Anomalous insertion of the papillary muscle causing left ventricular outflow obstruction: visualization by real-time three-dimensional echocardiography.

Anomalous insertion of the papillary muscle (PM)/chordae tendineae is a rare but important cause of dynamic left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic cardiomyopathy or cardiac amyloidosis. These anomalies are often challenging to diagnose with 2-D Echo, yet accurate diagnosis is critical in determining whether to proceed with an extended septal myectomy instead of a standard septal myectomy for relief. We report two cases of anomalous insertion of the PM causing LVOT obstruction with diagnosis facilitated by real-time 3-D echocardiograms.