the expected electrical propagation pattern in the closed-chest setting. These results indicate that EWI can be used for the characterization of non-periodic arrhythmias in conditions similar to the clinical setting, in a single heartbeat, and during free breathing.
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Affiliation(s)
- Jean Provost
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
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Bourgeois EB, Bachtel AD, Huang J, Walcott GP, Rogers JM. Simultaneous optical mapping of transmembrane potential and wall motion in isolated, perfused whole hearts. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:096020. [PMID: 21950934 PMCID: PMC3194792 DOI: 10.1117/1.3630115] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Optical mapping of cardiac propagation has traditionally been hampered by motion artifact, chiefly due to changes in photodetector-to-tissue registration as the heart moves. We have developed an optical mapping technique to simultaneously record electrical waves and mechanical contraction in isolated hearts. This allows removal of motion artifact from transmembrane potential (V(m)) recordings without the use of electromechanical uncoupling agents and allows the interplay of electrical and mechanical events to be studied at the whole organ level. Hearts are stained with the voltage-sensitive dye di-4-ANEPPS and ring-shaped markers are attached to the epicardium. Fluorescence, elicited on alternate frames by 450 and 505 nm light-emitting diodes, is recorded at 700 frames∕ per second by a camera fitted with a 605 ± 25 nm emission filter. Marker positions are tracked in software. A signal, consisting of the temporally interlaced 450 and 505 nm fluorescence, is collected from the pixels enclosed by each moving ring. After deinterlacing, the 505 nm signal consists of V(m) with motion artifact, while the 450 nm signal is minimally voltage-sensitive and contains primarily artifacts. The ratio of the two signals estimates V(m). Deformation of the tissue enclosed by each set of 3 rings is quantified using homogeneous finite strain.
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Affiliation(s)
- Elliot B Bourgeois
- University of Alabama at Birmingham, Department of Biomedical Engineering, Birmingham, Alabama 35294, USA
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Provost J, Lee WN, Fujikura K, Konofagou EE. Imaging the electromechanical activity of the heart in vivo. Proc Natl Acad Sci U S A 2011; 108:8565-70. [PMID: 21571641 PMCID: PMC3102378 DOI: 10.1073/pnas.1011688108] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cardiac conduction abnormalities remain a major cause of death and disability worldwide. However, as of today, there is no standard clinical imaging modality that can noninvasively provide maps of the electrical activation. In this paper, electromechanical wave imaging (EWI), a novel ultrasound-based imaging method, is shown to be capable of mapping the electromechanics of all four cardiac chambers at high temporal and spatial resolutions and a precision previously unobtainable in a full cardiac view in both animals and humans. The transient deformations resulting from the electrical activation of the myocardium were mapped in 2D and combined in 3D biplane ventricular views. EWI maps were acquired during five distinct conduction configurations and were found to be closely correlated to the electrical activation sequences. EWI in humans was shown to be feasible and capable of depicting the normal electromechanical activation sequence of both atria and ventricles. This validation of EWI as a direct, noninvasive, and highly translational approach underlines its potential to serve as a unique imaging tool for the early detection, diagnosis, and treatment monitoring of arrhythmias through ultrasound-based mapping of the transmural electromechanical activation sequence reliably at the point of care, and in real time.
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Affiliation(s)
- Jean Provost
- Department of Biomedical Engineering, Columbia University, New York, NY 10027; and
| | - Wei-Ning Lee
- Department of Biomedical Engineering, Columbia University, New York, NY 10027; and
| | - Kana Fujikura
- Department of Radiology, Columbia University, New York, NY 10032
| | - Elisa E. Konofagou
- Department of Biomedical Engineering, Columbia University, New York, NY 10027; and
- Department of Radiology, Columbia University, New York, NY 10032
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35
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Provost J, Gurev V, Trayanova N, Konofagou EE. Mapping of cardiac electrical activation with electromechanical wave imaging: an in silico-in vivo reciprocity study. Heart Rhythm 2011; 8:752-9. [PMID: 21185403 PMCID: PMC3100212 DOI: 10.1016/j.hrthm.2010.12.034] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 12/19/2010] [Indexed: 10/18/2022]
Abstract
BACKGROUND Electromechanical wave imaging (EWI) is an entirely noninvasive, ultrasound-based imaging method capable of mapping the electromechanical activation sequence of the ventricles in vivo. Given the broad accessibility of ultrasound scanners in the clinic, the application of EWI could constitute a flexible surrogate for the 3-dimensional electrical activation. OBJECTIVE The purpose of this report is to reproduce the electromechanical wave (EW) using an anatomically realistic electromechanical model, and establish the capability of EWI to map the electrical activation sequence in vivo when pacing from different locations. METHODS EWI was performed in 1 canine during pacing from 3 different sites. A high-resolution dynamic model of coupled cardiac electromechanics of the canine heart was used to predict the experimentally recorded electromechanical wave. The simulated 3-dimensional electrical activation sequence was then compared with the experimental EW. RESULTS The electrical activation sequence and the EW were highly correlated for all pacing sites. The relationship between the electrical activation and the EW onset was found to be linear, with a slope of 1.01 to 1.17 for different pacing schemes and imaging angles. CONCLUSION The accurate reproduction of the EW in simulations indicates that the model framework is capable of accurately representing the cardiac electromechanics and thus testing new hypotheses. The one-to-one correspondence between the electrical activation and the EW sequences indicates that EWI could be used to map the cardiac electrical activity. This opens the door for further exploration of the technique in assisting in the early detection, diagnosis, and treatment monitoring of rhythm dysfunction.
