Objectives: Study several parameters of cardiac arrhythmia and heart rate variability in elderly patients with dilated cardiomyopathy (DCM), investigate the relationship and correlation between these parameters with NYHA functional heart failure class, EF, LVDd in elderly patients with DCM. Subjects and methods: 30 patients with DCM undergone treatment in Cardiovascular Department. Their ages were ≥ 60. These patients were diagnosed heart failure according to Framingham criteria and DCM according to WHO/ISFC criteria. 24-hour Holter ECG was the method used to analyse cardiac arrhythmia as well as heart rate variability (HRV). These parameters were compared with those considered normal of 81 people. Results: Sinus bradycardia accounted for 6.7%, sinus tachycardia 96.7%, sinus pause 13.3%, premature ventricular contraction 76.7%, supraventricular tachycardia 6.7%, ventricular tachycardia 40%. Lown’s classification: Lown’s class I undertook 46.7%, Lown’s class II 53.3%, Lown’s class III 23.3%, Lown’s class IVA 63.3%, Lown’s class IVB 36.7%, V 6.7%, p < 0.01. HRV indices: SDNN: 57.93 ± 16.99 ms, SDANN: 47.33 ± 16.69 ms, SDNNidx: 31.83 ± 11.00 ms, rMSSD: 19.87 ± 4.39 ms, pNN50: 3.67 ± 2.88%, the parameters acquired from case group were lower than those of control group with statistical difference (p < 0.0001). HRV decreased in proportion to NYHA functional heart failure class and LVEF. There was proportional correlation between LVEF with SDNN (r=0.77, p < 0.01), SDANN (r=0.76, p<0.01), SDNNidx (r=0.66, p<0.01), rMSSD (r=0.58, p<0.01), and pNN50 (r=0.69, p<0.01). Conclusion: 24-hour Holter ECG was valuable in detecting cardiac arrhythmia and HRV in elderly patients with DCM. This method also contributed to the following up, treatment and prognosis of this disease. Keywords: Arrhythmia, heart rate variability, dilated cardiomyopathy, elderly
