arrhythmia

noun

Etymology: Borrowed from New Latin arrhythmia, from Ancient Greek ἀρρυθμία (arrhuthmía), equivalent to a- + rhythm + -ia.

1. An irregular heartbeat; a lack of a regular pulse.
2. A disease entity involving such beats, such as atrial fibrillation, ventricular tachycardia, AV nodal reentrant tachycardia, or others.