Premature Ventricular Complexes With 2 QRS Morphologies

BACKGROUND: Premature ventricular complexes (PVCs) from the cardiac crux often have intramural or epicardial substrates, complicating localization and ablation. CASE SUMMARY: and/or precordial differences, suggesting a single crux focus with preferential exits. Proximal coronary sinus mapping did not reveal early activation. Stepwise bilateral endocardial mapping identified the earliest basal inferoseptal activation. Standard irrigated radiofrequency catheter ablation caused only transient suppression. Half-normal saline irrigation at the earliest sites and a discrete prepotential achieved complete PVC elimination. DISCUSSION: This case highlights idiopathic crux PVCs with variable morphologies from an intramural focus with preferential exits. A bilateral endocardial lesion-enhancement strategy may obviate epicardial access. TAKE-HOME MESSAGES: Dual morphologies may share 1 crux focus, and bilateral endocardial mapping and lesion enhancement may be required for successful ablation.