Glossary for Adult Congenital Heart Disease, P—P

palliation, palliative operation

A procedure carried out for the purpose of relieving symptoms or ameliorating some of the adverse effects of an anomaly, which does not address the fundamental anatomic/physiologic disturbance. Contrasts with "repair" or "reparative operation."

PAPVC

Partial anomalous pulmonary venous connection. See also anomalous pulmonary venous connection.

parachute mitral valve

A mitral valve abnormality in which all chordae tendineae of the mitral valve, which may be shortened and thickened, insert in a single, abnormal papillary muscle, usually causing mitral stenosis. The parachute mitral valve may be part of the Shone complex. See also Shone complex.

partial A-V septal defect

See atrio-ventricular septal defect.

patent ductus arteriosus (PDA)

A ductus that fails to undergo normal closure in the early post-natal period. syn. persistently patent ductus arteriosus, persistent arterial duct.

patent foramen ovale (PFO)

Failure of anatomic fusion of the valve of the foramen ovale with the limbus of the fossa ovalis that normally occurs when left atrial pressure exceeds right atrial pressure after birth. There is no structural deficiency of tissue of the atrial septum. The foramen is functionally closed as long as left atrial pressure exceeds right atrial pressure, but can reopen if right atrial pressure rises. PFO is found in up to 35% of the adult population in pathological studies. The lower and variable prevalence reported in clinical series depends on the techniques used to find it. syn. probe-patent foramen ovale, PFO.

pentalogy of Fallot

Tetralogy of Fallot with, in addition, an ASD or PFO. See also tetralogy of Fallot.

perimembranous VSD

See ventricular septal defect.

persistent left superior vena cava (LSVC)

Persistence of the left anterior cardinal vein (which normally obliterates during embryogenesis) results in persistent left superior vena cava. LSVC drains via the coronary sinus to the right atrium in more than 90% of patients; rarely, it may directly drain to the left atrium in association with other congenital heart defects (e.g., isomerism). Its prevalence is up to 0.5% in the general population, and higher in patients with congenital heart disease.

PFO

See patent foramen ovale.

phlebotomy

A palliative procedure involving withdrawal of whole blood (usually in up to 500 mL increments) which may be offered to patients with cyanotic CHD and secondary erythrocytosis who are experiencing hyperviscosity symptoms. Concomitant volume replacement is usually indicated.

pink tetralogy of Fallot

See tetralogy of Fallot.

polycythemia vera

A neoplastic transformation of all blood cell lines (erythrocyte, leukocyte, and platelet) associated with increased numbers of cells in the peripheral blood. Contrast with secondary erythrocytosis as seen in cyanotic heart disease. See also erythrocytosis.

polysplenia syndrome

See isomerism, and right isomerism.

Potts shunt

A palliative operation for the purpose of increasing pulmonary blood flow, hence systemic oxygen saturation. The procedure involves creating a small communication between a pulmonary artery and the ipsilateral descending thoracic aorta. Often complicated by the development of pulmonary vascular obstructive disease if too large, or acquired stenosis or atresia of the pulmonary artery if distortion occurs. (Potts WJ et al. Anastomosis of aorta to pulmonary artery: certain types of congenital heart disease. JAMA 1946;132:627-631.)

PPH

Primary pulmonary hypertension. See also pulmonary hypertension.

probe-patent foramen ovale

See patent foramen ovale.

protein-losing enteropathy (PLE)

A complication seen following the Fontan operation in which protein is lost via the gut, resulting in ascites, peripheral oedema, pleural and pericardial effusions. It is of unknown cause, though exacerbated by high systemic venous pressure. If serum protein and albumin are low, increased alpha-1 antitrypsin in the stool supports the diagnosis of PLE.

protrusio acetabulae

Abnormal displacement of the head of the femur within the acetabulum. A radiological finding useful in the diagnosis of Marfan syndrome.

pseudotruncus arteriosus

Pulmonary atresia with a VSD, biventricular aorta, and pulmonary blood flow provided by systemic to pulmonary collaterals. This anatomic arrangement had previously been called "truncus arteriosus type IV" but is morphogenetically a different lesion from truncus arteriosus. In pseudotruncus, the single vessel arising from the ventricles is an aorta with an aortic valve, not a truncus with a truncal valve, and pulmonary blood flow derives from aorto-pulmonary collateral arteries, not from anomalously connected true pulmonary arteries.

pulmonary artery banding

Surgically created stenosis of the main pulmonary artery performed as a palliative procedure to protect the lungs against high blood flow and pressure when definitive correction of the underlying anomaly is not immediately advisable, e.g. in the setting of a non-restrictive VSD.

pulmonary artery sling

Anomalous origin of the left pulmonary artery from the right pulmonary artery, such that it loops around the trachea. It may be associated with complete cartilaginous rings in the distal trachea and tracheal stenosis. It may occur as an isolated entity or in association with other congenital heart defects.

pulmonary atresia

An imperforate pulmonary valve. When associated with a VSD (variant of tetralogy of Fallot), pulmonary blood flow arises from aorto-pulmonary collaterals, and systemic venous return exits the right heart via the VSD. When associated with intact interventricular septum, pulmonary artery blood supply is via a patent ductus arteriosus, and systemic venous return exits the right heart via an obligatory ASD.

pulmonary hypertension

Elevated pulmonary arterial pressure. A common method to define the severity of pulmonary hypertension is the pulmonary/aortic systolic pressure ratio:

Severity	Ratio
mild	>0.3, <0.6
moderate	>0.6, <0.9
severe	>0.9 (Eisenmenger syndrome).