Shortened Ca2+ signaling refractoriness underlies cellular arrhythmogenesis in a postinfarction model of sudden cardiac death.

ABSTRACT:

Rationale

Diastolic spontaneous Ca(2+) waves (DCWs) are recognized as important contributors to triggered arrhythmias. DCWs are thought to arise when [Ca(2+)] in sarcoplasmic reticulum ([Ca(2+)](SR)) reaches a certain threshold level, which might be reduced in cardiac disease as a consequence of sensitization of ryanodine receptors (RyR2s) to luminal Ca(2+).

Objective

We investigated the mechanisms of DCW generation in myocytes from normal and diseased hearts, using a canine model of post-myocardial infarction ventricular fibrillation (VF).

Methods and results

The frequency of DCWs, recorded during periodic pacing in the presence of a β-adrenergic receptor agonist isoproterenol, was significantly higher in VF myocytes than in normal controls. Rather than occurring imm

SUBMITTER: Belevych AE 

PROVIDER: S-EPMC4068617 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature