ABSTRACT
As the most common cyanotic defect, perhaps no other congenital heart disease (CHD) lesion has been more extensively studied than tetralogy of Fallot (TOF). Along with most forms of its sister-lesion, double outlet right ventricle (DORV), successful TOF repair requires relief of right ventricular outflow tract obstruction and ventricular septal defect closure. Whereas initial complete repair techniques utilized a right ventriculotomy and transannular patch to accomplish these goals, modern repairs typically consist of transatrial/transpulmonary incisions in order to spare a ventricular incision and to preserve pulmonary annular integrity. Whether by residual pulmonary regurgitation from a transannular patch or residual pulmonary stenosis by valve-sparing attempts, the right ventricle remains subjected to long-standing hemodynamic stress in most patients. The combination of an atriotomy and right-sided chronic pressure and/or volume load from residual pulmonary valve disease creates the necessary atrial milieu of conduction block, inhomogeneous fibrosis, zones of slow conduction, and chamber dilation that supports wavefront reentry.
