Murmurs - Pulmonary Stenosis
You are listening to a typical example of the murmur caused by pulmonary valve stenosis. Pulmonary stenosis is an infrequent cause of significant murmurs, and is often a part of congenital disorders, such as tetralogy of Fallot, Williams syndrome, and Noonan syndrome.
The murmur of pulmonary stenosis is heard best in the “pulmonic area”, the second intercostal space along the left sternal border. The murmur can be heard radiating into the neck or the back, has a crescendo-decrescendo shape, and a harsh quality. Because it takes longer for the right ventricle to eject its load of blood through the stenotic valve, the closure of the pulmonary valve is delayed. This widens the slight gap between the closure of the aortic and pulmonary valves in S2 to a noticeable degree, and a significant splitting of S2 can be heard, as is well demonstrated in this audio example. Finally, maneuvers which increase venous filling and blood flow into the right ventricle, such as deep inspiration, will tend to increase the intensity of the murmur.