Prevalence of arrhythmias during exercise stress testing in patients with hypertrophic cardiomyopathy.

To identify the patients with hypertrophic cardiomyopathy at high risk of morbid events we investigated 25 patients with echocardiographic evidence of hypertrophic cardiomyopathy. All the patients were subjected to submaximal exercise test under electrocardiographic monitoring. More than 50% of the patients developed ventricular arrhythmias, about half of them presenting multiform or repetitive premature ventricular depolarizations; two patients presented ventricular tachycardia. Our results suggest the value of exercise test in identifying the patients at high risk of developing severe arrhythmias.