Abstract
It has not been explained whether the etiological substrate of left ventricular hypertrophy has any influence on prevalence and severity of ventricular arrhythmias. Therefore, 48 h ambulatory electrocardiographic monitoring findings were compared in two groups of untreated patients without coronary artery disease and with no significant differences in age, sex, maximal and average myocardial thickness and left ventricular systolic function.
Group A comprised 42 patients with pressure overload hypertrophy due to essential hypertension, and group B comprised 42 patients with hypertrophic cardiomyopathy. The prevalence of complex ventricular arrhythmias (Lown 3a-4b) was high in both groups (65% versus 60%, respectively, not significant).
No significant difference was found in total frequency of most serious arrhythmias: Lown 4a, 26 versus 21 events (not significant), and Lown 4b, 20 versus 28 events (not significant). There was a correlation between prevalence of complex ventricular arrhythmias and maximal myocardial thickness in both groups of patients (P<0.05), and, in group A only, between prevalence of complex ventricular arrhythmias and age (P<0.01).
It was concluded that, although the etiology of pressure overload hypertrophy of the left ventricle and that of hypertrophic cardiomyopathy are completely different, the overall prevalence and spectrum of ventricular arrhythmias in both types of hypertrophy are identical.