Increased intracellular calcium concentration causes electrical turbulence in guinea pig ventricular myocytes

• DOI: 10.1007/s11427-011-4146-1
• Publication Date: 2011-03-25T19:24:59Z
• Authors: XinRong Fan; JiHua Ma; Wei Wan; PeiHua Zhang; Chao Wang; Lin Wu
• Keywords: Afterdepolarization; Ventricular action potential; Calcium in biology; Homeostasis

Dysregulation of intracellular Ca2+ homeostasis is associated with various pathological conditions and arrhythmogenesis the heart. The objective this study was to investigate effects an acute increase in concentration ([Ca2+]i) on electrophysiology ventricular myocytes by mimicking overload. [Ca2+]i clamped either a controlled (65–100 nmol L−1) or increased (1 μmol level. transmembrane action potentials ionic currents were recorded using whole-cell patch clamp techniques. We found that shortened potential duration, reduced amplitude, maximum depolarization velocity resting membrane potential, caused delayed after-depolarizations (DADs), triggered activity—compared these parameters control. augmented late INa time-dependent manner, ICaL IK1, IKr but not IKs. results can be used explain calcium overload-induced arrhythmias.