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Roth BJ. The magnetocardiogram. BIOPHYSICS REVIEWS 2024; 5:021305. [PMID: 38827563 PMCID: PMC11139488 DOI: 10.1063/5.0201950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 05/06/2024] [Indexed: 06/04/2024]
Abstract
The magnetic field produced by the heart's electrical activity is called the magnetocardiogram (MCG). The first 20 years of MCG research established most of the concepts, instrumentation, and computational algorithms in the field. Additional insights into fundamental mechanisms of biomagnetism were gained by studying isolated hearts or even isolated pieces of cardiac tissue. Much effort has gone into calculating the MCG using computer models, including solving the inverse problem of deducing the bioelectric sources from biomagnetic measurements. Recently, most magnetocardiographic research has focused on clinical applications, driven in part by new technologies to measure weak biomagnetic fields.
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Affiliation(s)
- Bradley J. Roth
- Department of Physics, Oakland University, Rochester, Michigan 48309, USA
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CUI JG, TIAN F, MIAO YH, JIN QH, SHI YJ, LI L, SHEN MJ, XIE XM, ZHANG SL, CHEN YD. Accurate diagnosis of severe coronary stenosis based on resting magnetocardiography: a prospective, single-center, cross-sectional analysis. J Geriatr Cardiol 2024; 21:407-420. [PMID: 38800545 PMCID: PMC11112152 DOI: 10.26599/1671-5411.2024.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024] Open
Abstract
OBJECTIVE To evaluate the role of resting magnetocardiography in identifying severe coronary artery stenosis in patients with suspected coronary artery disease. METHODS A total of 513 patients with angina symptoms were included and divided into two groups based on the extent of coronary artery disease determined by angiography: the non-severe coronary stenosis group (< 70% stenosis) and the severe coronary stenosis group (≥ 70% stenosis). The diagnostic model was constructed using magnetic field map (MFM) parameters, either individually or in combination with clinical indicators. The performance of the models was evaluated using receiver operating characteristic curves, accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Calibration plots and decision curve analysis were performed to investigate the clinical utility and performance of the models, respectively. RESULTS In the severe coronary stenosis group, QR_MCTDd, S_MDp, and TT_MAC50 were significantly higher than those in the non-severe coronary stenosis group (10.46 ± 10.66 vs. 5.11 ± 6.07, P < 0.001; 7.2 ± 8.64 vs. 4.68 ± 6.95, P = 0.003; 0.32 ± 57.29 vs. 0.26 ± 57.29, P < 0.001). While, QR_MVamp, R_MA, and T_MA in the severe coronary stenosis group were lower (0.23 ± 0.16 vs. 0.28 ± 0.16, P < 0.001; 55.06 ± 48.68 vs. 59.24 ± 53.01, P < 0.001; 51.67 ± 39.32 vs. 60.45 ± 51.33, P < 0.001). Seven MFM parameters were integrated into the model, resulting in an area under the curve of 0.810 (95% CI: 0.765-0.855). The sensitivity, specificity, PPV, NPV, and accuracy were 71.7%, 80.4%, 93.3%, 42.8%, and 73.5%; respectively. The combined model exhibited an area under the curve of 0.845 (95% CI: 0.798-0.892). The sensitivity, specificity, PPV, NPV, and accuracy were 84.3%, 73.8%, 92.6%, 54.6%, and 82.1%; respectively. Calibration curves demonstrated excellent agreement between the nomogram prediction and actual observation. The decision curve analysis showed that the combined model provided greater net benefit compared to the magnetocardiography model. CONCLUSIONS The novel quantitative MFM parameters, whether used individually or in combination with clinical indicators, have been shown to effectively predict the risk of severe coronary stenosis in patients presenting with angina-like symptoms. Magnetocardiography, an emerging non-invasive diagnostic tool, warrants further exploration for its potential in diagnosing coronary heart disease.
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Affiliation(s)
- Jian-Guo CUI
- School of Medicine, Nankai University, Tianjin, China
- Senior Department of Cardiology, the Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Feng TIAN
- Senior Department of Cardiology, the Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Yu-Hao MIAO
- Senior Department of Cardiology, the Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Qin-Hua JIN
- Senior Department of Cardiology, the Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Ya-Jun SHI
- Senior Department of Cardiology, the Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Li LI
- Joint Laboratory of Bioimaging Technology and Applications, SAS-SIMIT & MEDI, Shanghai, China
| | - Meng-Jun SHEN
- Joint Laboratory of Bioimaging Technology and Applications, SAS-SIMIT & MEDI, Shanghai, China
| | - Xiao-Ming XIE
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
| | - Shu-Lin ZHANG
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China
| | - Yun-Dai CHEN
- School of Medicine, Nankai University, Tianjin, China
- Senior Department of Cardiology, the Sixth Medical Center, Chinese PLA General Hospital, Beijing, China
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Kesavaraja C, Sengottuvel S, Patel R, Selvaraj RJ, Satheesh S, Mani A. Enhancing the efficiency and cost-effectiveness of magnetocardiography by optimal channel selection for cardiac diagnosis. Biomed Phys Eng Express 2024; 10:025023. [PMID: 38277702 DOI: 10.1088/2057-1976/ad233e] [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: 11/01/2023] [Accepted: 01/26/2024] [Indexed: 01/28/2024]
Abstract
Background. Magnetocardiography (MCG) is a non-invasive and non-contact technique that measures weak magnetic fields generated by the heart. It is highly effective in the diagnosis of heart abnormalities. Multichannel MCG provides detailed spatio-temporal information of the measured magnetic fields. While multichannel MCG systems are costly, usage of the optimal number of measurement channels to characterize cardiac magnetic fields without any appreciable loss of signal information would be economically beneficial and promote the widespread use of MCG technology.Methods. An optimization method based on the sequential selection approach is used to choose channels containing the maximum signal information while avoiding redundancy. The study comprised 40 healthy individuals, along with two subjects having ischemic heart disease and one subject with premature ventricular contraction. MCG measured using a 37 channel MCG system. After revisiting the existing methods of optimization, the mean error and correlation of the optimal set of measurement channels with those of all 37 channels are evaluated for different sets, and it has been found that 18 channels are adequate.Results. The chosen 18 optimal channels exhibited a strong correlation (0.99 ± 0.006) between the original and reconstructed magnetic field maps for a cardiac cycle in healthy subjects. The root mean square error is 0.295 pT, indicating minimal deviation.Conclusion. This selection method provides an efficient approach for choosing MCG, which could be used for minimizing the number of channels as well as in practical unforeseen measurement conditions where few channels are noisy during the measurement.
