Muscular (hypertrophic) subaortic stenosis (hypertrophic obstructive cardiomyopathy): the evidence for true obstruction to left ventricular outflow

Summary The clinical and haemodynamic significance of the subaortic pressure gradient in patients with muscular (hypertrophic) subaortic stenosis (hypertrophic obstructive cardiomyopathy) has long been debated. In this report we summarize the evidence which indicates that true obstruction to left ventricular outflow exists in these patients. Rapid left ventricular ejection, through an outflow tract narrowed by ventricular septal hypertrophy,...