In 80-90% of the cases, PAPVR is associated with atrial septal defect (ASD)(1).
PAPVR becomes clinically significant when more than 50% of the pulmonary veins are abnormal(1).
Is PAPVR A Progressive Disease?
PAPVR is present from birth, but it is mostly asymptomatic in children and remains undetected; however, cardiac murmurs have been reported incidentally in them. The severity of symptoms depends on the number of pulmonary veins involved, more the veins involved more is the severity of symptoms and associated complications. Usually, the involvement of a single pulmonary vein does not produce any symptoms since it is hemodynamically insignificant. Patients may present with dyspnea (shortness of breath), chest pain, palpitations, arrhythmias, peripheral edema, right heart failure, hemoptysis (blood in sputum), pulmonary vascular disease and pulmonary hypertension in adults. These symptoms are rare in children, who may present with only exercise intolerance in cases of >50% of abnormal pulmonary veins connection(1).
The persistent left to right shunt recirculates the oxygenated blood from pulmonary veins to the right heart, which over a long time causes a progressive increase in pulmonary blood flow and right heart volume overload. Due to these, the right heart and pulmonary vasculature compensate leading to remodeling of the pulmonary vasculature and right heart resulting in pulmonary arterial hypertension and right heart failure(2).
The correct diagnosis of PAPVR is a challenge for the practitioner since the associated symptoms of dyspnea, right heart failure, and pulmonary hypertension are not specific to this disease alone leading to misdiagnosis and delay in surgical repair of the defect(2).
Is There An Alternative Treatment For PAPVR?
Since PAPVR is an abnormal connection of pulmonary veins to the right side of the heart and in around 90% of the cases associated with the atrial septal defect, the definitive treatment is surgical repair and re-anastomosing of the aberrant pulmonary vein and atrial septal defect. There is no alternative treatment for it; however, there is no need for surgery or medicine in asymptomatic cases. There is also no restriction in diet or exercise/activity and the patients can lead a normal and healthy life. Symptomatic patients of arrhythmias, heart failure, and pulmonary hypertension may need to be managed with medications such as beta-blockers, diuretics, and cardiac glycosides(1).
The prognosis of PAPVR is excellent as it is associated with a low mortality and morbidity rate with a perioperative mortality rate of <0.1%.
However, the prognosis decreases if the condition is not diagnosed for a long period and complications, such as pulmonary hypertension develop. Regular follow-up with cardiologist/cardiothoracic surgeon is also important to monitor the condition at regular intervals(1).
PAPVR (Partial Anomalous Pulmonary Venous Return) is a rare heart defect that is present by birth. It is present in only 0.1-0.2% of adult patients. In this, the course of pulmonary veins becomes abnormal as instead of connecting to the left atrium, a few of the pulmonary veins connect to the right side of the heart. Abnormal right pulmonary veins may connect to the right atrium, superior vena cava, inferior vena cava, hepatic vein, azygos vein, or portal vein; whereas, abnormal veins from the left side may connect to the coronary sinus, innominate vein, and hemiazygos vein(2).
PAPVR of the right lung is 2 times more common that PAPVR of the left lung, mainly involving the right upper pulmonary vein and right atrium or superior vena cava. About 80-90% of the PAPVR cases are associated with sinus venosus atrial septal defect (ASD). Isolated PAPVR without any associated ASD involving the abnormal right upper pulmonary vein connecting with superior vena cava is also found, but only on rare occasions.
Another type of PAPVR known as Scimitar syndrome is also detected. This includes the abnormal right pulmonary vein connection to the inferior vena cava with lung sequestration, right lung hypoplasia, and cardiac dextrapositioning to the right. Heterotaxia or PAPVR with complex congenital heart disease is also noted, which is associated with atrial defects(1).