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Affiliation(s)
- C Kesavaraja
- Indira Gandhi Centre for Atomic Research, A CI of Homi Bhabha National Institute, Kalpakkam-603102, Tamil Nadu, India
| | - S Sengottuvel
- SQUIDs Applications section, SQUID & Detector Technology Division, Materials Science Group, Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam-603102, Tamil Nadu, India
| | - Rajesh Patel
- SQUIDs Applications section, SQUID & Detector Technology Division, Materials Science Group, Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam-603102, Tamil Nadu, India
| | - Raja J Selvaraj
- Department of Cardiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry-605006, India
| | - Santhosh Satheesh
- Department of Cardiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry-605006, India
| | - Awadhesh Mani
- Indira Gandhi Centre for Atomic Research, A CI of Homi Bhabha National Institute, Kalpakkam-603102, Tamil Nadu, India
- Condensed Matter Physics Division, Materials Science Group, Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam-603102, Tamil Nadu, India
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Brisinda D, Fenici P, Fenici R. Clinical magnetocardiography: the unshielded bet-past, present, and future. Front Cardiovasc Med 2023; 10:1232882. [PMID: 37636301 PMCID: PMC10448194 DOI: 10.3389/fcvm.2023.1232882] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 06/23/2023] [Indexed: 08/29/2023] Open
Abstract
Magnetocardiography (MCG), which is nowadays 60 years old, has not yet been fully accepted as a clinical tool. Nevertheless, a large body of research and several clinical trials have demonstrated its reliability in providing additional diagnostic electrophysiological information if compared with conventional non-invasive electrocardiographic methods. Since the beginning, one major objective difficulty has been the need to clean the weak cardiac magnetic signals from the much higher environmental noise, especially that of urban and hospital environments. The obvious solution to record the magnetocardiogram in highly performant magnetically shielded rooms has provided the ideal setup for decades of research demonstrating the diagnostic potential of this technology. However, only a few clinical institutions have had the resources to install and run routinely such highly expensive and technically demanding systems. Therefore, increasing attempts have been made to develop cheaper alternatives to improve the magnetic signal-to-noise ratio allowing MCG in unshielded hospital environments. In this article, the most relevant milestones in the MCG's journey are reviewed, addressing the possible reasons beyond the currently long-lasting difficulty to reach a clinical breakthrough and leveraging the authors' personal experience since the early 1980s attempting to finally bring MCG to the patient's bedside for many years thus far. Their nearly four decades of foundational experimental and clinical research between shielded and unshielded solutions are summarized and referenced, following the original vision that MCG had to be intended as an unrivaled method for contactless assessment of the cardiac electrophysiology and as an advanced method for non-invasive electroanatomical imaging, through multimodal integration with other non-fluoroscopic imaging techniques. Whereas all the above accounts for the past, with the available innovative sensors and more affordable active shielding technologies, the present demonstrates that several novel systems have been developed and tested in multicenter clinical trials adopting both shielded and unshielded MCG built-in hospital environments. The future of MCG will mostly be dependent on the results from the ongoing progress in novel sensor technology, which is relatively soon foreseen to provide multiple alternatives for the construction of more compact, affordable, portable, and even wearable devices for unshielded MCG inside hospital environments and perhaps also for ambulatory patients.
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Affiliation(s)
- D. Brisinda
- Dipartimento Scienze dell'invecchiamento, ortopediche e reumatologiche, Fondazione Policlinico Universitario Agostino Gemelli, IRCCS, Rome, Italy
- School of Medicine and Surgery, Catholic University of the Sacred Heart, Rome, Italy
- Biomagnetism and Clinical Physiology International Center (BACPIC), Rome, Italy
| | - P. Fenici
- School of Medicine and Surgery, Catholic University of the Sacred Heart, Rome, Italy
- Biomagnetism and Clinical Physiology International Center (BACPIC), Rome, Italy
| | - R. Fenici
- Biomagnetism and Clinical Physiology International Center (BACPIC), Rome, Italy
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Her AY, Dischl D, Kim YH, Kim SW, Shin ES. Magnetocardiography for the detection of myocardial ischemia. Front Cardiovasc Med 2023; 10:1242215. [PMID: 37485271 PMCID: PMC10361573 DOI: 10.3389/fcvm.2023.1242215] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 06/28/2023] [Indexed: 07/25/2023] Open
Abstract
Ischemic heart disease (IHD) continues to be a significant global public health concern and ranks among the leading causes of mortality worldwide. However, the identification of myocardial ischemia in patients suspected of having coronary artery disease (CAD) remains a challenging issue. Functional or stress testing is widely recognized as the gold standard method for diagnosing myocardial ischemia, but it is hindered by low diagnostic accuracy and limitations such as radiation exposure. Magnetocardiography (MCG) is a non-contact, non-invasive method that records magnetic fields produced by the electrical activity of the heart. Unlike electrocardiography (EKG) and other functional or stress testing, MCG offers numerous advantages. It is highly sensitive and can detect early signs of myocardial ischemia that may be missed by other diagnostic tools. This review aims to provide an extensive overview of the available evidence that establishes the utility of MCG as a valuable diagnostic tool for identifying myocardial ischemia, accompanied by a discussion of potential future research directions in this domain.
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Affiliation(s)
- Ae-Young Her
- Department of Internal Medicine, Division of Cardiology, Kangwon National University College of Medicine, Kangwon National University School of Medicine, Chuncheon, Republic of Korea
| | - Dominic Dischl
- Department of Cardiology, Deutsches Herzzentrum der Charité (DHZC), Angiology and Intensive Care Medicine, Berlin, Germany
| | - Yong Hoon Kim
- Department of Internal Medicine, Division of Cardiology, Kangwon National University College of Medicine, Kangwon National University School of Medicine, Chuncheon, Republic of Korea
| | - Sang-Wook Kim
- Heart Research Institute, Cardiovascular-Arrhythmia Center, College of Medicine, Chung-Ang University Hospital, Seoul, Republic of Korea
| | - Eun-Seok Shin
- Department of Cardiology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea
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Huang X, Chen P, Tang F, Hua N. Detection of coronary artery disease in patients with chest pain: A machine learning model based on magnetocardiography parameters. Clin Hemorheol Microcirc 2021; 78:227-236. [PMID: 33337351 DOI: 10.3233/ch-200905] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUD Patients with chest pain and suspected of coronary artery disease(CAD) need further test to confirm the diagnosis. Magnetocardiography (MCG) is a non-invasive and emission-free technology which can detect and measure the weak magnetic fields created by the electrical activity of the heart. OBJECTIVE This study aimed to investigate the usefulness of the 10 MCG parameters to detect CAD in patients with chest pain by means of a machine learning method of multilayer perceptron(MLP) neural network. METHODS 209 patients who were suffering from chest pain and suspected of CAD were enrolled in this cross-sectional study. In all patients, 12-lead electrocardiography(ECG) and MCG test were performed before percutaneous coronary angiography(PCA). 10 MCG parameters were analyzed by MLP neural networks. RESULTS 11 diagnostic models(M1 to M11) were established after MLP analysis. The accuracies ranged from 71.2% to 90.5%. Two models(M10 and M11) were further analyzed. The accuracy, sensitivity, specificity, PPV, NPV, PLR and NLR were 89.5%, 89.8%, 88.9%, 92.7%, 84.7%, 11.10 and 0.11, of M10, and were 90.0%, 91.4%, 87.7%, 92.1%, 86.6%, 7.43 and 0.10, of M11. CONCLUSIONS By a method of MLP neural network, MCG is applicable in identifying CAD in patients with chest pain, which seems beneficial for detection of CAD.
