Non-linear dynamics of cardiac alternans: subcellular to tissue-level mechanisms of arrhythmia

Front Physiol. 2012 May 31;3:157. doi: 10.3389/fphys.2012.00157. eCollection 2012.

Abstract

Cardiac repolarization alternans is a rhythm disturbance of the heart in which rapid stimulation elicits a beat-to-beat alternation in the duration of action potentials and magnitude of intracellular calcium transients in individual cardiac myocytes. Although this phenomenon has been identified as a potential precursor to dangerous reentrant arrhythmias and sudden cardiac death, significant uncertainty remains regarding its mechanism and no clinically practical means of halting its occurrence or progression currently exists. Cardiac alternans has well-characterized tissue, cellular, and subcellular manifestations, the mechanisms and interplay of which are an active area of research.

Keywords: T-wave alternans; calcium handling; cardiac alternans; pattern formation; repolarization alternans; subcellular alternans.