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Harnod Z, Lin C, Yang HW, Wang ZW, Huang HL, Lin TY, Huang CY, Lin LY, Young HWV, Lo MT. A transferable in-silico augmented ischemic model for virtual myocardial perfusion imaging and myocardial infarction detection. Med Image Anal 2024; 93:103087. [PMID: 38244290 DOI: 10.1016/j.media.2024.103087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 03/03/2023] [Accepted: 01/08/2024] [Indexed: 01/22/2024]
Abstract
This paper proposes an innovative approach to generate a generalized myocardial ischemia database by modeling the virtual electrophysiology of the heart and the 12-lead electrocardiography projected by the in-silico model can serve as a ready-to-use database for automatic myocardial infarction/ischemia (MI) localization and classification. Although the virtual heart can be created by an established technique combining the cell model with personalized heart geometry to observe the spatial propagation of depolarization and repolarization waves, we developed a strategy based on the clinical pathophysiology of MI to generate a heterogeneous database with a generic heart while maintaining clinical relevance and reduced computational complexity. First, the virtual heart is simplified into 11 regions that match the types and locations, which can be diagnosed by 12-lead ECG; the major arteries were divided into 3-5 segments from the upstream to the downstream based on the general anatomy. Second, the stenosis or infarction of the major or minor coronary artery branches can cause different perfusion drops and infarct sizes. We simulated the ischemic sites in different branches of the arteries by meandering the infarction location to elaborate on possible ECG representations, which alters the infraction's size and changes the transmembrane potential (TMP) of the myocytes associated with different levels of perfusion drop. A total of 8190 different case combinations of cardiac potentials with ischemia and MI were simulated, and the corresponding ECGs were generated by forward calculations. Finally, we trained and validated our in-silico database with a sparse representation classification (SRC) and tested the transferability of the model on the real-world Physikalisch Technische Bundesanstalt (PTB) database. The overall accuracies for localizing the MI region on the PTB data achieved 0.86, which is only 2% drop compared to that derived from the simulated database (0.88). In summary, we have shown a proof-of-concept for transferring an in-silico model to real-world database to compensate for insufficient data.
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Affiliation(s)
- Zeus Harnod
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan
| | - Chen Lin
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan
| | - Hui-Wen Yang
- Division of Sleep Medicine, Department of Medicine, Harvard Medical School, Boston, USA
| | - Zih-Wen Wang
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan
| | - Han-Luen Huang
- Department of Cardiology, Hsinchu Cathay General Hospital, Hsinchu, Taiwan
| | - Tse-Yu Lin
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan
| | - Chun-Yao Huang
- Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Lian-Yu Lin
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Hsu-Wen V Young
- Department of Electronic Engineering, Chung Yuan Christian University, Taoyuan, Taiwan.
| | - Men-Tzung Lo
- Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan.
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Zhu J, Li M, Liu R. Myocardial ischemia simulation based on a multi-scale heart electrophysiology model. Technol Health Care 2024; 32:27-38. [PMID: 38759037 PMCID: PMC11191480 DOI: 10.3233/thc-248003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/19/2024]
Abstract
BACKGROUND Myocardial ischemia, caused by insufficient myocardial blood supply, is a leading cause of human death worldwide. Therefore, it is crucial to prioritize the prevention and treatment of this condition. Mathematical modeling is a powerful technique for studying heart diseases. OBJECTIVE The aim of this study was to discuss the quantitative relationship between extracellular potassium concentration and the degree of myocardial ischemia directly related to it. METHODS A human cardiac electrophysiological multiscale model was developed to calculate action potentials of all cells simultaneously, enhancing efficiency over traditional reaction-diffusion models. RESULTS Contrary to the commonly held view that myocardial ischemia is caused by an increase in extracellular potassium concentration, our simulation results indicate that level 1 ischemia is associated with a decrease in extracellular potassium concentration. CONCLUSION This unusual finding provides a new perspective on the mechanisms underlying myocardial ischemia and has the potential to lead to the development of new diagnostic and treatment strategies.
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Affiliation(s)
- Junjiang Zhu
- School of Mechanical and Electrical Engineering, China Jiliang University, Hangzhou, Zhejiang, China
| | - Mengyang Li
- School of Mechanical and Electrical Engineering, China Jiliang University, Hangzhou, Zhejiang, China
| | - Renjie Liu
- School of Mechanical and Electrical Engineering, China Jiliang University, Hangzhou, Zhejiang, China
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Okada JI, Washio T, Sugiura S, Hisada T. Transition mechanisms from atrial flutter to atrial fibrillation during anti-tachycardia pacing therapy. Pacing Clin Electrophysiol 2023; 46:1509-1518. [PMID: 37922381 DOI: 10.1111/pace.14863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/11/2023] [Accepted: 10/17/2023] [Indexed: 11/05/2023]
Abstract
BACKGROUND Atrial anti-tachycardia pacing (aATP) has been shown to be effective for the termination of atrial tachyarrhythmias, but its success rate is still not high enough. OBJECTIVE The main objective of this study was to investigate the mechanisms of atrial flutter (AFL) termination by aATP and the transition from AFL to atrial fibrillation (AF) during aATP. METHODS We developed a multi-scale model of the human atrium based on magnetic resonance images and examined the atrial electrophysiology of AFL during aATP with a ramp protocol. RESULTS In successful cases of aATP, paced excitation entered the excitable gap and collided with the leading edge of the reentrant wave front. Furthermore, the excitation propagating in the opposite direction collided with the trailing edge of the reentrant wave to terminate AFL. The second collision was made possible by the distribution of the wave propagation velocity in the atria. The detailed analysis revealed that the slowing of propagation velocity occurred at the exit of the sub-Eustachian isthmus, probably due to source-sink mismatch. During the transition from AFL to AF, the excitation collided with the refractory zone of the preceding wave and broke into multiple wave fronts to induce AF. A similar observation was made for the transition from AF to sinus rhythm. In both cases, the complex anatomy of the atria played an essential role. CONCLUSION The complex anatomy of atria plays an essential role in the maintenance of stable AFL and its termination by aATP, which were revealed by the realistic three-dimensional simulation model.
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Affiliation(s)
- Jun-Ichi Okada
- UT-Heart Inc., Setagaya-ku, Tokyo, Japan
- Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, Japan
| | - Takumi Washio
- UT-Heart Inc., Setagaya-ku, Tokyo, Japan
- Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, Japan
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Okada JI, Washio T, Sugiura S, Hisada T. Low-energy defibrillation using a base-apex epicardial electrode. Pacing Clin Electrophysiol 2023; 46:1325-1332. [PMID: 37830313 DOI: 10.1111/pace.14832] [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: 04/25/2023] [Revised: 08/17/2023] [Accepted: 09/10/2023] [Indexed: 10/14/2023]
Abstract
BACKGROUND Current implantable cardioverter defibrillators (ICDs) require electric conduction with high voltage and high energy, which can impair cardiac function and induce another malignant arrhythmia. As a result, there has been a demand for an ICD that can effectively operate with lower energy to mitigate the risks of a strong electric shock. METHODS A pair of sheet-shaped electrodes covering the heart were analyzed in three configurations (top-bottom, left-right, and front-back) using a heart simulator. We also varied the distance between the two electrodes (clearance) to identify the electrode shape with the lowest defibrillation threshold (DFT). We also investigated the ICD shock waveform, shock direction, and the effect of the backside insulator of the electrode. RESULTS The DFT was high when the clearance was too small and the DFT was high even when the clearance was too large, suggesting that an optimal value clearance. The top-bottom electrodes with optimal clearance showed the lowest DFT when the biphasic shocks set the top electrode to a high potential first and then the bottom electrode was set to a high potential. An interval between a first shock waveform and a second shock waveform should be provided for low-energy defibrillation. Because the insulator prevents unnecessary current flow to the backside, the DFT of the electrodes with insulators is less than those without insulators. CONCLUSION Painless defibrillation using sheet-shaped electrodes on the epicardium is predicated on the basis of results using a heart simulator.
