Maneuvers and Mitral Regurgitation
The louder a murmur becomes during a manoeuvre depends on how that manoeuvre changes blood flow through the heart. For mitral regurgitation (MR), blood leaks backwards from the left ventricle (LV) into the left atrium (LA) during systole. Anything that increases the amount of blood in the LV or increases the pressure the LV must pump against generally increases the amount of regurgitation and makes the murmur louder. In MR: During ventricular contraction (systole), the mitral valve does not close properly. Blood flows: Forward → aorta Backward → left atrium The classic murmur is a holosystolic (pansystolic) blowing murmur heard at the apex and often radiating to the axilla. The intensity of the murmur depends on: How much blood is leaking backwards. How fast the blood is leaking. Preload is the amount of ventricular filling before contraction. Clinically, think: More venous return → more blood enters LV → higher preload. Imagine: LV normally fills with 100 mL. With increased preload, L