[The electrocardiogram in dilated cardiomyopathy].

The electrocardiogram (ECG) of 80 patients with dilated cardiomyopathy was studied. An abnormal ECG was present in 100% of our patients, and in 25% it was the first sign of the disease. Thirty-eight cases (47.5%) showed left atrial enlargement, 22 (27.5%) prolonged PR interval, 33 (41.2%) left bundle branch block, 15 (18.7%) abnormal Q waves, 9 (11.2%) primary S-T and T changes. There were significant differences in ejection fraction and in left ventricular end-diastolic volume between patients with right bundle branch block (p less than 0.05 and p = 0.05 respectively). Patients were followed for a period of 29.5 +/- 28.8 months (min. 2 days, max. 10 years): during the observation period the ECG showed in 28 cases an increasing left ventricular conduction delay and a leftward shifting of mean QRS axis. Patients with left ventricular conduction delays showed a worse prognosis. ECG in dilated cardiomyopathy is a nonspecific but sensitive tool, which may be related to different degrees of myocardial impairment and may be useful in the definition of a prognostic profile.