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Affiliation(s)
- Jun-Ichi Okada
- UT-Heart Inc., Setagaya-ku, Tokyo, Japan
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa-shi, Chiba, Japan
| | - Takumi Washio
- UT-Heart Inc., Setagaya-ku, Tokyo, Japan
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa-shi, Chiba, Japan
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Zaichenko KV, Kordyukova AA, Sonin DL, Galagudza MM. Ultra-High-Resolution Electrocardiography Enables Earlier Detection of Transmural and Subendocardial Myocardial Ischemia Compared to Conventional Electrocardiography. Diagnostics (Basel) 2023; 13:2795. [PMID: 37685333 PMCID: PMC10486484 DOI: 10.3390/diagnostics13172795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 08/24/2023] [Accepted: 08/26/2023] [Indexed: 09/10/2023] Open
Abstract
The sensitivity of exercise ECG is marginally sufficient for the detection of mild reduction of coronary blood flow in patients with early coronary atherosclerosis. Here, we describe the application of a new technique of ECG registration/analysis-ultra-high-resolution ECG (UHR ECG)-for early detection of myocardial ischemia (MIS). The utility of UHR ECG vs. conventional ECG (C ECG) was tested in anesthetized rats and pigs. Transmural MIS was induced in rats by the ligation of the left coronary artery (CA). In pigs, subendocardial ischemia of a variable extent was produced by stepwise inflation of a balloon within the right CA, causing a 25-100% reduction of its lumen. In rats, a reduction in power spectral density (PSD) in the high-frequency (HF) channel of UHR ECG was registered at 60 s after ischemia (power 0.81 ± 0.14 vs. 1.25 ± 0.12 mW at baseline, p < 0.01). This was not accompanied by any ST segment elevation on C ECG. In pigs, PSD in the HF channel of UHR ECG was significantly decreased at a 25% reduction of CA lumen, while the ST segment on C ECG remained unchanged. In conclusion, UHR ECG enabled earlier detection of transmural MIS compared to C ECG. PSD in the HF channel of UHR ECG demonstrated greater sensitivity in the settings of subendocardial ischemia.
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Affiliation(s)
- Kirill V. Zaichenko
- Laboratory of Radio- and Optoelectronic Devices for Early Diagnostics of Living Systems Pathologies, The Institute for Analytical Instrumentation, Russian Academy of Sciences, 31-33A Ivana Chernykh Street, 198095 Saint Petersburg, Russia; (K.V.Z.); (D.L.S.)
| | - Anna A. Kordyukova
- Laboratory of Radio- and Optoelectronic Devices for Early Diagnostics of Living Systems Pathologies, The Institute for Analytical Instrumentation, Russian Academy of Sciences, 31-33A Ivana Chernykh Street, 198095 Saint Petersburg, Russia; (K.V.Z.); (D.L.S.)
| | - Dmitry L. Sonin
- Laboratory of Radio- and Optoelectronic Devices for Early Diagnostics of Living Systems Pathologies, The Institute for Analytical Instrumentation, Russian Academy of Sciences, 31-33A Ivana Chernykh Street, 198095 Saint Petersburg, Russia; (K.V.Z.); (D.L.S.)
- Department of Microcirculation and Myocardial Metabolism, Institute of Experimental Medicine, Almazov National Medical Research Centre, 15B Parkhomenko Street, 194021 Saint Petersburg, Russia
| | - Michael M. Galagudza
- Laboratory of Radio- and Optoelectronic Devices for Early Diagnostics of Living Systems Pathologies, The Institute for Analytical Instrumentation, Russian Academy of Sciences, 31-33A Ivana Chernykh Street, 198095 Saint Petersburg, Russia; (K.V.Z.); (D.L.S.)
