Effect of propramolol on circadian variation of ventricular arrhythmias in elderly patients with heart disease and complex ventricular arrhythmias

In our elderly population with prior myocardial infarction or hypertensive heart disease, complex ventricular arrhythmias, and an LV ejection fraction ≥40%, a circadian variation of the maximal number of VPCs per hour was noted in patients before and after no antiarrhythmic drug and before propranolol. The primary peak occurred between 7a.m. and 12p.m. The secondary peak occurred between 6 and 9p.m. in patients before and after no antiarrhythmic drug and between 7 and 8p.m. in patients before treatment with propranolol. However, the circadian variation of the maximal number of VPCs per hour was markedly attenuated by propranolol. This suggests that the sympathetic nervous system contributes to the circadian variation of ventricular arrhythmias as well as to the circadian variation of myocardial infarction or sudden cardiac death.