Figure 39m

Anomalous papillary muscle insertion directty into anterior mitraL leaflet (AML) in patient with obstructive HCM.
A. Before myotomy-myectomy:
parasternal Long-axis echocardiogram shows AML in direct continuity with the hypertrophied anomalous anterolateral papillary muscle (APM), which displaced anteriorly within the left ventricular cavity, producing a long area of midcavity muscular contact with the ventricular septum (VS) and outflow obstruction (arrows); tips of the mitral leaflets coapt in the usual position, and typical systolic anterior motion is absent (small arrows).
B. After myotomymyectomy: Long-axis echocardiogram shows extensive muscular resection , extending from base of the septum to beyond the distal margins of the anterior mitral leaflet; nevertheless, a Large area of direct muscular contact remains after operation between papillary muscle and ventricular septum (arrowheads), which is responsible for persistent and marked obstruction to left ventricular outflow. C. Mitral valve specimen excised at operation; a massively hypertrophied anterolateral anomalous papillary muscle (arrow) inserted directly into the body of the anterior leaflet. Ao = aorta; l.A = left atrial; LV = left ventricle.

(From Klues HG et al with permission of the authors ind ippincott William and Wilkins.)