A ventricular septal defect (VSD) is a hole in the ventricular septum, the muscular wall separating the left and right ventricles of the heart. VSDs are the most common congenital heart defect, occurring in approximately 2 to 5 per 1,000 live births. They may also develop as a rare but serious complication following a myocardial infarction (post-infarction VSD).
The clinical significance of a VSD depends on its size. Because blood pressure in the left ventricle is substantially higher than in the right, when a VSD is present, blood shunts from left to right with each heartbeat. This increases blood flow through the pulmonary circulation and volume load on the left heart. Small VSDs often close spontaneously in childhood and cause no symptoms. Large VSDs can cause breathlessness, poor growth, and heart failure in infancy and, if untreated for years, can lead to irreversible pulmonary hypertension (Eisenmenger syndrome).
Diagnosis is by echocardiography. Small, asymptomatic VSDs do not require treatment beyond monitoring. Symptomatic or haemodynamically significant VSDs are repaired by open heart surgery (closure with a patch) or by transcatheter device closure, which is possible for some muscular VSDs.
Post-infarction VSD is a rare but life-threatening complication occurring within days to weeks of a large myocardial infarction, when ischaemic necrosis of the interventricular septum creates an acute VSD. This causes sudden haemodynamic deterioration and requires urgent surgical or transcatheter repair.
« Back to Glossary Index