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Ventricular arrhythmias in myocardial hypertrophy of various origins
1Department of Internal Medicine, 3rd Medical Faculty, Charles University, Prague, Czech Republic.
Insights
The cause of left ventricular hypertrophy does not affect the occurrence or severity of ventricular arrhythmias. Both essential hypertension and hypertrophic cardiomyopathy showed similar arrhythmia prevalence and types.
Area of Science:
- Cardiology
- Electrophysiology
- Internal Medicine
Background:
- Left ventricular hypertrophy (LVH) can arise from various etiological factors.
- The impact of different LVH substrates on ventricular arrhythmias remains unclear.
Purpose of the Study:
- To compare the prevalence and severity of ventricular arrhythmias in patients with pressure overload hypertrophy (hypertension) versus hypertrophic cardiomyopathy.
- To investigate the relationship between etiological substrate and arrhythmia characteristics in LVH.
Main Methods:
- 48-hour ambulatory electrocardiographic monitoring was performed on two groups of untreated patients.
- Group A (n=42) had LVH from essential hypertension; Group B (n=42) had hypertrophic cardiomyopathy.
- Patients were matched for age, sex, myocardial thickness, and left ventricular systolic function, excluding coronary artery disease.
Main Results:
- Complex ventricular arrhythmias (Lown 3a-4b) were prevalent in both groups (65% vs. 60%, not significant).
- No significant differences in the frequency of severe arrhythmias (Lown 4a, 4b) were observed between groups.
- A correlation existed between complex arrhythmias and maximal myocardial thickness in both groups, and with age in the hypertension group.
Conclusions:
- The etiological substrate of left ventricular hypertrophy does not influence the overall prevalence or spectrum of ventricular arrhythmias.
- Identical prevalence and types of ventricular arrhythmias are seen in pressure overload hypertrophy and hypertrophic cardiomyopathy.
- Maximal myocardial thickness is a common correlate of complex ventricular arrhythmias in different LVH etiologies.
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.