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Affiliation(s)
- Xiao Huang
- Department of Cardiology, The 8th Medical Center, Chinese PLA General Hospital, Bejing, China
| | - Pengfei Chen
- Department of Cardiology, The 8th Medical Center, Chinese PLA General Hospital, Bejing, China
| | - Fakuan Tang
- Department of Cardiology, The 8th Medical Center, Chinese PLA General Hospital, Bejing, China
| | - Ning Hua
- Department of Cardiology, The 8th Medical Center, Chinese PLA General Hospital, Bejing, China
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Goodacre S, Walters SJ, Qayyum H, Coffey F, Carlton E, Coats T, Glazebrook W, Unitt L. Diagnostic accuracy of the magnetocardiograph for patients with suspected acute coronary syndrome. Emerg Med J 2020; 38:47-52. [DOI: 10.1136/emermed-2020-210396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/18/2020] [Accepted: 09/07/2020] [Indexed: 11/03/2022]
Abstract
BackgroundWe aimed to estimate the diagnostic accuracy of the VitalScan magnetocardiograph (MCG) for suspected acute coronary syndrome (ACS).MethodsWe undertook a prospective cohort study evaluating the diagnostic accuracy of the MCG in adults with suspected ACS. The reference standard of ACS was determined by an independent adjudication committee based on 30-day investigations and events. The cohort was split into a training sample, to derive the MCG algorithm and an algorithm combining MCG with a modified Manchester Acute Coronary Syndrome (MACS) clinical probability score, and a validation sample, to estimate diagnostic accuracy.ResultsWe recruited 756 participants and analysed data from 680 (293 training, 387 validation), of whom 96 (14%) had ACS. In the training sample, the respective area under the receiver operating characteristic (AUROC) curves were the following: MCG 0.66 (95% CI 0.58 to 0.74), MACS 0.64 (95% CI 0.54 to 0.73) and MCG+MACS 0.70 (95% CI 0.63 to 0.77). MCG specificity was 0.16 (95% CI 0.12 to 0.21) at the threshold achieving acceptable sensitivity for rule-out (>0.98). In the validation sample (n=387), the respective AUROCs were the following: MCG 0.56 (95% CI 0.48 to 0.64), MACS 0.69 (95% CI 0.61 to 0.77) and MCG+MACS 0.64 (95% CI 0.56 to 0.72). MCG sensitivity was 0.89 (95% CI 0.77 to 0.95) and specificity 0.15 (95% CI 0.12 to 0.20) at the rule-out threshold. MCG+MACS sensitivity was 0.85 (95% CI 0.73 to 0.92) and specificity 0.30 (95% CI 0.25 to 0.35).ConclusionThe VitalScan MCG is currently unable to accurately rule out ACS and is not yet ready for use in clinical practice. Further developmental research is required.
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Huang X, Hua N, Tang F, Zhang S. Effectiveness of magnetocardiography to identify patients in need of coronary artery revascularization: a cross-sectional study. Cardiovasc Diagn Ther 2020; 10:831-840. [PMID: 32968638 PMCID: PMC7487377 DOI: 10.21037/cdt-20-121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 07/09/2020] [Indexed: 07/25/2023]
Abstract
BACKGROUND Patients with angina-like symptoms need invasive or non-invasive angiography to determine whether revascularization is necessary. For patients in need of revascularization, undergoing coronary computed tomography angiography (CCTA) may delay the treatment of revascularization and increase exposure to contrast agents and radiation. The aim of this cross-sectional study was to accessed the effectiveness of magnetocardiography (MCG) to identify patients who should undergo coronary revascularization. METHODS A total of 203 patients who were suffering from angina-like symptoms and underwent percutaneous coronary angiography (PCA) between July 27, 2015 and April 10, 2017 at the 8th Medical Center of Chinese PLA General Hospital, were enrolled in this cross-sectional study. In all patients, 12-lead electrocardiography (ECG) and MCG test were performed before PCA. For each subject. The value at every single sampling point was extracted from T wave of each MCG channel in time sequence. Pearson's correlation coefficients were calculated for each two T-waves. A binary logistic regression diagnosis model of these coefficients was established to identify patients in need of revascularization. RESULTS Ten pairings of coefficients were entered into diagnostic regression model as covariates. The area under the receiver operating characteristic (ROC) curve (AUC) was 0.747 (95% CI: 0.680-0.815), and the asymptotic P value was less than 0.001. At the cut-off value of 0.55, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 72.9%, 65.9%, 74.8%, 63.6% and 69.9%, and the positive and negative post-test probabilities were 65.9% and 25.7%. The accuracy, sensitivity, specificity, PPV and NPV for 12-lead ECG were 67.0%, 62.7%, 63.5%, 70.5% and 55.1%, respectively. However, when those acute myocardial infarction (AMI) patients were ruled out from both groups, the MCG model had an accuracy of 68.2%, a sensitivity of 70.1%, a specificity of 66.3%, a PPV of 68.5% and an NPV of 67.9%. But, the accuracy, sensitivity, specificity, PPV and NPV for 12-lead ECG were 60.0%, 55.2%, 65.1%, 62.3% and 58.1%, respectively. CONCLUSIONS Patients suffering from angina-like symptoms, with a logistic regression model value over 0.55, should be recommended for PCA.
