The Value of Magnetocardiography in Patients with and Without Relevant Stenoses of the Coronary Arteries Using an Unshielded System

Hailer, Birgit; Chaikovsky, Illya; Auth‐Eisernitz, Sabine; Schäfer, H; Leeuwen, P. van

doi:10.1111/j.1540-8159.2005.09318.x

Cited by 47 publications

(47 citation statements)

References 27 publications

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“…Using our method, the presence of CAD is determined by comparing the probability, which was calculated from the prior knowledge on the probability distribution of the MCG parameters depending on the presence of CAD. In this way we obtained better diagnostic accuracy than the previous studies, [11][12][13][14] showing that the proposed method is more effective than the conventional binary decision method. This wMAP method was tested with a small population (86 CAD patients, 59 minimal CAD patients, 66 healthy volunteers) and was applied to all patients to confirm the validity in a relatively large population.…”

Section: Discussionmentioning

confidence: 37%

“…11 In comparison between patients with and without hemodynamic relevant stenosis, a sensitivity of 62.8% and a specificity of 61.3% were reported on analysis of the current density vector. 12 A sensitivity and a specificity of >90% were recently reported in patients admitted to the intensive care unit, using four variables derived during ST-T interval. 13 But in that study 63 out of 264 datasets had to be excluded due to insufficient signal-to-noise ratio, because they measured MCG with a 9-channel system in an unshielded environment.…”

Section: Non-invasive Detection Of Cad By Mcgmentioning

confidence: 99%

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Non-Invasive Magnetocardiography for the Early Diagnosis of Coronary Artery Disease in Patients Presenting With Acute Chest Pain

Kwon

Kim

Lee

et al. 2010

Circ J

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Background: Accurate identification of patients with acute coronary syndrome (ACS) is often difficult especially when an electrocardiogram (ECG) does not show typical elevation of ST segment. The aim of the present study was therefore to evaluate the efficacy of magnetocardiography (MCG) for diagnosis of ACS in patients with acute chest pain presenting without ST segment elevation. Methods and Results:In the present retrospective study 364 patients with the suspected ACS without ST segment elevation were selected. Significant coronary artery disease (CAD) was defined as a stenosis ≥50% in at least one of 16 segments of the 3 major coronary arteries and their branches. The MCG recordings were obtained at resting state using a 64-channel MCG system in a magnetically shielded room. The patients were classified on the basis of the probability distribution. The presence of significant CAD was identified with a sensitivity of 84.0% and a specificity of 85.0%, compared to 44.7% and 89.8% on ECG. In the subgroup of patients without specific findings on ECG or biomarker test, MCG had a sensitivity of 73.5% and a specificity of 82.3%. Conclusions:MCG was acceptably sensitive and specific in identifying patients with ACS even in the absence of specific findings on ECG and positive biomarker tests. Thus, MCG seems beneficial for the early triage of patients with acute chest pain. (Circ J 2010; 74: 1424 - 1430

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Section: Discussionmentioning

confidence: 37%

Section: Non-invasive Detection Of Cad By Mcgmentioning

confidence: 99%

Non-Invasive Magnetocardiography for the Early Diagnosis of Coronary Artery Disease in Patients Presenting With Acute Chest Pain

Kwon

Kim

Lee

et al. 2010

Circ J

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“…Multichannel MCG mapping measures the magnetic fields (MF) generated by cardiac activation currents, with minimal distortion due to the shape and conductivity of the lungs and torso (20, 28). The advantages of contactless MCG mapping are as follows: 1) the ability to study conscious animals without movement artifacts (65), 2) the potential to provide diagnostic information not revealed by ECG (1,29,36,37,41,43,44,51,54,62,64,69,71,74,75), 3) the fixed-sensors geometry (42), which minimizes errors in localization of intracardiac sources (30) and three-dimensional electroanatomic imaging of arrhythmogenic phenomena (77), and 4) the localization of VR heterogeneities associated with areas of myocardial injury (50).A major problem with MCG mapping of small hearts might be an unfavorable signal-to-noise ratio (S/N), because the cardiac sources are very weak. For this reason, most experimental MCG studies of small animal hearts have been performed in magnetically shielded rooms (4,22,23,65,72).…”

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confidence: 99%

Contactless magnetocardiographic mapping in anesthetized Wistar rats: evidence of age-related changes of cardiac electrical activity

Brisinda¹,

Caristo²,

Fenici³

2006

American Journal of Physiology-Heart and Circulatory Physiology

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Brisinda, Donatella, Maria Emiliana Caristo, and Riccardo Fenici. Contactless magnetocardiographic mapping in anesthetized Wistar rats: evidence of age-related changes of cardiac electrical activity. Am J Physiol Heart Circ Physiol 291: H368 -H378, 2006. First published December 22, 2005 doi:10.1152/ajpheart.01048.2005 is the recording of the magnetic field (MF) generated by cardiac electrophysiological activity. Because it is a contactless method, MCG is ideal for noninvasive cardiac mapping of small experimental animals. The aim of this study was to assess age-related changes of cardiac intervals and ventricular repolarization (VR) maps in intact rats by means of MCG mapping. Twenty-four adult Wistar rats (12 male and 12 female) were studied, under anesthesia, with the same unshielded 36-channel MCG instrumentation used for clinical recordings. Two sets of measurements were obtained from each animal: 1) at 5 mo of age (297.5 Ϯ 21 g body wt) and 2) at 14 mo of age (516.8 Ϯ 180 g body wt). RR and PR intervals, QRS segment, and QTpeak, QTend, JTpeak, JTend, and Tpeak-end were measured from MCG waveforms. MCG imaging was automatically obtained as MF maps and as inverse localization of cardiac sources with equivalent current dipole and effective magnetic dipole models. After 300 s of continuous recording were averaged, the signal-to-noise ratio was adequate for study of atrial and ventricular MF maps and for three-dimensional localization of the underlying cardiac sources. Clear-cut age-related differences in VR duration were demonstrated by significantly longer QT end, JTend, and Tpeak-end in older Wistar rats. Reproducible multisite noninvasive cardiac mapping of anesthetized rats is simpler with MCG methodology than with ECG recording. In addition, MCG mapping provides new information based on quantitative analysis of MF and equivalent sources. In this study, statistically significant age-dependent variations in VR intervals were found. magnetocardiography; cardiac mapping; ventricular repolarization; aging; sex ACCORDING TO RECENT GUIDELINES (7,21,26,27,35,39,48,60,63,65), several ECG indexes, such as QT duration and its dispersion, are used to identify risk of sudden death and assess potential cardiotoxicity of new drugs. The latter requires a large number of animal studies in the preclinical phase of new drug development. For noninvasive assessment of ventricular repolarization (VR) in small experimental animals, the most frequently used method is the 12-lead ECG (24). Extensive body surface potential mapping (BSPM), although more sensitive than the standard ECG for evaluation of repolarization inhomogeneity (2,19,38,57,70), is difficult in small animals, and its use is limited (8, 49).Magnetocardiography (MCG), an easier method for simplification of noninvasive cardiac electrophysiological mapping, can be an appealing alternative to BSPM. Multichannel MCG mapping measures the magnetic fields (MF) generated by cardiac activation currents, with minimal distortion due to the shape and conductivity of the lungs...

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“…The magnetic dispersion during the ST-T interval has been reported in patients with coronary heart disease. 15 An interesting finding was the variation of the magnetic dispersion of the late repolarization in association with the temporal ECG changes in the same BS patient. Although our serial MCG data from the same patient was limited, the magnetic dispersion pattern of the repolarization appeared to be more prominent in the coved-type ECGs than in the saddle-back and normal type ECG patterns.…”

Section: Discussionmentioning

confidence: 99%

Magnetic Dispersion of the Late Repolarization in Brugada Syndrome

Joung

Kim

Lee

et al. 2008

Circ J

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Background Magnetocardiography (MCG) is a new noninvasive modality for recording cardiac depolarization and repolarization and was used in the present study to evaluate abnormalities in patients with Brugada syndrome (BS). Methods and ResultsThe MCG findings of 10 BS, 21 right bundle branch block (RBBB), and 34 normal patients were compared. On the horizontal spatiotemporal activation graph (STAG), the r' waves were more frequently located on the right side in the RBBB than in the normal (p=0.001) or BS groups (p=0.001). The maximum current angles of the r' wave fell into the northwest axis in all BS patients as compared to having a right axis deviation in 19 of 21 RBBB patients (90.4%, p=0.001). In the magnetic field and current density vector maps during late repolarization, the BS group had a non-dipole pattern more frequently and a higher number of poles compared with the normal (p=0.001) and RBBB groups (p=0.001). Conclusions During depolarization, the horizontal STAG location and maximum current angle of the r' wave were beneficial in differentiating BS from RBBB and normal. The magnetic dispersion was a more frequently observed finding in BS patients than in RBBB and normal patients during late repolarization. (Circ J 2008; 72: 94 -101)

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The Value of Magnetocardiography in Patients with and Without Relevant Stenoses of the Coronary Arteries Using an Unshielded System

Cited by 47 publications

References 27 publications

Non-Invasive Magnetocardiography for the Early Diagnosis of Coronary Artery Disease in Patients Presenting With Acute Chest Pain

Non-Invasive Magnetocardiography for the Early Diagnosis of Coronary Artery Disease in Patients Presenting With Acute Chest Pain

Contactless magnetocardiographic mapping in anesthetized Wistar rats: evidence of age-related changes of cardiac electrical activity

Magnetic Dispersion of the Late Repolarization in Brugada Syndrome

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