[The electrocardiogram in myocardial diseases].

From 1970 to 1980 75 patients with dilatative, 51 patients with hypertrophic, and 8 patients with restrictive cardiomyopathy (endomyocardial fibrosis) have been investigated. The routine electrocardiogram showed premature ventricular beats in patients with dilatative (53%) and hypertrophic (59%) cardiomyopathy. Atrial fibrillation was observed in 16% of the patients with dilatative and 37% of the patients with restrictive cardiomyopathy. Left axis deviation was seen in dilatative (45%) cardiomyopathy and right axis deviation in restrictive (37%) cardiomyopathy. A left bundle branch block was seen in 33% of the patients with dilatative cardiomyopathy and left ventricular hypertrophy in 55% of the patients with dilatative and 67% of the patients with hypertrophic cardiomyopathy. Left and right atrial hypertrophy was observed in patients with restrictive cardiomyopathy (50%) and left atrial hypertrophy in patients with dilatative cardiomyopathy (40%). It is concluded that the electrocardiogram in patients with dilatative cardiomyopathy is characterized by premature ventricular beats, left ventricular and left atrial hypertrophy and a left bundle branch block. Hypertrophic cardiomyopathy is characterized by left ventricular hypertrophy with negative T-waves and premature ventricular beats, and restrictive cardiomyopathy by atrial fibrillation, right axis deviation and left and right atrial hypertrophy.