Local β-adrenergic stimulation overcomes source-sink mismatch to generate focal arrhythmia.

ABSTRACT:

Rationale

β-Adrenergic receptor stimulation produces sarcoplasmic reticulum Ca(2+) overload and delayed afterdepolarizations in isolated ventricular myocytes. How delayed afterdepolarizations are synchronized to overcome the source-sink mismatch and produce focal arrhythmia in the intact heart remains unknown.

Objective

To determine whether local β-adrenergic receptor stimulation produces spatiotemporal synchronization of delayed afterdepolarizations and to examine the effects of tissue geometry and cell-cell coupling on the induction of focal arrhythmia.

Methods and results

Simultaneous optical mapping of transmembrane potential and Ca(2+) transients was performed in normal rabbit hearts during subepicardial injections (50 μL) of norepinephrine (NE) or control (norma

SUBMITTER: Myles RC 

PROVIDER: S-EPMC3396564 | biostudies-literature | 2012 May

REPOSITORIES: biostudies-literature