Rauwolfia’s effects on the heart include decreasing myocardial excitability, inhibiting atrial-ventricular conduction, and extending the refractory period of the heart rhythm.1
Much of the medicinal effects of Rauwolfia serpentina and Rauwolfia vomitoria have been attributed
to the hypotensive indole alkaloid reserpine.2Additional alkaloids found in Rauwolfia roots include the indoles ajmaline, ajmalicine, raubasine, imethylajmaline, methylisoajmaline, hydroxysarpagine, yohimbinic acid, and isorauhimbinic acid.3 The constituent ajmaline is thought to be antiarrhythmic.4
Before the advent of the current pharmaceutical options for hypertension (beta blockers, calcium channel blockers, and angiotensin-converting Inhibitors), reserpine was a mainstay in the management of hypertension. Reserpine acts via the CNS to reduce sympathetic tone, increase parasympathetic activity, and help normalize blood pressure, especially when because of stress and sympathetic nervous responses, as it may partially block adrenaline receptors.5 Reserpine’s ability to block adrenoreception on blood vessels can reduce stress-induced vasoconstriction contributing to hypertension or heart palpitations.