The mitral valve in hypertrophic cardiomyopathy: it's a long story.

Hypertrophic cardiomyopathy (HCM) has evoked both fascination and controversy since its first modern description 50 years ago.1 Originally described as “functional aortic subvalvar stenosis” by Brock, the majority of articles about HCM in the ensuing first decade emanated from observations made in the operating room or in the cardiac catheterization laboratory.1 The actual cause of left ventricular outflow tract (LVOT) obstruction in patients with this condition had not yet been clarified. Ironically, the mechanisms of LVOT obstruction in HCM were only elucidated several years after surgery was first performed in these patients. In fact, an early report by Morrow described the septal myotomy procedure as surgical treatment for HCM and proposed that the myotomy interfered with the sphincter-like muscular contraction ring in the LVOT.1