A ventricular septal defect (VSD) is a hole in the ventricular septum, the wall dividing the left and right ventricles of the heart. It is a common congenital A ventricular septal defect (VSD) is a hole in the ventricular septum, the wall dividing the left and right ventricles of the heart. It is a common congenital heart defect, although restrictive muscular VSDs are not true pathological defects; they are typically just a delayed closure of the ventricular septum. They have an extremely high prevalence in newborns. The extent of the opening may vary f Pansystolic (Holosystolic) murmur along lower left sternal border (depending upon the size of the defect) +/- palpable thrill (palpable turbulence of blood flow). Heart sounds are normal. Larger VSDs may cause a parasternal heave, a displaced apex beat (the palpable heartbeat moves laterally over time, as the heart enlarges). An infant with a large VSD will fail to thrive and become sweaty and tachypnoeic (breathe faster) with feeds. The restrictive ventricular septal defects (smaller defects) are associated with a louder murmur and more palpable thrill (grade IV murmur). Larger defects may eventually be associated with pulmonary hypertension due to the increased blood flow. Over time this may lead to an Eisenmenger's syndrome the original VSD operating with a left-to-right shunt, now becomes a right-to-left shunt because of the increased pressures in the pulmonary vascular bed.