The mechanisms of calcium cycling and action potential dynamics in cardiac alternans.

ABSTRACT:

Rationale

Alternans is a risk factor for cardiac arrhythmia, including atrial fibrillation. At the cellular level alternans manifests as beat-to-beat alternations in contraction, action potential duration (APD), and magnitude of the Ca(2+) transient (CaT). Electromechanical and CaT alternans are highly correlated, however, it has remained controversial whether the primary cause of alternans is a disturbance of cellular Ca(2+) signaling or electrical membrane properties.

Objective

To determine whether a primary failure of intracellular Ca(2+) regulation or disturbances in membrane potential and AP regulation are responsible for the occurrence of alternans in atrial myocytes.

Methods and results

Pacing-induced APD and CaT alternans were studied in single rabbit atrial a

SUBMITTER: Kanaporis G 

PROVIDER: S-EPMC4344847 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature