Magnetocardiography capabilities in myocardium injuries diagnosis

Objective: The electrophysiological properties of the myocardium are extremely heterogeneous. Verification of new magnetocardiography (MCG) signs appears an important aspect for severity assessment of ischemic myocardium damage, ischemic heart disease (IHD) course prognosis, determining of indications for preventive “aggressive” therapy and estimation of its efficacy in patients with IHD. The objective of this research was the investigation of magnetocardiography (MCG) capabilities in diagnosis of ischemic and inflammatory myocardial injuries using new MCG markers of the spatiotemporal organization of myocardium excitation. Methods and results: There were 128 patients examined in three groups. Group 1 contained 34 healthy volunteers. Group 2 contained 62 patients with IHD diagnosis. Group 3 included 32 comparatively young patients with acute myocarditis diagnosis. MCG-mapping of patients was performed at rest on the 7-channel MCG-scanners “Cardiomagscan” V 3.1 (Company KMG, Ukraine) in non-shielded MCG laboratory. 11 MCG markers were determined for selected time intervals of the cardiac cycle. Obtained data provided evidences about significant differences in values of proposed MCG markers for various groups. In patients with AMI, rate of parameters change is higher than without AMI (Sub-groups 2.1 and 2.2 differ by 8 MCG markers). Patients of 2nd and 3rd groups are different from healthy patients by 8 of 11 markers. Analysis of the obtained data has demonstrated good capabilities of MCG in differential diagnostics. Application of discriminatory analysis allowed us to get classification functions, which could be used (with 82% accuracy) to qualify the just examined patient to the investigated categories. Conclusion: Based on the new methodological approach during the studies, the most informative MCG-criteria of space-temporal organization of myocardium excitation in patients with IHD has been proposed. The method is able to distinguish healthy subjects and myocarditis patients and patients with IHD without previous MI with high sensitivity and specificity.