Electrophysiologic Effects of Carvedilol: Is Carvedilol an Antiarrhythmic Agent?

The cardiovascular drug carvedilol is characterized by multiple pharmacological actions, which translate into a wide‐spectrum therapeutic potential. Its major molecular targets are membrane adrenoceptors, ion channels, and reactive oxygen species. Carvedilol's favorable hemodynamic effects are due to the fact that the drug competitively blocks β 1 ‐, β 2 ‐, and α 1 ‐ adrenoceptors. Several additional properties have been documented and may be clinically important, including antioxidant, antiproliferative/antiatherogenic, anti‐ischemic, and antihypertrophic effects. The antiarrhythmic action of carvedilol may be related to a combination of its β‐blocking effects with its modulating effects on a variety of ion channels and currents. Several studies suggest that the drug may be useful in reducing cardiac death in high‐risk patients with prior myocardial infarction and/or heart failure, as well as for primary and secondary prevention of atrial fibrillation. This article will review experimental data available on the electrophysiologic properties of carvedilol, with a focus on their clinical relevance.