The ECG findings of 112 cases of primary congestive cardiomyopathy were summarized with a peculiarity of tachycardiac ectopic arrythmia

heart block and myocardiac damage. In analysing the frequency of heart block the bundle branch or intracardiac block(53.6%)was more commonly met than that of atrial-ventricular block(18.8%)

while the left bundle branch (25%)together with the fascicular branch block(13.4%)were frequently seen than right bundle branch block(21.4%).The bilaterial bundle branch(9.8%)and trifascicular brabch block(4.5%) were also found

sometimes accomanied with sick sinus syndrome.The above mentioned multiple levels and sites of heart block indicated that the invasion of the cardiomyopathy was very diffuse and severe. The ventricular premature beat was frequent and of multifocus with the opportunity turnned into ventricular tachycardia or fibrillation which might be lead to sudden death as seen in coronary heart disease.