Kochav JD, et al. - By performing this retrospective review, researchers investigated whether high ventricular pacing burden is related to adverse consequences among adult Fontan patients. Participants were adult patients with a history of Fontan repair. A high burden of ventricular pacing was defined as ≥ 40% pacing. All-cause death or requirement for advanced cardiac therapies (ventricular assist device or heart transplant) defined major adverse clinical events (MACE). Experts examined 145 cases over a median span of 3.1 years. They found a link of ≥ 40% ventricular-pacing with MACE, independent of initial Fontan type, NYHA functional class at baseline, or history of atrial tachyarrythmia, in multivariable analysis. Findings revealed high ventricular pacing burden as a contributor to poor results in adult Fontan patients, and it needs to be taken into account when deciding optimal management of tachyarrhythmias in this population.