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Affiliation(s)
- Jean Provost
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Viatcheslav Gurev
- Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Natalia Trayanova
- Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Elisa E. Konofagou
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
- Department of Radiology, Columbia University, New York, NY, USA
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Provost J, Lee WN, Fujikura K, Konofagou EE. Electromechanical wave imaging of normal and ischemic hearts in vivo. IEEE TRANSACTIONS ON MEDICAL IMAGING 2010; 29:625-35. [PMID: 19709966 PMCID: PMC3093312 DOI: 10.1109/tmi.2009.2030186] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Electromechanical wave imaging (EWI) has recently been introduced as a noninvasive, ultrasound-based imaging modality, which could map the electrical activation of the heart in various echocardiographic planes in mice, dogs, and humans in vivo. By acquiring radio-frequency (RF) frames at very high frame rates (390-520 Hz), the onset of small, localized, transient deformations resulting from the electrical activation of the heart, i.e., generating the electromechanical wave (EMW), can be mapped. The correlation between the EMW and the electrical activation speed and pacing scheme has previously been reported. In this study, we pursue the development of EWI using both displacements and strains and analysis of the EMW properties in dogs in vivo for early detection of ischemia. EWI was performed in normal and ischemic open-chest dogs during sinus rhythm. Ischemia of increasing severity was obtained by gradually obstructing the left-anterior descending (LAD) coronary artery flow. We also introduce the novel method of motion-matching that achieves the reconstruction of the full EWI ciné-loop at very high frame rates even when the ECG may be irregular or unavailable. Incremental displacements were previously used by our group to map the EMW. This paper focuses on the associated incremental strains, which facilitate the interpretation of the EMW by relating it directly to contraction. Moreover, we define the onset of the EMW as the time, at which the incremental strains change sign after the onset of the QRS complex of the ECG. Based on this definition, isochronal representations of the EMW were generated using a semi-automated method. The isochronal representation of the EMW during sinus rhythm was reproducible and shown similar to electrical activation maps previously reported in the literature. After segmentation using a contour-tracking method, the two- and four-chamber views were imaged and displayed in bi-plane views, allowing a 3-D interpretation of the EMW. EWI was shown to be sensitive to the presence of intermediate ischemia. EWI localized the ischemic region when the LAD flow was obstructed at 60% and beyond and was capable of mapping the increase of the ischemic region size as the LAD occlusion level increased. In conclusion, the activation maps and wave patterns obtained with EWI were similar to the electrical equivalents previously reported in the literature. Moreover, EWI was found to be sensitive enough to detect and map intermediate ischemia. Those results indicate that EWI could be used to assess the conduction properties of the myocardium, and detect its ischemic onset and disease progression entirely noninvasively.
