Mechanisms of ventricular arrhythmias in the presence of pathological hypertrophy

Abstract

Ventricular extrasystoles and the complex forms of non-malignant ventricular arrhythmias clearly increase in the presence of left ventricular hypertrophy. Left ventricular hypertrophy constitutes a clear sudden death risk factor. The connection between possible malignant arrhythmias, which have also been reported in LVH patients, and an increased incidence of sudden death has not been established. Hypertension, electrical changes in the hypertrophic myocyte, the growth of the collagen matrix and ischaemia (even in the absence of macro-angiographic injuries) are factors present in this group of patients that contribute to the appearance of arrhythmias. The arrhythmogenic substrate of LVH has to do with reentry mechanisms due to fibrillar stretching and anisotropy, as well as with self-sustaining activity triggered by after-potentials that depend on activation of slow calcium channels.