Cardiac Murmurs Made Simple

Murmurs are extra heart sounds that are produced as a result of turbulent blood flow that is sufficient to produce audible noise.Heart murmurs are most frequently organized by timing, intosystolic heart murmurs and diastolic heart murmurs. 

Systolic heart murmurs are heart murmurs heard during systole.Valvular aortic stenosis can produce a harsh, or even a musical murmur over the right second intercostal space which radiates into the neck over the two carotid arteries. The most common cause of Aortic Stenosis is calcified valves due to aging followed by congenital bicuspid aortic valves.Mitral valve prolapse is the most common cause of late systolic murmurs. It can be heard best over the apex of the heart, usually preceded by clicks. The most common cause of mitral valve prolapse is "floppy" valve syndrome. If the prolapse becomes severe enough, mitral regurgitation may occur.Any maneuver that increases left ventricular volume — such as squatting, elevation of legs, hand grip, and phenylephrine — can delay the onset of clicks, shorten murmur duration, and increase murmur intensity.

Holosystolic (pansystolic) murmurs are heard through out the cardiac cycle.They are usually due to regurgitation in cases such as mitral regurgitation, tricuspid regurgitation, or ventricular septal defect (VSD).

Diastolic heart murmurs are heart murmurs heard during diastole.The murmur in Aortic regurgitation is low intensity, high-pitched, best heard over the left sternal border or over the right second intercostal space, especially if the patient leans forward and holds breath in full expiration. The radiation is typically toward the apex. The configuration is usually decrescendo and has a blowing character. Mitral Stenosis murmur has a rumbling character and is best heard with the bell of the stethoscope in the apex with the patient in the lateral decubitus position. It usually starts with an opening snap.

by

Akshaya Srikanth

Pharm.D Intern

India