Question

A heart murmur is the audible noise generated when blood is allowed to flow through a heart valve when it shouldn’t. Based on your knowledge of the cardiac cycle, which valve(s) would you predict to cause a murmur during diastole, and which valve(s) would you predict to cause a murmur during systole? Be sure to explain your answer.

Answer 1

Heart murmur during systole is caused by stenosis of pulmonic or aortic valves (have a crescendo-descrescendo character ) due to the ejection of blood through narrowed orifice. Regurgitation of mitral and tricuspid valves would also lead to a systolic murmur (high intensity through out the systole).

Heart murmur during diastole is caused by regurgitation of aortic or pulmonary valves during which the blood starts flowing backward through the diseased valve due to a drop in the ventricular pressure during relaxation. Stenosis of mitral and tricuspid valve would also result in diastolic murmur. (descrescendo murmur)