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Affiliation(s)
- Xiao Huang
- Department of Cardiovascular, The 8th Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Ning Hua
- Department of Cardiovascular, The 8th Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Fakuan Tang
- Department of Cardiovascular, The 8th Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Shulin Zhang
- Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai, China
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Swain PP, Sengottuvel S, Patel R, Mani A, Gireesan K. A feasibility study to measure magnetocardiography (MCG) in unshielded environment using first order gradiometer. Biomed Signal Process Control 2020. [DOI: 10.1016/j.bspc.2019.101664] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Shin ES, Chung JH, Park SG, Saleh A, Lam YY, Bhak J, Jung F, Morita S, Brachmann J. Comparison of exercise electrocardiography and magnetocardiography for detection of coronary artery disease using ST-segment fluctuation score. Clin Hemorheol Microcirc 2019; 73:283-291. [DOI: 10.3233/ch-180485] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Eun-Seok Shin
- Department of Cardiology, Ulsan Medical Center, Ulsan Hospital, Ulsan, South Korea
| | - Ju-Hyun Chung
- Department of Cardiology, Ulsan Medical Center, Ulsan Hospital, Ulsan, South Korea
| | - Seung Gu Park
- Korean Genomics Industrialization and Commercialization Center (KOGIC), Ulsan National Institute of Science and Technology (UNIST), Ulsan, South Korea
| | - Ahmed Saleh
- Coburg Hospital, 2nd Medical Department, Coburg, Germany
| | - Yat-Yin Lam
- Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong
| | - Jong Bhak
- Korean Genomics Industrialization and Commercialization Center (KOGIC), Ulsan National Institute of Science and Technology (UNIST), Ulsan, South Korea
- Department of Biomedical Engineering, School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, South Korea
| | - Friedrich Jung
- Institute of Biomaterial Science and Berlin-Brandenburg, Center for Regenerative Therapies (BCRT), Helmholtz Zentrum Geesthacht, Teltow, Germany
| | - Sumio Morita
- Department of Cardiology, Charité Campus Benjamin Franklin, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Bai M, Huang Y, Zhang G, Zheng W, Lin Q, Hu Z. Fast backward singular value decomposition (SVD) algorithm for magnetocardiographic signal reconstruction from pulsed atomic magnetometer data. OPTICS EXPRESS 2019; 27:29534-29546. [PMID: 31684213 DOI: 10.1364/oe.27.029534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 09/17/2019] [Indexed: 06/10/2023]
Abstract
In a pulse pump Rb atomic magnetometer, the magnetic field is associated with the Larmor frequency of the free induction decay (FID) signal. The reconstruction of the magnetic field from the collected signal, thereby, is crucial for magnetocardiography. In this study, we propose a backward singular value decomposition (BSVD) method for fast reconstruction of a magnetocardiographic signal. Experiments on the simulated and real data were performed to estimate its potential advantages over previous approaches, such as the fast Fourier transform (FFT) method, the zero-crossing means (ZM) method, etc. The results show the high accuracy of the BSVD method compared with other methods. More importantly, the BSVD method requires less sampled data than other methods while ensuring the accuracy. With the help of it, the recording time can be greatly reduced from the initial 3.6m s to the present 0.6m s. Thus, the time resolution of the magnetocardiograph could reach 2m s which is equivalent to that of conventional electrocardiogragh. This will bring the atomic magnetocardiography more practicable in clinic application.
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Ramesh R, Senthilnathan S, Satheesh S, Swain PP, Patel R, Ananthakrishna Pillai A, Katholil G, Selvaraj RJ. Magnetocardiography for identification of coronary ischemia in patients with chest pain and normal resting 12-lead electrocardiogram. Ann Noninvasive Electrocardiol 2019; 25:e12715. [PMID: 31587426 PMCID: PMC7358824 DOI: 10.1111/anec.12715] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 09/11/2019] [Accepted: 09/19/2019] [Indexed: 01/17/2023] Open
Abstract
Background Identification of coronary ischemia in patients presenting with chronic chest pain is difficult as resting ECG can be normal. Diagnosis of coronary ischemia requires evaluation during exercise or pharmacological stress. A noninvasive test to identify coronary ischemia at rest without the need for exercise is desirable. We studied the diagnostic accuracy of magnetocardiography (MCG) at rest to detect coronary ischemia in these patients. Methods Patients with chronic chest pain and suspected coronary ischemia with a normal ECG were included. Patients underwent treadmill test (TMT) and were divided into TMT positive and TMT negative groups. MCG was recorded in a magnetically shielded room. Iso‐field contour maps generated at the T‐wave peak were compared between the groups. From the magnetic field map (MFM), the magnetic field angle at T‐wave peak was calculated and was also compared across the two groups. Results There were a total of 29 patients, 12 with positive TMT and 17 with negative TMT. An abnormal magnetic field angle was more common in the TMT positive group (72% vs. 6%). Abnormal contour maps in the form of nondipole patterns or abnormal orientation were seen in 81.8% (9/11) patients in TMT positive group and 6.8% (1/17) patients in the TMT negative group (p < .001). Conclusion Abnormal magnetic field angle and abnormal magnetic field maps in MCG recorded at rest are able to identify the presence of coronary ischemia in patients with chronic chest pain and a normal resting ECG.
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Affiliation(s)
- Raja Ramesh
- Department of Cardiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - Sengottuvel Senthilnathan
- Magnetoencephalography Laboratory, SQUIDs and Applications Section, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India
| | - Santhosh Satheesh
- Department of Cardiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - Pragyna Parimita Swain
- Magnetoencephalography Laboratory, SQUIDs and Applications Section, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India
| | - Rajesh Patel
- Magnetoencephalography Laboratory, SQUIDs and Applications Section, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India
| | - Ajith Ananthakrishna Pillai
- Department of Cardiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
| | - Gireesan Katholil
- Magnetoencephalography Laboratory, SQUIDs and Applications Section, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India
| | - Raja J Selvaraj
- Department of Cardiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
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Shin ES, Park SG, Saleh A, Lam YY, Bhak J, Jung F, Morita S, Brachmann J. Magnetocardiography scoring system to predict the presence of obstructive coronary artery disease. Clin Hemorheol Microcirc 2019; 70:365-373. [DOI: 10.3233/ch-189301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Eun-Seok Shin
- Division of Cardiology, Ulsan Medical Center, Ulsan Hospital, Ulsan, Korea
| | - Seung Gu Park
- Korean Genomics Industrialization and Commercialization Center (KOGIC), Ulsan National Institute of Science and Technology (UNIST), Ulsan, Korea
| | - Ahmed Saleh
- 2nd Medical Department, Coburg Hospital, Coburg, Germany
| | - Yat-Yin Lam
- Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong
| | - Jong Bhak
- Korean Genomics Industrialization and Commercialization Center (KOGIC), Ulsan National Institute of Science and Technology (UNIST), Ulsan, Korea
- Department of Biomedical Engineering, School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Korea
| | - Friedrich Jung
- Institute of Biomaterial Science and Berlin-Brandenburg, Center for Regenerative Therapies (BCRT), Helmholtz Zentrum Geesthacht, Teltow, Germany
| | - Sumio Morita
- Department of Cardiology, Charité Campus Benjamin Franklin, Charité - Universitätsmedizin Berlin, Berlin, Germany
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Shin ES, Park JW, Lim DS. Magnetocardiography for the diagnosis of non-obstructive coronary artery disease1. Clin Hemorheol Microcirc 2018; 69:9-11. [DOI: 10.3233/ch-189106] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Eun-Seok Shin
- Department of Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
- Division of Cardiology, Dietrich Bonhoeffer Hospital, Academic Teaching Hospital of University of Greifswald, Germany
| | - Jai-Wun Park
- Division of Cardiology, Dietrich Bonhoeffer Hospital, Academic Teaching Hospital of University of Greifswald, Germany
| | - Do-Sun Lim
- Department of Cardiology, Cardiovascular Center, Korea University Anam Hospital, Anam-dong, Sungbuk-ku, Seoul, Republic of Korea
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Ghasemi-Roudsari S, Al-Shimary A, Varcoe B, Byrom R, Kearney L, Kearney M. A portable prototype magnetometer to differentiate ischemic and non-ischemic heart disease in patients with chest pain. PLoS One 2018; 13:e0191241. [PMID: 29351337 PMCID: PMC5774725 DOI: 10.1371/journal.pone.0191241] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 12/11/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Magnetocardiography (MCG) is a non-invasive technique used to measure and map cardiac magnetic fields. We describe the predictive performance of a portable prototype magnetometer designed for use in acute and routine clinical settings. We assessed the predictive ability of the measurements derived from the magnetometer for the ruling-out of healthy subjects and patients whose chest pain has a non-ischemic origin from those with ischemic heart disease (IHD). METHODS MCG data were analyzed from a technical performance study, a pilot clinical study, and a young healthy reference group. Participants were grouped to enable differentiation of those with IHD versus non-IHD versus controls: Group A (70 IHD patients); Group B (69 controls); Group C (37 young healthy volunteers). Scans were recorded in an unshielded room. Between-group differences were explored using analysis of variance. The ability of 10 candidate MCG predictors to predict normal/abnormal cases was analyzed using logistic regression. Predictive performance was internally validated using repeated five-fold cross-validation. RESULTS Three MCG predictors showed a significant difference between patients and age-matched controls (P<0.001); eight predictors showed a significant difference between patients and young healthy volunteers (P<0.001). Logistic regression comparing patients with controls yielded a specificity of 35.0%, sensitivity of 95.4%, and negative predictive value for the ruling-out of IHD of 97.8% (area under the curve 0.78). CONCLUSION This analysis represents a preliminary indication that the portable magnetometer can help rule-out healthy subjects and patients whose chest pain has a non-ischemic origin from those with IHD.
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Affiliation(s)
| | - Abbas Al-Shimary
- Department of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
- * E-mail:
| | - Benjamin Varcoe
- Department of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
| | - Rowena Byrom
- Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, United Kingdom
| | - Lorraine Kearney
- Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, United Kingdom
| | - Mark Kearney
- Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, United Kingdom
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Shin ES, Lam YY, Her AY, Brachmann J, Jung F, Park JW. Incremental diagnostic value of combined quantitative and qualitative parameters of magnetocardiography to detect coronary artery disease. Int J Cardiol 2017; 228:948-952. [PMID: 27912204 DOI: 10.1016/j.ijcard.2016.11.165] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 11/06/2016] [Indexed: 11/25/2022]
Abstract
BACKGROUND/OBJECTIVES Magnetocardiography (MCG) has been proposed as a non-invasive and functional technique with high accuracy for diagnosis of myocardial ischemia. This study sought to investigate the incremental diagnostic value of combined quantitative and qualitative parameters of MCG to detect coronary artery disease (CAD). METHODS Ninety six patients with suspected CAD who underwent coronary angiography were enrolled in the analysis to test the diagnostic accuracy of 2 MCG parameters (a quantitative parameter of the percent change of ST-segment fluctuation score and a qualitative parameter of non-dipole phenomenon). RESULTS The best cut-off value for the percent change of ST-segment fluctuation score was -51.0%. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 78.1, 73.9, 82.0, 79.1, and 77.4, in the percent change of ST-segment fluctuation score and 86.5, 84.8, 88.0, 86.7, and 86.3 in non-dipole phenomenon. The area under the curve of receiver-operating characteristics was 0.79 for the percent change of ST-segment fluctuation score and 0.86 for non-dipole phenomenon (p<0.001). However, the incorporation of non-dipole phenomenon into a model with the percent change of ST-segment fluctuation score significantly improved C-statistics, indicating the enhancement of diagnostic performance in the detection of significant CAD (0.790 to 0.930; p<0.001). CONCLUSIONS Qualitative assessment of non-dipole phenomenon has a better diagnostic value than the quantitative parameter of percent change of ST-segment fluctuation score in the detection of significant CAD. Furthermore, this study found that the incorporation of non-dipole phenomenon into the percent change of ST-segment fluctuation score significantly improved the diagnostic performance of CAD detection.
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Affiliation(s)
- Eun-Seok Shin
- Department of Cardiology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, South Korea
| | - Yat-Yin Lam
- Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong
| | - Ae-Young Her
- Division of Cardiology, Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, South Korea
| | | | - Friedrich Jung
- Institute of Biomaterial Science and Berlin-Brandenburg, Center for Regenerative Therapies (BCRT), Helmholtz Zentrum Geesthacht, Teltow, Germany
| | - Jai-Wun Park
- Coburg Hospital, 2nd Medical Department, Coburg, Germany.
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Zhao C, Jiang S, Wu Y, Zhu J, Zhou D, Hailer B, Gronemeyer D, Van Leeuwen P. An Integrated Maximum Current Density Approach for Noninvasive Detection of Myocardial Infarction. IEEE J Biomed Health Inform 2017; 22:495-502. [PMID: 28092581 DOI: 10.1109/jbhi.2017.2649570] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We present a new approach of integrated maximum current density (IMCD) for the noninvasive detection of myocardial infarction (MI) using magnetocardiography (MCG) data acquired from a superconducting quantum interference device (SQUID) system. In this paper, we investigated the relationship of the maximum current density (MCD) in the current density map and the underlying equivalent current dipole (ECD) based on a novel method of reconstructing the ECD in the extremum circle of the magnetic field map. The performance of IMCD and the integrated ECD (IECD) approaches were also evaluated by using 61-channel MCG data from 39 healthy subjects and 102 patients with ST elevation myocardial infarction (STEMI). Statistical analysis of the healthy and STEMI groups demonstrate that the IMCD approach obtains sensitivity and specificity up to 91.2% and 84.6%, somewhat higher than that of IECD, respectively. The results indicate that IMCD provides spatiotemporal information regarding cardiac electrical activity during ventricular repolarization. This approach may be helpful to diagnose MI in clinic application. The physical concept of the approach is also explained in this paper.
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Mooney JW, Ghasemi-Roudsari S, Banham ER, Symonds C, Pawlowski N, Varcoe BTH. A portable diagnostic device for cardiac magnetic field mapping. Biomed Phys Eng Express 2017. [DOI: 10.1088/2057-1976/3/1/015008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Her AY, Park JW. Repolarization Heterogeneity of Magnetocardiography Predicts Long-Term Prognosis in Patients with Acute Myocardial Infarction. Yonsei Med J 2016; 57:1305-6. [PMID: 27593855 PMCID: PMC5011259 DOI: 10.3349/ymj.2016.57.6.1305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Indexed: 11/27/2022] Open
Affiliation(s)
- Ae Young Her
- Division of Cardiology, Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, Korea
- Department of Cardiology, Angiology, and Pneumology, Coburg Hospital, Coburg, Germany
| | - Jai Wun Park
- Department of Cardiology, Angiology, and Pneumology, Coburg Hospital, Coburg, Germany
- Department of Cardiology, Charite University Hospital, Berlin, Germany.
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Bang WD, Kim K, Lee YH, Kwon H, Park Y, Pak HN, Ko YG, Lee M, Joung B. Repolarization Heterogeneity of Magnetocardiography Predicts Long-Term Prognosis in Patients with Acute Myocardial Infarction. Yonsei Med J 2016; 57:1339-46. [PMID: 27593860 PMCID: PMC5011264 DOI: 10.3349/ymj.2016.57.6.1339] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/25/2016] [Accepted: 04/25/2016] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Magnetocardiography (MCG) has been proposed as a noninvasive, diagnostic tool for risk-stratifying patients with acute myocardial infarction (AMI). This study evaluated whether MCG predicts long-term prognosis in AMI. MATERIALS AND METHODS In 124 AMI patients (95 males, mean age 60±11 years), including 39 with ST-elevation myocardial infarction, a 64-channel MCG was performed within 2 days after AMI. During a mean follow-up period of 6.1 years, major adverse cardiac events (MACE) were evaluated. RESULTS MACE occurred in 31 (25%) patients, including 20 revascularizations, 8 deaths, and 3 re-infarctions. Non-dipole patterns were observed at the end of the T wave in every patients. However, they were observed at T-peak in 77% (24/31) and 54% (50/93) of patients with and without MACE, respectively (p=0.03). Maximum current, field map angles, and distance dynamics were not different between groups. In the multivariate analysis, patients with non-dipole patterns at T-peak had increased age- and gender-adjusted hazard ratios for MACE (hazard ratio 2.89, 95% confidence interval 1.20-6.97, p=0.02) and lower cumulative MACE-free survival than those with dipole patterns (p=0.02). CONCLUSION Non-dipole patterns at T-peak were more frequently observed in patients with MACE and were related to poor long-term prognosis. Thus, repolarization heterogeneity measured by MCG may be a useful predictor for AMI prognosis.
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Affiliation(s)
- Woo Dae Bang
- Cardiology Division, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
- Department of Cardiology, University of Ulsan College of Medicine, Gangneung Asan Hospital, Gangneung, Korea
| | - Kiwoong Kim
- Bio-Signal Research Center, Korea Research Institute of Standards and Science, Daejeon, Korea
| | - Yong Ho Lee
- Bio-Signal Research Center, Korea Research Institute of Standards and Science, Daejeon, Korea
| | - Hyukchan Kwon
- Bio-Signal Research Center, Korea Research Institute of Standards and Science, Daejeon, Korea
| | - Yongki Park
- Bio-Signal Research Center, Korea Research Institute of Standards and Science, Daejeon, Korea
| | - Hui Nam Pak
- Cardiology Division, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Young Guk Ko
- Cardiology Division, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Moonhyoung Lee
- Cardiology Division, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Boyoung Joung
- Cardiology Division, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
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Chang YC, Wu CC, Lin CH, Wu YW, Yang YC, Chang TJ, Jiang YD, Chuang LM. Early Myocardial Repolarization Heterogeneity Is Detected by Magnetocardiography in Diabetic Patients with Cardiovascular Risk Factors. PLoS One 2015; 10:e0133192. [PMID: 26185995 PMCID: PMC4505945 DOI: 10.1371/journal.pone.0133192] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 06/23/2015] [Indexed: 11/18/2022] Open
Abstract
Multi-channel magnetocardiography (MCG) is a sensitive technique to map spatial ventricular repolarization with high resolution and reproducibility. Spatial ventricular repolarization heterogeneity measured by MCG has been shown to accurately detect and localize myocardial ischemia. Here, we explored whether these measurements correlated with cardiovascular risk factors in patients with type 2 diabetes. Two hundreds and seventy-seven type 2 diabetic patients without known coronary artery disease (CAD) and arrhythmia were recruited consecutively from the outpatient clinic of National Taiwan University Hospital. The spatially distributed QTc contour maps were constructed with 64-channel MCG using the superconducting quantum interference device (SQUID) system. Indices of myocardial repolarization heterogeneity including the smoothness index of QTc (SI-QTc) and QTc dispersion were derived and analyzed for association with conventional cardiovascular risk factors. SI-QTc correlated strongly with the QTc dispersion (r = 0.70, p <0.0001). SI-QTc was significantly higher in patients with presence of metabolic syndrome in comparison to those without metabolic syndrome (8.56 vs. 7.96 ms, p = 0.02). In univariate correlation analyses, QTc dispersion was associated with smoking status (average 79.90, 83.83, 86.51, and 86.00 ms for never smokers, ex-smokers, current smokers reporting less than 10 cigarettes daily, and current smoker reporting more than 10 cigarettes daily, respectively, p = 0.03), body weight (r = 0.15, p = 0.01), and hemoglobin A1c (r = 0.12, p = 0.04). In stepwise multivariate regression analyses, QTc dispersion was associated with smoking (p = 0.02), body weight (p = 0.04), total cholesterol levels (p = 0.05), and possibly estimated glomerular filtration rate (p = 0.07). In summary, spatial heterogeneity of myocardial repolarization measured by MCG is positively associated cardiovascular risk factors including adiposity, smoking, and total cholesterol levels.
