Abstract
Since magnetocardiographic signals (MCG) rapidly decay with the distance between the sensor and the electrical source, the conventional recording method over the anterior chest may not provide sufficient information to evaluate the whole heart’s electrical activation. We thus recorded MCGs over both the anterior and posterior chest walls to perform spatiotemporal analysis of intraventricular conduction delay due to complete left and right bundle branch block (CLBBB and CRBBB, respectively) . The end of QRS was semi-automatically determined on anterior and posterior MCGs. In CLBBB, the QRS lasted longer (14±8 msec) in posterior MCGs than in anterior MCGs. In contrast, subjects with CRBBB showed longer QRS in anterior MCGs than that in posterior MCGs. The pseudo-electrical current mapping revealed that the latest activation site in CLBBB was on the left central area of the posterior MCGs (corresponding to the posterior wall of the left ventricle) , while that in CRBBB was on the right central to inferior area of the anterior MCGs (corresponding to the free wall of the right ventricle) . Our data indicated that analysis of anterior and posterior MCGs is useful for quantifying the intraventricular conduction delay due to bundle branch block and localizing the site of conduction delay.
