The aim of this study was to analyze the incidence and types of arrhythmia and their relationship with the severity and prognosis of chronic heart failure (CHF) in patients with dilated cardiomyopathy (DCM), and to investigate the therapeutic effect of torasemide versus furosemide on CHF and incidence of arrhythmia. DCM patients with NYHA cardiac function II-IV were continuously monitored using a 24-h dynamic electrocardiogram (Holter), and arrhythmia incidence was analyzed by computer automatic analysis combined with manual assessment. In total, 125 participants were evenly divided into two groups: torasemide group which received 10 mg oral torasemide once daily) and regular anti-heart failure treatment (N=65), and furosemide group which received torasemide (20 mg once daily orally) and regular antiheart failure treatment (N=60). Another 60 normal healthy persons served as the normal control group. Incidence and severity of arrhythmia increased when degree of CHF was elevated. Size of left atrium was related to atrial fibrillation and size of left ventricle was related to malignant arrhythmia. At 3 months after treatment, cardiac function in both groups improved and incidence and severity of arrhythmia in both groups were reduced. However, left ventricular ejection fraction (LVEF) was higher in the torasemide group than in the furosemide group, while incidence of arrhythmia was lower in the torasemide group. Arrhythmias frequently occurred in patients with DCM and HF. Type of cardiac arrhythmia is closely related to ventricular enlargement and cardiac function grade. Torasemide is better for improving cardiac function to reduce arrhythmia and CHF compared to furosemide.