Patients with moderate PS, whether native or postintervention, have a good long-term outcome, although some will go on to require an intervention in adulthood because of pro- gressive PS or, commonly, significant PR as a sequela of earlier intervention. Pulmonary atresia with intact ventricular septum is a rare congenital heart lesion that is associated with vary- ing degrees of RV hypoplasia and tricuspid valve hy- poplasia in addition to pulmonary valve atresia. Adults with pulmonary atresia with intact ventricular septum followed various surgical pathways in childhood, ei- ther biventricular repair, 1 1/2 ventricular repair, Fontan procedure, transplant, or shunt palliation.S4.3.1-13 Adults with history of pulmonary atresia with intact ventricu- lar septum have a high incidence of need for reinter- vention and management of atrial arrhythmias.S4.3.1-14, Restrictive RV physiology is common in adults with history of pulmonary atresia with intact ventric- ular septum and may be associated with substantial and RV-dependent coronary circulation. See Section 3.3 for recommendations on who should perform surgeries, cardiac catheterization, and other procedures in these patients; Section 3.4 for rec- ommendations on diagnostic evaluation; Table 23 for routine testing and follow-up intervals; and Figure 3 for a diagnostic and treatment algorithm for isolated PR after repair of PS. Recommendation-Specific Supportive Text 1. In patients with moderate or severe isolated pul- monary valve stenosis, pulmonary balloon val- vuloplasty is safe and effective in reducing the pulmonary valve gradient and improving symp- toms in most patients 2. Surgical valvotomy is usually sufficient, particularly when the pulmonary annulus is not hypoplastic. Pulmonary valve replacement may be necessary Table 22. 