This consensus guideline discusses the electrocardiographic phenomenon of beat-to-beat
QT interval variability (QTV) on surface electrocardiograms. The text covers measurement …

Drug-induced ventricular tachyarrhythmias can be caused by cardiovascular drugs,
noncardiovascular drugs, and even nonprescription agents. They can result in arrhythmic …

Cardiac repolarization abnormalities can be caused by a wide range of cardiac and non‐
cardiac compounds and may lead to the development of life‐threatening Torsades de …

Chronic heart failure is a clinical syndrome with multiple etiologies, associated with
significant morbidity and mortality. Cardiac arrhythmias, including ventricular …

Enhanced temporal and spatial variability in cardiac repolarization has been related to
increased arrhythmic risk both clinically and experimentally. Causes and modulators of …

The human ether-à-go-go–related gene (hERG; or KCNH2) encodes the voltage-gated
potassium channel underlying IKr, a repolarizing current in the heart. Mutations in KCNH2 or …

Each heartbeat begins with the generation of an action potential in pacemaking cells in the
sinoatrial node. This signal triggers contraction of cardiac muscle through a process termed …

Rationale: Spontaneous Ca2+ release (SCR) from the sarcoplasmic reticulum can cause
delayed afterdepolarizations and triggered activity, contributing to arrhythmogenesis during …

Beat-to-beat variability of repolarization duration (BVR) is an intrinsic characteristic of
cardiac function and a better marker of proarrhythmia than repolarization prolongation …

Rationale: Clinical reports describe life-threatening cardiac arrhythmias after environmental
exposure to carbon monoxide (CO) or accidental CO poisoning. Numerous case studies …