dyssynchrony
Pronunciation: dis-SIN-kron-ee
Uncoordinated contraction of cardiac chambers or ventricular segments, commonly assessed for cardiac resynchronization therapy.
Full Definition
Cardiac dyssynchrony refers to the loss of coordinated contraction between and within cardiac chambers, most commonly involving the left ventricle. Mechanical dyssynchrony can be assessed by echocardiography, measuring time differences in peak contraction between ventricular segments or walls. Electrical dyssynchrony is identified by widened QRS complexes, typically >120 ms, often with left bundle branch block morphology. Dyssynchrony contributes to reduced cardiac efficiency and is the therapeutic target for cardiac resynchronization therapy (CRT) with biventricular pacing. The presence of significant dyssynchrony, particularly with QRS >150 ms and left bundle branch block, predicts favorable response to CRT.
Usage
Usage note: Specify whether referring to electrical or mechanical dyssynchrony.
In Context
- "Echocardiography revealed significant mechanical dyssynchrony with opposing wall motion between septal and lateral walls." — CRT evaluation report
- "The patient's QRS width of 165 ms with LBBB morphology indicated electrical dyssynchrony suitable for resynchronization therapy." — Electrophysiology consultation