Hypertrophic cardiomyopathy simulating an infiltrative myocardial disease.

Congestive heart failure developed in a patient with low electrocardiographic QRS voltages, diffuse thickening of the septum and free cardiac wall, and a reduction in left ventricular internal diameter, which suggested an infiltrative heart muscle disease. Histological examination at necropsy showed hypertrophic cardiomyopathy with symmetrical left ventricular hypertrophy. Myocardial disarray of type 1A disorganisation was extensive and equally distributed in the ventricular septum and the left anterior and left posterior ventricular free walls. Severe fibrosis (40%) was also present and may have been a possible cause of the electrocardiographic abnormalities as well as of the lack of ventricular dilatation.