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Affiliation(s)
- Jean Provost
- Department of Biomedical Engineering, Columbia University, New York, NY 10027 USA
| | - Wei-Ning Lee
- Department of Biomedical Engineering, Columbia University, New York, NY 10027 USA
| | - Kana Fujikura
- Department of Biomedical Engineering, Columbia University, New York, NY 10027 USA
| | - Elisa E. Konofagou
- Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027 USA
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Hsu SJ, Bouchard RR, Dumont DM, Ong CW, Wolf PD, Trahey GE. Novel acoustic radiation force impulse imaging methods for visualization of rapidly moving tissue. ULTRASONIC IMAGING 2009; 31:183-200. [PMID: 19771961 PMCID: PMC2810973 DOI: 10.1177/016173460903100304] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Acoustic radiation force impulse (ARFI) imaging has been demonstrated to be capable of visualizing changes in local myocardial stiffness through a normal cardiac cycle. As a beating heart involves rapidly-moving tissue with cyclically-varying myocardial stiffness, it is desirable to form images with high frame rates and minimize susceptibility to motion artifacts. Three novel ARFI imaging methods, pre-excitation displacement estimation, parallel-transmit excitation and parallel-transmit tracking, were implemented. Along with parallel-receive, ECG-gating and multiplexed imaging, these new techniques were used to form high-quality, high-resolution epicardial ARFI images. Three-line M-mode, extended ECG-gated three-line M-mode and ECG-gated two-dimensional ARFI imaging sequences were developed to address specific challenges related to cardiac imaging. In vivo epicardial ARFI images of an ovine heart were formed using these sequences and the quality and utility of the resultant ARFI-induced displacement curves were evaluated. The ARFI-induced displacement curves demonstrate the potential for ARFI imaging to provide new and unique information into myocardial stiffness with high temporal and spatial resolution.
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Affiliation(s)
- Stephen J Hsu
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.
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Sermesant M, Peyrat JM, Chinchapatnam P, Billet F, Mansi T, Rhode K, Delingette H, Razavi R, Ayache N. Toward patient-specific myocardial models of the heart. Heart Fail Clin 2008; 4:289-301. [PMID: 18598981 DOI: 10.1016/j.hfc.2008.02.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This article presents a framework for building patient-specific models of the myocardium, to help diagnosis, therapy planning, and procedure guidance. The aim is to be able to introduce such models in clinical applications. Thus, there is a need to design models that can be adjusted from clinical data, images, or signals, which are sparse and noisy. The authors describe the three main components of a myocardial model: the anatomy, the electrophysiology, and the biomechanics. For each of these components, the authors try to obtain the best balance between prior knowledge and observable parameters to be able to adjust these models to patient data. To achieve this, there is a need to design models with the right level of complexity and a computational cost compatible with clinical constraints.
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Affiliation(s)
- Maxime Sermesant
- Institut National de Recherche en Informatique et en Automatique, Sophia Antipolis, France.
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Prinzen FW, Auricchio A. Is echocardiographic assessment of dyssynchrony useful to select candidates for cardiac resynchronization therapy? Circ Cardiovasc Imaging 2008; 1:70-7; discussion 78. [DOI: 10.1161/circimaging.108.791772] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Frits W. Prinzen
- From the Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, the Netherlands (F.W.P.); and Cardiocentro Ticino, Lugano, Switzerland (A.A.)
| | - Angelo Auricchio
- From the Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, the Netherlands (F.W.P.); and Cardiocentro Ticino, Lugano, Switzerland (A.A.)
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Ashikaga H, Sasano T, Dong J, Zviman MM, Evers R, Hopenfeld B, Castro V, Helm RH, Dickfeld T, Nazarian S, Donahue JK, Berger RD, Calkins H, Abraham MR, Marbán E, Lardo AC, McVeigh ER, Halperin HR. Magnetic resonance-based anatomical analysis of scar-related ventricular tachycardia: implications for catheter ablation. Circ Res 2007; 101:939-47. [PMID: 17916777 DOI: 10.1161/circresaha.107.158980] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In catheter ablation of scar-related monomorphic ventricular tachycardia (VT), substrate voltage mapping is used to electrically define the scar during sinus rhythm. However, the electrically defined scar may not accurately reflect the anatomical scar. Magnetic resonance-based visualization of the scar may elucidate the 3D anatomical correlation between the fine structural details of the scar and scar-related VT circuits. We registered VT activation sequence with the 3D scar anatomy derived from high-resolution contrast-enhanced MRI in a swine model of chronic myocardial infarction using epicardial sock electrodes (n=6, epicardial group), which have direct contact with the myocardium where the electrical signal is recorded. In a separate group of animals (n=5, endocardial group), we also assessed the incidence of endocardial reentry in this model using endocardial basket catheters. Ten to 12 weeks after myocardial infarction, sustained monomorphic VT was reproducibly induced in all animals (n=11). In the epicardial group, 21 VT morphologies were induced, of which 4 (19.0%) showed epicardial reentry. The reentry isthmus was characterized by a relatively small volume of viable myocardium bound by the scar tissue at the infarct border zone or over the infarct. In the endocardial group (n=5), 6 VT morphologies were induced, of which 4 (66.7%) showed endocardial reentry. In conclusion, MRI revealed a scar with spatially complex structures, particularly at the isthmus, with substrate for multiple VT morphologies after a single ischemic episode. Magnetic resonance-based visualization of scar morphology would potentially contribute to preprocedural planning for catheter ablation of scar-related, unmappable VT.
