Association between high grade ventricular arrhythmia and extent of left ventricular hypertrophy in hypertrophic cardiomyopathy.

The association between the extent of left ventricular (LV) hypertrophy and severity of ventricular or atrial arrhythmias are examined. Two-dimensional echocardiography and 24-h Holter electrocardiography monitoring were performed in 60 patients with hypertrophic cardiomyopathy (HCM). According to the distribution of the LV hypertrophy, the patients were divided into three groups: 1. Apical hypertrophy (APH), 2. Septal hypertrophy, and 3. Extensive hypertrophy. Ventricular arrhythmias were found in 82% of the patients and supraventricular arrhythmias were detected in 70% of the patients. Lown grade III and IV arrhythmias occurred significantly more frequently in patients with extensive than with septal hypertrophy. Lown grade III to IV arrhythmias did not occur in patients with APH. Present results show a significant association between the extent of LV hypertrophy and the severity of ventricular arrhythmias in HCM.