If the anterior leaflet prolapses, the MR jet angle is directed:

If the anterior leaflet prolapses, the MR jet angle is directed:

• A. Posteriorly
• B. Anteriorly
• C. Centrally
• D. Inferiorly

Answer: (A)

The direction of the regurgitant jet in mitral regurgitation reflects where the regurgitant orifice sits and how the blood flows back into the left atrium. When the anterior leaflet prolapses, the hole through which blood leaks is toward the front of the mitral valve. The backward flow then tends to travel toward the posterior aspect of the left atrium, so the MR jet is directed posteriorly. This opposite relationship—prolapse of the anterior leaflet yielding a posteriorly directed jet (and vice versa for the posterior leaflet)—is a useful localizing clue on echocardiography.

The direction of the regurgitant jet in mitral regurgitation reflects where the regurgitant orifice sits and how the blood flows back into the left atrium. When the anterior leaflet prolapses, the hole through which blood leaks is toward the front of the mitral valve. The backward flow then tends to travel toward the posterior aspect of the left atrium, so the MR jet is directed posteriorly. This opposite relationship—prolapse of the anterior leaflet yielding a posteriorly directed jet (and vice versa for the posterior leaflet)—is a useful localizing clue on echocardiography.