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Affiliation(s)
- Hiroshi Ashikaga
- Division of Cardiology, Johns Hopkins University School of Medicine, 720 Rutland Ave, Traylor 903, Baltimore, MD 20215, USA.
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Klemm HU, Franzen O, Ventura R, Willems S. Catheter based simultaneous mapping of cardiac activation and motion: a review. Indian Pacing Electrophysiol J 2007; 7:148-59. [PMID: 17684573 PMCID: PMC1939867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Heart failure as a result of a variety of cardiac diseases is an ever growing, challenging condition that demands profound insight in the electrical and mechanical state of the myocardium. Assessment of cardiac function has largely relied on evaluation of cardiac motion by multiple imaging techniques. In recent years electrical properties have gained attention as heart failure could be improved by biventricular resynchronization therapy. In contrast to early belief, QRS widening as a result of left bundle branch block could not be identified as a surrogate for asynchronous contraction. The combined analysis of electrical and mechanical function is yet a largely experimental approach. Several mapping system are principally capable for this analysis, the most prominent being the NOGA-XP system. Electromechanical maps have concentrated on the local shortening of the reconstructed endocardial surface from end-diastole to end-systole. Temporal analysis of motion propagation, however, is a new aspect. The fundamental principles of percutaneous catheter based activation and motion assessment are reviewed. Related experimental setups are presented and their main findings discussed.
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Affiliation(s)
- Hanno U Klemm
- Department of Cardiology, University Heart Center Hamburg, Martinistrasse 52, 20246 Hamburg Germany.
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Ciaccio EJ, Ashikaga H, Kaba RA, Cervantes D, Hopenfeld B, Wit AL, Peters NS, McVeigh ER, Garan H, Coromilas J. Model of reentrant ventricular tachycardia based on infarct border zone geometry predicts reentrant circuit features as determined by activation mapping. Heart Rhythm 2007; 4:1034-45. [PMID: 17675078 PMCID: PMC2626544 DOI: 10.1016/j.hrthm.2007.04.015] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2007] [Accepted: 04/07/2007] [Indexed: 11/16/2022]
Abstract
BACKGROUND Infarct border zone (IBZ) geometry likely affects inducibility and characteristics of postinfarction reentrant ventricular tachycardia, but the connection has not been established. OBJECTIVE The purpose of this study was to determine characteristics of postinfarction ventricular tachycardia in the IBZ. METHODS A geometric model describing the relationship between IBZ geometry and wavefront propagation in reentrant circuits was developed. Based on the formulation, slow conduction and block were expected to coincide with areas where IBZ thickness (T) is minimal and the local spatial gradient in thickness (DeltaT) is maximal, so that the degree of wavefront curvature rho proportional, variant DeltaT/T is maximal. Regions of fastest conduction velocity were predicted to coincide with areas of minimum DeltaT. In seven arrhythmogenic postinfarction canine heart experiments, tachycardia was induced by programmed stimulation, and activation maps were constructed from multichannel recordings. IBZ thickness was measured in excised hearts from histologic analysis or magnetic resonance imaging. Reentrant circuit properties were predicted from IBZ geometry and compared with ventricular activation maps after tachycardia induction. RESULTS Mean IBZ thickness was 231 +/- 140 microm at the reentry isthmus and 1440 +/- 770 microm in the outer pathway (P <0.001). Mean curvature rho was 1.63 +/- 0.45 mm(-1) at functional block line locations, 0.71 +/- 0.18 mm(-1) at isthmus entrance-exit points, and 0.33 +/- 0.13 mm(-1) in the outer reentrant circuit pathway. The mean conduction velocity about the circuit during reentrant tachycardia was 0.32 +/- 0.04 mm/ms at entrance-exit points, 0.42 +/- 0.13 mm/ms for the entire outer pathway, and 0.64 +/- 0.16 mm/ms at outer pathway regions with minimum DeltaT. Model sensitivity and specificity to detect isthmus location was 75.0% and 97.2%. CONCLUSIONS Reentrant circuit features as determined by activation mapping can be predicted on the basis of IBZ geometrical relationships.
