Prevalence of arrhythmias in patients with idiopathic dilated cardiomyopathy.

A total of 105 patients with idiopathic dilated cardiomyopathy (IDCM) underwent Holter monitoring. The prevalence of arrhythmias was as follows: ventricular premature beats (VPB) 100%, including complex VPB 58.1%, short runs of ventricular tachycardia (VT) 25.7%, A-VB or BBB 46.7%, atrial arrhythmias 38.1%, sinus node dysfunction 6.6%, ST-T change 38.1%. The incidence of ventricular arrhythmia (VA) was not related to severity of cardiac dysfunction (NYHA), duration of illness and sex. The most common arrhythmia was VA, the second one was heart block and atrial arrhythmia. Serum norepinephrine and epinephrine levels were 743.4 +/- 252.5 and 688.0 +/- 452.4 pg/ml, respectively, which were higher than those in control group (P < 0.01). Isoproterenol sensitivity test (ICD25) 8.43 +/- 11.21 micrograms, was also much higher than that in control group (P < 0.01). Average H-V interval was 69.4 +/- 13.3 msec in HBE. Eight patients died. Two died of congestive heart failure (class II-IV), and six cases were diagnosed as sudden cardiac death resulting from VT and VF.