Pulmonary Atresia with Intact Ventricular Septum

Pulmonary atresia with intact ventricular septumPulmonary atresia with intact ventricular septum (PA/IVS) results from membranous or muscular atresia of the right ventricular (RVBorderline right ventricle (RV)) outflow tract and obstruction to antegrade pulmonary blood flow. This results in right ventricular hypertrophy (RVH) with variable RVBorderline right ventricle (RV) size and morphologyMorphology (ranging from normal to diminutive), tricuspid valveTricuspid valve abnormalites including hypoplasia/stenosis/regurgitation, an obligate right-to-left shunt across the atrial septum, and potential coronary artery anomaliesCoronary artery anomaly that include extensive ventriculocoronary connections or RVBorderline right ventricle (RV) dependent coronary circulation (RVDCC). Maintaining patency of the PDAPersistent ductus arteriosus (PDA) is imperative as the source of pulmonary blood flow until cardiac catheterization or surgical interventions are performed. Prognosis and management are contingent on the degree of right ventricular hypertrophy, degree of right ventricleVentricles and tricuspid valveTricuspid valve hypoplasia (z-score), and presence of RVDCC for myocardial perfusionPerfusion. In the absence of RVDCC, establishing antegrade RVBorderline right ventricle (RV) to PA circulation is the priority for patients with adequately sized right ventricleVentricles and tricuspid valveTricuspid valve inflow. Supplemental pulmonary blood flow by PDAPersistent ductus arteriosus (PDA) stenting or BTT shunt may be required while awaiting regression of RVBorderline right ventricle (RV) hypertrophy (RVH) and establishing a biventricular circulation, or as initial single ventricleSingle ventricle palliation. A one-and-a half ventricleVentricles repair with bidirectional cavopulmonary shuntBidirectional cavopulmonary shunt (BCPS) as a second intervention may be required for those with borderline RVBorderline right ventricle (RV) and/or TV size. RVDCC increases in frequency with degree of RVBorderline right ventricle (RV) hypoplasia and is associated with high mortality that may benefit from primary cardiac transplantation and possible high-risk ventricular device support.