['Propafenone is a well-known Class Ic antiarrhythmic agent. It has the typical chemical structure of a beta-blocker, but human studies on its beta-blocking effects revealed conflicting results.', 'Twelve healthy males received single oral doses of 600 mg propafenone and placebo according to a randomized, double-blind, placebo-controlled, cross-over protocol. Four hours following drug intake, heart rate and blood pressure were measured, and plasma concentrations of propafenone were determined at rest, during exercise and after recovery. At exercise, propafenone significantly decreased heart rate (-6%, P < 0.05), systolic blood pressure (-6%, P < 0.05), and the rate-pressure product (-11%, P < 0.05). Plasma concentrations of propafenone increased during exercise (+23%, P < 0.05) and decreased during recovery (-33%, P < 0.05).'] Does propafenone show class Ic and class II antiarrhythmic effects?