Scopolamine improves autonomic balance in advanced congestive heart failure

Abstract

Background: Sympathetic hyperactivity and parasympathetic withdrawal in patients with congestive heart failure correlate closely with disease severity and overall survival. The modulating effects of drugs on the autonomic dysfunction may contribute to improve survival. Low-dose scopolamine has a vagomimetic effect in normal subjects and patients after acute myocardial infarction. We assessed whether transdermal scopolamine would increase vagal activity in patients with congestive heart failure. Methods and Results: Heart rate variability was assessed at baseline, 24 hours after one patch of transdermal scopolamine, and 48 hours after scopolamine withdrawal in 21 patients with moderate to severe heart failure. Scopolamine increased both time- and frequency-domain parameters of heart rate variability. Specifically, the mean RR interval and its SD increased by 5.5% (P