Update on Interventional Electrophysiology in Congenital Heart Disease: Evolving Solutions for Complex Hearts

Cardiac arrhythmias remain a major source of morbidity and mortality for patients with congenital heart disease (CHD). This is especially true for those who underwent successful operative correction or palliation during childhood, only to present decades later with a complex arrhythmogenic substrate caused by their abnormal anatomy, surgical scars, and suboptimal hemodynamics of long duration. Surgical advances are attenuating some of the hemodynamic and suture-related proarrhythmic factors; however, they cannot be eliminated totally and are only part of the puzzle. Inherent preoperative abnormalities and chronic remodeling1,2 continue to affect conduction properties of the myocardium, despite many intelligent modifications in surgical approach.3,4 Although antiarrhythmic medications retain a role under certain circumstances, there is growing reliance on interventional procedures to address rhythm disturbances in children and adults with CHD.5 This article will provide an update on clinical data and technological advances in this field, with a focus on ablation and device therapy. Atrial tachycardias are the most common arrhythmias observed in patients with CHD. They are a major cause of symptomatology, and in some cases they can contribute to sudden cardiac death (SCD). Bouchardy et al6 found in a large cohort of adults with CHD that the prevalence of some type of atrial tachycardia was 15%, with a lifetime risk of ≈50% regardless of severity of the CHD lesion. Atrial arrhythmias were associated with a 50% increase in mortality, a 2-fold increased risk of heart failure or stroke, and a 3-fold higher risk of requiring some major cardiac intervention. Single ventricle patients with a Fontan circulation and those with transposition of the great arteries after Mustard or Senning operations have the highest burden of atrial tachycardia, but even simple atrial septal defect closure can be associated with atrial rhythm disturbances.7 Most atrial tachycardias …