- Department of Microcirculation and Myocardial Metabolism, Institute of Experimental Medicine, Almazov National Medical Research Centre, 15B Parkhomenko Street, 194021 Saint Petersburg, Russia
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ECG criteria to distinguish hypertrophic cardiomyopathy featured with "Pseudo-STEMI" from acute ST-elevation myocardial infarction. J Electrocardiol 2023; 77:10-16. [PMID: 36527914 DOI: 10.1016/j.jelectrocard.2022.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 11/24/2022] [Accepted: 11/27/2022] [Indexed: 12/13/2022]
Abstract
BACKGROUD The ECG profile of Hypertrophic Cardiomyopathy (HCM) includes ST-segment elevation (STE) that may lead to misdiagnosis of acute ST-segment elevation myocardial infarction (STEMI). This pseudo-STEMI may bring non-essential treatment. We aimed to confirm the ECG differences between HCM featured with pseudo-STEMI and acute STEMI. MATERIAL AND METHODS We retrospectively enrolled 59 HCM cases (Group A) and 56 acute STEMI cases (Group B). Based on the locations of STE, all the patients were divided into four subgroups, including HCM with STE in anterior leads (Group A1), anterior STEMI (Group B1), HCM with STE in inferior leads (Group A2) and inferior STEMI (Group B2). Several ECG parameters were compared between these subgroups. RESULTS ECG parameters significantly differed between these groups, especially the number of leads with TWI. We evaluated the diagnostic value of ECG profiles for those groups. ROC analysis showed that for Group A vs. Group B, number of leads with TWI showed the highest AUC value of 0.805 and its cutoff of 2.5, with 76.3% sensitivity and 76.8% specificity. For Group A1 vs. Group B1, it showed the highest AUC value of 0.801 and its cut-off point was 2.5, with 77.1% sensitivity and 79.1% specificity. For Group A2 vs. Group B2, it showed the highest AUC value of 0.822 and the cut-off value was 4.5, with 54.5% sensitivity and 92.3% specificity. CONCLUSION ECG plays a valid tool to distinguish "Pseudo-STEMI" HCM from acute STEMI, especially number of leads with TWI.
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Kay RT, O’Neill BJ, Taylor D, Senaratne JM. A case of electrical right ventricular infarction in the absence of clinical right ventricular failure. CJC Open 2021; 4:340-343. [PMID: 35386133 PMCID: PMC8978078 DOI: 10.1016/j.cjco.2021.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 11/12/2021] [Indexed: 11/28/2022] Open
Abstract
In the setting of acute coronary syndrome, right-ventricular (RV) infarction, which has significant clinical implications, can occur in conjunction with inferior left-ventricular (LV) infarction. In rare cases, RV infarction is isolated. We describe a case of isolated RV infarction identified based on previously described electrocardiogram findings in the absence of hemodynamic or imaging evidence of RV dysfunction. This case highlights the fact that RV transmural ischemia can exist in the absence of the clinical syndrome associated with RV infarction, which we hypothesize is related to the proportion of RV myocardium involved in the infarct, or conversely, the amount of myocardium protected through various mechanisms.
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Affiliation(s)
- Robert T. Kay
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Division of Cardiology, Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada
- Corresponding author: Robert Kay, Division of Cardiology, University of Alberta Hospital, 2C2, Walter Mackenzie Health Sciences Centre, 8440-112 St, Edmonton, Alberta T6G 2B7, Canada. Tel.: +1-613-898-0104; fax: +1-780-407-6507. @DrRtka
| | - Blair J. O’Neill
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Division of Cardiology, Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada
| | - Dylan Taylor
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Division of Cardiology, Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada
| | - Janek Manoj Senaratne
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Division of Cardiology, Mazankowski Alberta Heart Institute, Edmonton, Alberta, Canada
- Department of Critical Care Medicine, University of Alberta, Edmonton, Alberta, Canada
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