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Affiliation(s)
- Edward J Ciaccio
- Department of Pharmacology, Columbia University, New York, New York, USA
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44
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Anisotropic elastography for local passive properties and active contractility of myocardium from dynamic heart imaging sequence. Int J Biomed Imaging 2006; 2006:45957. [PMID: 23165032 PMCID: PMC2324035 DOI: 10.1155/ijbi/2006/45957] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Accepted: 09/19/2006] [Indexed: 11/18/2022] Open
Abstract
Major heart diseases such as ischemia and hypertrophic myocardiopathy are accompanied with significant changes in the passive mechanical properties and active contractility of myocardium. Identification of these changes helps diagnose heart diseases, monitor therapy, and design surgery. A dynamic cardiac elastography (DCE) framework is developed to assess the anisotropic viscoelastic passive properties and active contractility of myocardial tissues, based on the chamber pressure and dynamic displacement measured with cardiac imaging techniques. A dynamic adjoint method is derived to enhance the numerical efficiency and stability of DCE. Model-based simulations are conducted using a numerical left ventricle (LV) phantom with an ischemic region. The passive material parameters of normal and ischemic tissues are identified during LV rapid/reduced filling and artery contraction, and those of active contractility are quantified during isovolumetric contraction and rapid/reduced ejection. It is found that quasistatic simplification in the previous cardiac elastography studies may yield inaccurate material parameters.
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McVeigh E. Measuring mechanical function in the failing heart. J Electrocardiol 2006; 39:S24-7. [PMID: 16963066 PMCID: PMC1963464 DOI: 10.1016/j.jelectrocard.2006.05.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Accepted: 05/03/2006] [Indexed: 11/18/2022]
Abstract
A common pathology in heart failure is a detrimental change in the mechanics of both contraction and filling. In familial hypertrophic cardiomyopathy, a genetic disease characterized by left ventricular hypertrophy and myofiber disarray, left ventricular diastolic dysfunction is common and contributes to congestive heart failure. In dilated cardiomyopathy, a common correlate to reduced wall thickening and increased chamber volume is an asynchronous activation of the left ventricle due to left bundle branch block. Local measures of the timing and magnitude of myocardial shortening and relaxation can be obtained with magnetic resonance (MR) tissue tagging, MR cine phase contrast, or MR cine displacement encoding. In familial hypertrophic cardiomyopathy, these methods have been shown to quantify the restrictive filling of the ventricle. Characterizing the regions of the failing heart which are activated late has allowed investigators to measure the change in protein expression in those regions compared to normal myocardium. Also, these MR imaging methods have led to a better quantification of the asynchronous activation in dilated cardiomyopathy, which can be used to predict response to resynchronization therapy with pacing.
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Affiliation(s)
- Elliot McVeigh
- Laboratory of Cardiac Energetics, National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, Bethesda, MD 20892-1061, USA.
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Moreau-Villéger V, Delingette H, Sermesant M, Ashikaga H, McVeigh E, Ayache N. Building maps of local apparent conductivity of the epicardium with a 2-D electrophysiological model of the heart. IEEE Trans Biomed Eng 2006; 53:1457-66. [PMID: 16916080 DOI: 10.1109/tbme.2006.877794] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In this paper, we address the problem of estimating the parameters of an electrophysiological model of the heart from a set of electrical recordings. The chosen model is the reaction-diffusion model on the transmembrane potential proposed by Aliev and Panfilov. For this model of the transmembrane, we estimate a local apparent two-dimensional conductivity from a measured depolarization time distribution. First, we perform an initial adjustment including the choice of initial conditions and of a set of global parameters. We then propose a local estimation by minimizing the quadratic error between the depolarization time computed by the model and the measures. As a first step we address the problem on the epicardial surface in the case of an isotropic version of the Aliev and Panfilov model. The minimization is performed using Brent method without computing the derivative of the error. The feasibility of the approach is demonstrated on synthetic electrophysiological measurements. A proof of concept is obtained on real electrophysiological measures of normal and infarcted canine hearts.
