Interaction of background Ca²⁺ influx, sarcoplasmic reticulum threshold and heart failure in determining propensity for Ca²⁺ waves in sheep heart.

ABSTRACT: Ventricular arrhythmias can cause death in heart failure (HF). A trigger is the occurrence of Ca²⁺ waves which activate a Na⁺ -Ca²⁺ exchange (NCX) current, leading to delayed after-depolarisations and triggered action potentials. Waves arise when sarcoplasmic reticulum (SR) Ca²⁺ content reaches a threshold and are commonly induced experimentally by raising external Ca²⁺ , although the mechanism by which this causes waves is unclear and was the focus of this study. Intracellular Ca²⁺ was measured in voltage-clamped ventricular myocytes from both control sheep and those subjected to rapid pacing to produce HF. Threshold SR Ca²⁺ content was determined by applying caffeine (10  mM) following a wave and integrating wav

SUBMITTER: Hutchings DC 

PROVIDER: S-EPMC9310721 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature