Cardiac ion channels

Abstract

Ion channels are critical for all aspects of cardiac function, including rhythmicity and contractility. Consequently, ion channels are key targets for therapeutics aimed at cardiac pathophysiologies such as atrial fibrillation or angina. At the same time, off-target interactions of drugs with cardiac ion channels can be the cause of unwanted side effects. This manuscript aims to review the physiology and pharmacology of key cardiac ion channels. The intent is to highlight recent developments for therapeutic development, as well as elucidate potential mechanisms for drug-induced cardiac side effects, rather than present an in-depth review of each channel subtype.

Keywords: arrhythmia; cardiac function; cardiomyocyte; electrocardiogram; ion channel; pharmacology; vascular tone.

Figure 1.

The top panel shows the ventricular action potential and the currents contributing to each phase. The bottom panel depicts the features and intervals seen in a typical electrocardiogram (e.g., the PR interval is the time between the P wave and the R wave).

Figure 2.

The interplay between voltage-dependent calcium and potassium channels in vascular smooth muscle cells controls blood vessel diameter. Reproduced from. © Blackwell. Reproduced by permission of John Wiley and Sons. Permission to reuse must be obtained from the rightsholder.