Incidence of quadricuspid pulmonary valves at postmortem examination.

Quadricuspid pulmonic valve is a rare congenital abnormality and because of its difficult non-invasive assessment, it is usually discovered incidentally at autopsies (reported prevalence in post-mortem specimens ranges from 1 in 400 to 1 in 2000). Unlike a bicuspid pulmonary valve, it rarely presents with clinical complications, such as valvular insufficiency or stenosis. Abnormal function is rarely reported in cases that are not associated with other congenital heart disease. With increased sophistication of imaging coincidental quadricuspid valves autopsy studies are important to understand the anatomical consequences of this finding. Our case series identified 21 QPV cases from the Victorian Institute of Forensic Medicine, Melbourne and St George's University of London, Department of Cardiovascular Pathology. Cases were identified through local database searches and review of autopsy/cardiac examination reports over a 20-year period. Available photographs were also systematically examined. Fifteen cases had causes of death with no direct causality to cardiac valvular pathology alone. Six cases were considered unascertained or similar (sudden arrhythmic death syndrome and sudden unexpected death in epilepsy). The presence of QPV in these instances were uncertain but thought to be unlikely contributory to death, due to the absence of pulmonary valvular complications.