The pulmonic valve is one of two valves that allow blood to leave the heart via the arteries. It is a one-way valve, meaning that blood cannot flow back into the heart through it. The valve is opened by the increased blood pressure of the ventricular systole (contraction of the muscular tissue), pushing blood out of the heart and into the artery. It closes when the pressure drops inside the heart. It is located in the right ventricle of the heart. The pulmonic valve opens into the pulmonary artery. The frequency of this cycle depends upon the heart rate. Pulmonary stenosis is a condition where the blood flow out of the heart is obstructed at the pulmonic valve. The most common cause of this is congenital heart disease, although rheumatic heart disease and a malignant carcinoid tumor can also initiate the problem. The condition is treated by surgical repair or replacement of the pulmonic valve.