Na/Ca exchange and cardiac ventricular arrhythmias

Ann N Y Acad Sci. 2007 Mar:1099:339-48. doi: 10.1196/annals.1387.066.

Abstract

Ventricular arrhythmias are a major cause of death in cardiovascular disease. Ca2+ removal from the cell by the electrogenic Na/Ca exchanger is essential for the Ca2+ flux balance during excitation-contraction coupling but also contributes to the electrical events. "Classic" views on the exchanger in arrhythmias include its well-recognized role as depolarizing current underlying delayed afterdepolarizations (DADs) during spontaneous Ca2+ release and the alterations in expression in certain forms of cardiac hypertrophy and heart failure. "Novel" views relate to more subtle roles for the exchanger in arrhythmias. Na/Ca exchange function in disease could be modulated indirectly, through phosphorylation or anchoring proteins. Ongoing studies relate Na/Ca exchange to variability in action potential duration (APD) and early afterdepolarizations (EADs) in a dog model of cardiac hypertrophy and arrhythmias. Further research on drugs that target Na/Ca exchange will have to carefully examine the effects on Ca2+ balance.

Publication types

  • Review

MeSH terms

  • Arrhythmias, Cardiac / physiopathology*
  • Heart Ventricles / physiopathology*
  • Humans
  • Sodium-Calcium Exchanger / physiology*

Substances

  • Sodium-Calcium Exchanger