The Echocardiographic Assessment of Cardiomyopathy: Diagnosis, Classification and Problems

Two-hundred-and-sixty-three patients with cardiomyopathy were studied by M-mode echocardiography. Measurements of left ventricular cavity size, wall thickness and myocardial contraction were used to classify cardiomyopathy into "congestive" (212 patients) and "hypertrophic" (50 patients) groups; the "hypertrophic" group was further divided into asymmetric septal hypertrophy (37) and symmetric (concentric) mural thickening (13). Using clinical and electrocardiographic information as well as echocardiographic data, the latter group could then be further classified into "concentric infiltrative cardiomyopathy" (9) and "concentric hypertrophic cardiomyopathy" (4). The former either presented with signs of restriction or were known to have systemic amyloidosis; the electrocardiograph showed low voltage and myocardial contraction was impaired in advanced cases. The latter had evidence of severe left ventricular hypertrophy and resembled asymmetric septal hypertrophy clinically. Problems encountered with the echocardiographic diagnosis of congestive cardiography were mainly concerned with proper clinical interpretation of the echocardiographic data whilst technical difficulties in recording the echocardiogram and in interpretation of tracings were a common problem in hypertrophic cardiomyopathy.