Evolution of dilated cardiomyopathy from hypertrophic obstructive cardiomyopathy: a case report

A 20-year-old woman whose echocardiograms showed a rare evolution from hypertrophic to dilated cardiomyopathy during a nine year observation period is described. This patient was initially diagnosed as having hypertrophic obstructive cardiomyopathy (HOCM) at the age of 12 years. Her echocardiogram showed marked thickening of the interventricular septum (IVS) and left ventricular posterior wall (LVPW), asymmetric septal hypertrophy (ASH) and systolic anterior motion of the mitral valve (SAM). Chest radiography revealed a prominent left ventricular border and a cardiothoracic ratio of 0.52. At 18 years of age she experienced onset of palpitation during the 16th week of pregnancy. Her echocardiogram recorded in June 1980 revealed a thickened IVS and LVPW with resolution of the SAM and of the narrow cavity. At 20 years of age she became pregnant again and was admitted to our hospital for the third time at 24 weeks gestation. On admission her blood pressure was 122/60 and her pulse was 56, and moist rales were audible over both lung fields. Peripheral edema was noted. Chest radiography revealed moderate cardiomegaly, a cardiothoracic ratio of 0.66, and congestion of the pulmonary vasculature. An echocardiogram showed thinning of the IVS and LVPW with hypokinesis and dilatation of the cavity compatible with dilated cardiomyopathy (DCM). She delivered a boy on July 15th 1982 at 32 weeks gestation following which she developed marked congestive heart failure. She expired one month later. A chest radiograph made one day before death revealed marked cardiomegaly, a cardiothoracic ratio of 0.76, prominent pulmonary vasculature and a pleural effusion. Autopsy was refused; therefore the terminal DCM-like features were not clarified pathologically. However, the slow progression from HOCM to HCM during eight years and then rapid progression from HCM to DCM during four months was most impressive.