This defect almost always proves fatal in very early life if left untreated. Therefore, the adult patient will have previously undergone a repair operation. Formerly, few patients survived to adulthood, even after treatment, but the prognosis has greatly improved in recent years with the development of new surgical techniques and procedures.

There are different surgical approaches to dealing with this form of pulmonary atresia, each with its own prognosis. These include a "two ventricle" strategy, in which an outflow tract is constructed from the right ventricle into the pulmonary artery with a conduit and prosthetic valve.

"One ventricle" strategies are the Bi-Directional Glenn procedure, in which blood from the body is routed directly from the superior vena cava to the lungs, and the Fontan Procedure, in which blood from the body is routed directly from both the superior vena cava and inferior vena cava to the lungs.

In addition, a "one-and-a half" ventricle approach involves features of both strategies, in which an inadequate but functioning right ventricle is augmented by the direct flow of some blood from the body tissues to the lungs.

Patients who survive the early stages of adjustment and recuperation after this form of treatment may expect a good prognosis and quality of life. Pulmonary stenosis may be present to some degree, but should be tolerated if moderate. There is the danger of right atrial enlargement (dilation), which may result in the development of arrhythmias (irregular heart rates). Other possible symptoms include exercise intolerance, dysfunction of the tricuspid or pulmonary valves, fainting spells (syncope), and sudden death.

The so-called one ventricle solutions may involve a variety of symptoms, such as right atrial enlargement, narrowing of the coronary arteries, cyanosis, high systemic blood pressure, various forms of arrhythmia, angina, and sudden death. The "one and a half" ventricle approach may be attended by cyanosis, arrhythmias, and fatigue, as well as the formation of blood clots and other blood irregularities. However, a study of patients who received the "one ventricle" Fontan operation showed that 80% survived at least 10 years after treatment, and the prognosis continues to improve.

Up to adulthood, children with pulmonary atresia will likely have had multiple cardiac catheterization procedures to enlarge the pulmonary arteries (pulmonary angioplasty and sometimes pulmonary artery stenting) and more than one surgery.  If a right ventricle to pulmonary conduit is used, the valve will deteriorate over time and need to be replaced either surgically or increasingly by cardiac catheterization with a Melody® valve.

Regardless of the kind of operation used in treatment, the patient will need to be carefully monitored for the development of arrhythmias, enlargement of the right atrium, and a reduction in the blood supply to the heart muscle through the coronary arteries (coronary ischemia).

The patient with this defect should expect careful medical follow-up throughout life after treatment.