Relation of right ventricular pacing in tetralogy of Fallot to electrical resynchronization.

Prolonged QRS duration is a marker of increased sudden death risk in tetralogy of Fallot. Right ventricular pacing increased QRS duration in this population and could be counteracted with optimization of the atrioventricular interval in a subset of patients, potentially offering right ventricular resynchronization in patients with baseline right bundle branch block. Effective pacing therapy may require site-specific placement of pacing leads and precise pacemaker programming.