Ventricular septal defect is a type of congenital heart disease, occurring when the ventricles of the heart develop poorly during the embryonic stage, leading to a defect in the ventricular septum. This often results in a left-to-right shunt which affects the efficiency of the heart's function. In severe cases, it can cause a right-to-left shunt. Generally, these conditions do not affect the coronary circulation or cause chest pain in patients. However, some patients may develop endocarditis at the ventricular septum, which sometimes leads to the formation of vegetations on the cardiac valves or blood clots on the abdominal wall. If thrombosis or vegetations occur, there is a possibility of these breaking off. If they enter the coronary arteries, they can cause chest pain. However, such events are extremely rare, with an occurrence rate of less than one in a thousand.