Transient narrowing of a wide QRS tachycardia. What is the mechanism?

Francisco RibesÁngel Martínez-BrótonsÁngel Ferrero-De-Loma-OsorioLourdes BondanzaCristina AlbiachVíctor Marcos-GarcésRicardo Ruiz-Granell

Published in: Journal of arrhythmia (2020)

Electrocardiogram showing a regular wide QRS tachycardia with left branch block (LBBB) like in morphology at 200 beats per minute (bpm). During electrophysiology study, it suddenly gets narrow and faster. What is the mechanism of the switch from a broad complex to a narrow complex tachycardia?

Keyphrases

catheter ablation
cardiac resynchronization therapy
atrial fibrillation
cerebral ischemia
brain injury