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Affiliation(s)
- Yi-Cheng Chang
- Graduate Institute of Medical Genomics and Proteomics, National Taiwan University, Taipei, Taiwan
- Department of Internal Medicine, National Taiwan University Hospital, HsinChu branch, HsinChu, Taiwan
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Department of Medicine, College of Medicine, National Taiwan University, Taipei; Taiwan
| | - Chau-Chung Wu
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Department of Primary Care Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chih-Hung Lin
- Department of Internal Medicine, Taipei Medical University Hospital, Taipei Taiwan
| | - Yen-Wen Wu
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Department of Nuclear Medicine and Cardiology Division of Cardiovascular Medical Center, Far Eastern Memorial Hospital, New Taipei City, Taiwan
- Departments of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
- National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Ying-Chieh Yang
- Department of Internal Medicine, National Taiwan University Hospital, HsinChu branch, HsinChu, Taiwan
| | - Tien-Jyun Chang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Department of Medicine, College of Medicine, National Taiwan University, Taipei; Taiwan
| | - Yi-Der Jiang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Department of Medicine, College of Medicine, National Taiwan University, Taipei; Taiwan
| | - Lee-Ming Chuang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Department of Medicine, College of Medicine, National Taiwan University, Taipei; Taiwan
- Institute of Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
- * E-mail:
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Spatial repolarization heterogeneity detected by magnetocardiography correlates with cardiac iron overload and adverse cardiac events in beta-thalassemia major. PLoS One 2014; 9:e86524. [PMID: 24475137 PMCID: PMC3903540 DOI: 10.1371/journal.pone.0086524] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Accepted: 12/10/2013] [Indexed: 11/19/2022] Open
Abstract
Background Patients with transfusion-dependent beta-thalassemia major (TM) are at risk for myocardial iron overload and cardiac complications. Spatial repolarization heterogeneity is known to be elevated in patients with certain cardiac diseases, but little is known in TM patients. The purpose of this study was to evaluate spatial repolarization heterogeneity in patients with TM, and to investigate the relationships between spatial repolarization heterogeneity, cardiac iron load, and adverse cardiac events. Methods and Results Fifty patients with TM and 55 control subjects received 64-channel magnetocardiography (MCG) to determine spatial repolarization heterogeneity, which was evaluated by a smoothness index of QTc (SI-QTc), a standard deviation of QTc (SD-QTc), and a QTc dispersion. Left ventricular function and myocardial T2* values were assessed by cardiac magnetic resonance. Patients with TM had significantly greater SI-QTc, SD-QTc, and QTc dispersion compared to the control subjects (all p values<0.001). Spatial repolarization heterogeneity was even more pronounced in patients with significant iron overload (T2*<20 ms, n = 20) compared to those with normal T2* (all p values<0.001). Loge cardiac T2* correlated with SI-QTc (r = −0.609, p<0.001), SD-QTc (r = −0.572, p<0.001), and QTc dispersion (r = −0.622, p<0.001), while all these indices had no relationship with measurements of the left ventricular geometry or function. At the time of study, 10 patients had either heart failure or arrhythmia. All 3 indices of repolarization heterogeneity were related to the presence of adverse cardiac events, with areas under the receiver operating characteristic curves (ranged between 0.79 and 0.86), similar to that of cardiac T2*. Conclusions Multichannel MCG demonstrated that patients with TM had increased spatial repolarization heterogeneity, which is related to myocardial iron load and adverse cardiac events.
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Yang F, Patterson RP. Comparison of magnetocardiography and electrocardiography in diagnosis of cardiac ischemia: a simulation study. Int J Cardiol 2013; 168:3103-6. [PMID: 23651820 DOI: 10.1016/j.ijcard.2013.04.073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 04/06/2013] [Indexed: 10/26/2022]
Affiliation(s)
- Fei Yang
- Washington University School of Medicine, Saint Louis, MO, USA.
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Kwong JSW, Leithäuser B, Park JW, Yu CM. Diagnostic value of magnetocardiography in coronary artery disease and cardiac arrhythmias: a review of clinical data. Int J Cardiol 2013; 167:1835-42. [PMID: 23336954 DOI: 10.1016/j.ijcard.2012.12.056] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 11/27/2012] [Accepted: 12/25/2012] [Indexed: 10/27/2022]
Abstract
Despite the availability of several advanced non-invasive diagnostic tests such as echocardiography and magnetic resonance imaging, electrocardiography (ECG) remains as the most widely used diagnostic technique in clinical cardiology. ECG detects electrical potentials that are generated by cardiac electrical activity. In addition to electrical potentials, the same electrical activity of the heart also induces magnetic fields. These extremely weak cardiac magnetic signals are detected by a non-invasive, contactless technique called magnetocardiography (MCG), which has been evaluated in a number of clinical studies for its usefulness in diagnosing heart diseases. We reviewed the basic principles, history and clinical data on the diagnostic role of MCG in coronary artery disease and cardiac arrhythmias.
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Affiliation(s)
- Joey S W Kwong
- Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR
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Steinisch M, Torke PR, Haueisen J, Hailer B, Grönemeyer D, Van Leeuwen P, Comani S. Early detection of coronary artery disease in patients studied with magnetocardiography: an automatic classification system based on signal entropy. Comput Biol Med 2012; 43:144-53. [PMID: 23260570 DOI: 10.1016/j.compbiomed.2012.11.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Revised: 11/20/2012] [Accepted: 11/22/2012] [Indexed: 01/18/2023]
Abstract
We propose an automatic system for the classification of coronary artery disease (CAD) based on entropy measures of MCG recordings. Ten patients with coronary artery narrowing ≥ or ≤ 50% were categorized by a multilayer perceptron (MLP) neural network based on Linear Discriminant Analysis (LDA). Best results were obtained with MCG at rest: 99% sensitivity, 97% specificity, 98% accuracy, 96% and 99% positive and negative predictive values for single heartbeats. At patient level, these results correspond to a correct classification of all patients. The classifier's suitability to detect CAD-induced changes on the MCG at rest was validated with surrogate data.
