(tachy- + a neg. + Gr. rhythmos rhythm) tachycardia associated with an irregularity in the normal heart rhythm.
<cardiology> A tachycardia associated with an irregularity in the normal heart rhythm. ... Origin: Gr. Rhythmos = rhythm ... (18 Nov 1997) ... 
(tak″e-ә-rith´me-ә) tachycardia associated with arrhythmia. It may be either supraventricular, such as atrial tachycardia, atrial flutter, or atrial fibrillation, or ventricular, such as ventricular tachycardia or ventricular fibrillation.
Type: Term Pronunciation: tak′ē-ă-ridh′mē-ă Definitions: 1. Any disturbance of the heart's rhythm, regular or irregular, resulting by convention in a rate over 100 beats/min during physical examination.
tachyarrhythmia A medical condition in which the hearbeat is fast and irregular.