Does the heart electric activation split upon the infarcted area? An attempt at its detection by high-resolution electrocardiography

Based on the presumption of the activation front splitting, the authors present their own proposal for the estimation of the myocardial electric activation course and for the detection of micropotentials ‘hidden’ within QRS complexes by the method of high-resolution electrocardiography. After filtration of QRS complex the values of delta RMS and those of cumulative amplitudes are calculated from the initial and from the terminal parts of QRS complexes. The presence of late potentials is reflected in a slowing down of the termination of activation course. As compared with healthy subjects, a slower rise of activation was observed in patients with myocardial infarction of the anterior wall. The curves of cumulative amplitudes rose very slowly during the first 70 ms of heart ventricle activation, explained according to the hypothesis of authors as being due to splitting of the activation front at the infarction focus. The usefulness of the proposed method was checked in patients with arterial hypertension and left ventricular hypertrophy, and in a group of patients with myocardial infarction. By the construction of cumulative amplitude curves from the onset of filtered QRS complexes, myocardial foci not reflected by ‘classic’ late potentials can be detected. The partial cumulative amplitudes of the QRS complex are suitable for comparative studies.