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Affiliation(s)
- Martin Steinisch
- Behavioral Imaging and Neural Dynamics Center, G. d'Annunzio University, Via dei Vestini 33, 66013 Chieti, Italy
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Van Leeuwen P, Hailer B, Beck A, Eiling G, Grönemeyer D. Changes in dipolar structure of cardiac magnetic field maps after ST elevation myocardial infarction. Ann Noninvasive Electrocardiol 2011; 16:379-87. [PMID: 22008494 DOI: 10.1111/j.1542-474x.2011.00466.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Pathological changes in cardiac electrophysiology have been investigated in coronary artery disease using magnetocardiography. Aim of this work was to examine the structure of cardiac magnetic field maps (MFM) during ventricular depolarization and repolarization in patients with acute ST elevation myocardial infarction (STEMI). METHODS Magnetocardiograms were recorded in 39 healthy subjects and 97 patients who had been successfully revascularized after STEMI. Using the Karhunen-Loeve transform, 12 eigenmaps were constructed for six intervals within the QT interval of each subject's signal-averaged data. The relative information content of the eigenmaps was compared between STEMI patients and healthy subjects. RESULTS Relative nondipolar content was between 0.03% and 0.52% higher in the STEMI group, (P < 0.001 for the repolarization intervals). Information content of the first dipolar eigenmap in the STEMI group was reduced by 2.6%-11.7% (P < 0.001 for the repolarization intervals). STT interval was best able to discriminate between groups: area-under-the-curve for nondipolar content was 85.8% (P < 0.001), for the first eigenmap 91.7% (P < 0.001). Severity of infarction was reflected in lower STT interval map 1 content for patients with anterior versus posterior infarction (83%± 11% vs. 87%± 10%, P < 0.05), with wall motion disturbances (84%± 11% vs. 92%± 7%, P < 0.001) and with microvascular obstruction (81%± 12% vs. 87%± 10%, P < 0.05). Regression analysis showed that patients with lower ejection fraction tended to have less information content (P < 0.001). CONCLUSION STEMI is associated with a loss of spatial coherence during repolarization, as quantified by principal component analysis of cardiac MFM.
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Affiliation(s)
- Peter Van Leeuwen
- Department of Biomagnetism, Grönemeyer Institute for Microtherapy, University Witten/Herdecke, Universitätsstrasse 142, Bochum, Germany.
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Kandori A, Ogata K, Miyashita T, Takaki H, Kanzaki H, Hashimoto S, Shimizu W, Kamakura S, Watanabe S, Aonuma K. Subtraction magnetocardiogram for detecting coronary heart disease. Ann Noninvasive Electrocardiol 2011; 15:360-8. [PMID: 20946559 DOI: 10.1111/j.1542-474x.2010.00392.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND A large-scale magnetocardiogram (MCG) database was produced, and standard MCG waveforms of healthy patients were calculated by using this database. It was clarified that the standard MCG waveforms are formed with the same shape and current distribution in healthy patients. A new subtraction method for detecting abnormal ST-T waveforms in coronary heart disease (CHD) patients by using the standard MCG waveform was developed. METHODS We used MCGs of 56 CHD patients (63 ± 3 years old) and 101 age-matched normal control patients (65 ± 5 years old). To construct a subtracted ST-T waveform, we used standard MCG waveforms produced from 464 normal MCGs (male: 268, female: 196). The standard MCG waveforms were subtracted from each subject's measured MCGs, which were shortened or lengthened and normalized to adjust to the data length and magnitude of the standard waveform. We evaluated the maximum amplitude and maximum current-arrow magnitude of the subtracted ST-T waveform. RESULTS The maximum magnetic field, maximum magnitude of current arrows, and maximum magnitude of total current vector increased according to the number of coronary artery lesions. The sensitivity and specificity of detecting CHD and normal control patients were 74.6% and 84.1%, respectively. CONCLUSIONS The subtraction MCG method can be used to detect CHD with high accuracy, namely, sensitivity of 74.6% and specificity of 84.1% (in the case of maximum amplitude of total current vector). Furthermore, the subtraction MCG magnitude and its current distribution can reflect the expanse of the ischemic lesion area and the progress from ischemia to myocardial infarction.
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Affiliation(s)
- Akihiko Kandori
- Advanced Research Laboratory, Hitachi Ltd., 1-280 Higashi-Koigakubo, Kokubunji,Tokyo, Japan.
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Kwon H, Kim K, Lee YH, Kim JM, Yu KK, Chung N, Ko YG. Non-Invasive Magnetocardiography for the Early Diagnosis of Coronary Artery Disease in Patients Presenting With Acute Chest Pain. Circ J 2010; 74:1424-30. [DOI: 10.1253/circj.cj-09-0975] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Hyukchan Kwon
- Center for Brain and Cognitive Science Research, Korea Research Institute of Standards and Science
| | - Kiwoong Kim
- Center for Brain and Cognitive Science Research, Korea Research Institute of Standards and Science
| | - Yong-Ho Lee
- Center for Brain and Cognitive Science Research, Korea Research Institute of Standards and Science
| | - Jin-Mok Kim
- Center for Brain and Cognitive Science Research, Korea Research Institute of Standards and Science
| | - Kwon Kyu Yu
- Center for Brain and Cognitive Science Research, Korea Research Institute of Standards and Science
| | - Namsik Chung
- Cardiology Division, Department of Internal Medicine, Yonsei University Medical College
| | - Young-Guk Ko
- Cardiology Division, Department of Internal Medicine, Yonsei University Medical College
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Giugliano RP, Braunwald E. The Year in Non–ST-Segment Elevation Acute Coronary Syndrome. J Am Coll Cardiol 2009; 54:1544-55. [DOI: 10.1016/j.jacc.2009.06.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Accepted: 06/28/2009] [Indexed: 12/19/2022]
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Kyoon Lim H, Kim K, Lee YH, Chung N. Detection of non-ST-elevation myocardial infarction using magnetocardiogram: new information from spatiotemporal electrical activation map. Ann Med 2009; 41:533-46. [PMID: 19626486 DOI: 10.1080/07853890903107883] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
BACKGROUND AND AIM Non-ST-segment elevation myocardial infarction (NSTEMI) cannot be easily detected in the emergency room. We evaluate a method to detect NSTEMI using 64-channel magnetocardiography (MCG). METHODS MCG recordings were made in 20 NSTEMI patients (aged 59.7+/-12.4 years), 15 young (aged 26.8+/-3.4 years), and 13 age-matched control subjects (aged 57.3+/-3.6). We evaluated three approaches to analysis, including 1) determination when individual subjects' MCG results fell outside normal ranges for ten MCG parameters, 2) the magnetic field map at the T-wave peak (T-MFM), and 3) a pair of spatiotemporal activation graphs (STAGs) showing two projections of electrical excitation during repolarization. RESULTS Significant differences were found between normal controls and patients for all MCG parameters. None of the healthy controls had more than four MCG abnormal parameters, whereas 19 NSTEMI patients (95%) were abnormal in more than four parameters. STAGs and T-MFM also showed clear differences between healthy controls and NSTEMI patients. CONCLUSIONS These results suggest that the MCG is sensitive to changes in the cardiac electrical pathway after myocardial infarction as described by these graphs and parameters, and therefore MCG may be a useful tool to detect severe ischemic patients.
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Affiliation(s)
- Hyun Kyoon Lim
- Korea Research Institute of Standards and Science, Daejeon, Korea
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