What are heart sounds and murmurs?
Heart sounds are generated from the closure of the valves. There are 2 normal heart sounds. One is generated from closure of the mitral and tricuspid valves when the heart contracts and is called S1. The second heart sound is generated from the closure of the aortic and pulmonic valves when the heart relaxes and is called S2. Abnormal heart sounds can be generated in the setting of heart failure (S3) or from a very stiff ventricle, such as in the setting of long-standing high blood pressure or heart attacks (S4). Heart murmurs can range from normal (or physiologic) in the setting of normal valvular function to abnormal (or pathologic), such as in the setting of a severe leak (regurgitation) or narrowing (stenosis) in the valves. When a valve is narrowed, the blood ejected through it generates a high velocity jet and turbulence, which causes the murmur. Also, if a valve leaks, a high jet of blood flows through the leaky valve, generating a murmur. Murmurs have various characteristics an
