Hypertrophic obstructive cardiomyopathy with a basal septal thickness of 16 mm or less: clinical characteristics and surgical results.

Symptomatic patients with hypertrophic obstructive cardiomyopathy and mild septal hypertrophy may have a higher prevalence of mitral subvalvular abnormalities. Mitral subvalvular management during myectomy can achieve outstanding results for these patients.