Cardiomyopathies characterized by evidence of resistance to left ventricular inflow

Restrictive cardiomyopathy characterized by evidence of left ventricular inflow obstruction was studied in four cases—one child and three adults. In three of the cases, including the child, there was pathologic evidence of hypertrophic cardiomyopathy with asymmetric septal hypertrophy. In the fourth case, no cardiac disease was identified as the anatomic basis for the inflow restriction. This latter case broadens the concept of restrictive cardiomyopathies.