Papillary muscle insertion directly into the anterior mitral leaflet in hypertrophic cardiomyopathy, its identification and cause of outflow obstruction by cardiac magnetic resonance imaging, and its surgical management.

This case presents an uncommon but important mechanism of muscular left ventricular outflow obstruction in hypertrophic cardiomyopathy due to anomalous and direct papillary muscle insertion into the anterior mitral leaflet, a finding reliably identified clinically by cardiac magnetic resonance imaging. The identification of this left ventricular outflow tract morphology is important before invasive ventricular septal reduction therapy because it dictates a specific surgical strategy. These findings further support the role of cardiac magnetic resonance imaging in the early evaluation of hypertrophic cardiomyopathy patients.