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Sermesant M, Moireau P, Camara O, Sainte-Marie J, Andriantsimiavona R, Cimrman R, Hill DLG, Chapelle D, Razavi R. Cardiac function estimation from MRI using a heart model and data assimilation: advances and difficulties. Med Image Anal 2006; 10:642-56. [PMID: 16765630 DOI: 10.1016/j.media.2006.04.002] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2006] [Revised: 03/24/2006] [Accepted: 04/06/2006] [Indexed: 11/23/2022]
Abstract
In this paper, we present a framework to estimate local ventricular myocardium contractility using clinical MRI, a heart model and data assimilation. First, we build a generic anatomical model of the ventricles including muscle fibre orientations and anatomical subdivisions. Then, this model is deformed to fit a clinical MRI, using a semi-automatic fuzzy segmentation, an affine registration method and a local deformable biomechanical model. An electromechanical model of the heart is then presented and simulated. Finally, a data assimilation procedure is described, and applied to this model. Data assimilation makes it possible to estimate local contractility from given displacements. Presented results on fitting to patient-specific anatomy and assimilation with simulated data are very promising. Current work on model calibration and estimation of patient parameters opens up possibilities to apply this framework in a clinical environment.
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Affiliation(s)
- M Sermesant
- INRIA, team ASCLEPIOS, 2004 route des Lucioles, 06902 Sophia Antipolis, France
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48
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Sermesant M, Delingette H, Ayache N. An electromechanical model of the heart for image analysis and simulation. IEEE TRANSACTIONS ON MEDICAL IMAGING 2006; 25:612-25. [PMID: 16689265 DOI: 10.1109/tmi.2006.872746] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
This paper presents a new three-dimensional electromechanical model of the two cardiac ventricles designed both for the simulation of their electrical and mechanical activity, and for the segmentation of time series of medical images. First, we present the volumetric biomechanical models built. Then the transmembrane potential propagation is simulated, based on FitzHugh-Nagumo reaction-diffusion equations. The myocardium contraction is modeled through a constitutive law including an electromechanical coupling. Simulation of a cardiac cycle, with boundary conditions representing blood pressure and volume constraints, leads to the correct estimation of global and local parameters of the cardiac function. This model enables the introduction of pathologies and the simulation of electrophysiology interventions. Moreover, it can be used for cardiac image analysis. A new proactive deformable model of the heart is introduced to segment the two ventricles in time series of cardiac images. Preliminary results indicate that this proactive model, which integrates a priori knowledge on the cardiac anatomy and on its dynamical behavior, can improve the accuracy and robustness of the extraction of functional parameters from cardiac images even in the presence of noisy or sparse data. Such a model also allows the simulation of cardiovascular pathologies in order to test therapy strategies and to plan interventions.
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Affiliation(s)
- M Sermesant
- INRIA, Epidaure/Asclepios Project, 2004 Route des Lucioles, BP 93, 06 902 Sophia Antipolis, France.
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Goitein O, Lacomis JM, Gorcsan J, Schwartzman D. Left ventricular pacing lead implantation: potential utility of multimodal image integration. Heart Rhythm 2006; 3:91-4. [PMID: 16399062 DOI: 10.1016/j.hrthm.2005.10.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2005] [Accepted: 10/02/2005] [Indexed: 11/19/2022]
Affiliation(s)
- Orly Goitein
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Helm PA, Tseng HJ, Younes L, McVeigh ER, Winslow RL. Ex vivo 3D diffusion tensor imaging and quantification of cardiac laminar structure. Magn Reson Med 2006; 54:850-9. [PMID: 16149057 PMCID: PMC2396270 DOI: 10.1002/mrm.20622] [Citation(s) in RCA: 183] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A three-dimensional (3D) diffusion-weighted imaging (DWI) method for measuring cardiac fiber structure at high spatial resolution is presented. The method was applied to the ex vivo reconstruction of the fiber architecture of seven canine hearts. A novel hypothesis-testing method was developed and used to show that distinct populations of secondary and tertiary eigenvalues may be distinguished at reasonable confidence levels (P < or = 0.01) within the canine ventricle. Fiber inclination and sheet angles are reported as a function of transmural depth through the anterior, lateral, and posterior left ventricle (LV) free wall. Within anisotropic regions, two consistent and dominant orientations were identified, supporting published results from histological studies and providing strong evidence that the tertiary eigenvector of the diffusion tensor (DT) defines the sheet normal.
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Affiliation(s)
- Patrick A Helm
- Center for Cardiovascular Bioinformatics and Modeling, Johns Hopkins University, Baltimore, MD 21218, USA.
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