PAPVR is the acronym of partial anomalous venous return and it is a type of heart defect, which sometimes remains present in humans by birth. The disease causes the heart’s pulmonary veins to drain blood within the right atrium instead of draining to the left atrium.(1)
On the other side, PAPVR is a rare disorder in adults and its onset takes place from PAH i.e. pulmonary arterial hypotension, which presents severity starting from early childhood to adult phase of a patient.(2)
The continuous flow of oxygen-rich blood between the right atrium and the lungs results in dilation of the right chambers of one’s heart. With time, the disease leads to abnormal heart rhythm i.e. the condition of arrhythmia. Moreover, the excessive flow of blood towards the lungs may increase the blood vessels’ pressure of the lungs. This leads to a condition of pulmonary hypertension.(3)
How Common Is PAPVR Or Is It A Rare Disease?
PAPVR is a type of uncommon or rare congenital abnormality. The problem takes place only in 0.4percent to 0.7percent of the individuals kept under examination. About 90percent of the anomalies mentioned here have a close association with the atrial septal defect.
According to the experts, a partial anomalous pulmonary venous return takes place commonly in the right area as compared to the left one. The problem manifests abnormal return of various pulmonary veins towards the circulation of central veins. Most of the PAPVR patients are asymptomatic. However, symptoms, in this case, take place because of the shunting of oxygenated blood towards the venous circulation.(4)
PAPVR Is A Rare Defect, Which Causes During Embryogenesis
Research studies have also revealed that PAPVR takes place as a rare type of development defect at the time of embryogenesis. In this case, a few of the entire pulmonary veins drain within the systemic veins or the right atrium without or with pulmonary venous obstruction. The problem thus leads to different manifestations, like pulmonary arterial hypertension, exertion dyspnea, fatigue, cyanosis, and congestive progressive heart failure. PAPVR has two major subtypes i.e. congenital partial problem, where only some of the pulmonary veins are of the anomalous and congenital total problem, where each of the pulmonary veins is of anomalous type.(4)
PAPVR Is Rare According To The Type Of Defect
Moreover, we can say that partial anomalous pulmonary venous return is a rare disease because 40percent of patients suffer from right-sided PAPVR or PAPVC because of atrial septal defects. Furthermore, the problem is rare with patients, who have ostium primum defects i.e. a specific type of atrioventricular defect.(5)
PAPVR Is Uncommon Based On Its Four Different Types
According to cardiologists, PAPVR takes place in four different types-
Supra-cardiac PAPVR: Even though PAPVR is rare, many patients suffer from supra-cardiac types, like-
- Right superior vena cava, which is a common one
- Persistent type of left superior vena cava
- Innominate veins i.e. brachiocephalic veins
Cardiac PAPVR: This type of PAPVR takes place in two different forms i.e. coronary sinus and right atrium.
Infra Cardiac PAPVR: Infra cardiac is relatively less type of PAPVR and its major categories are-
- Hepatic veins
- Portal veins
- An inferior type of vena cava i.e. Scimitar syndrome
Mixed PAPVR: As the name highlights, a mixed type of PAPVR contains a combination of multiple anomalies mentioned here. This is the rarest type of partial anomalous pulmonary venous return.(5)
To conclude, we should say that PAPVR i.e. partial anomalous pulmonary venous return is a rare or uncommon type of congenital heart defect found in children and adults both.