The effect of heart failure on heart rate variability in patients after myocardial infarction treated with thrombolysis

The aim of this study was to estimate if low left ventricle ejection fraction (EF) influence the HRV in patients with acute myocardial infarction (AMI) treated with thrombolysis. 160 consecutive patients with AMI treated with thrombolysis were enrolled in the study. Echocardiography and 24-hour ECG recordings with analysis of several time-domain indexes of HRV: (SDNN, SDNNI, SDANNI, rMSSD and pNN50) were obtained at discharge (12 day of hospitalization). The 24-hour ECG recordings were repeated after 6 months of follow-up. On the basis of ejection fraction patients were divided into two groups: I - EF > 40% and II pound 40%. We found that time domain indexes of HRV were higher in group I than in group II at day 12 of hospitalization. There was statistical significant difference between groups in SDNN, SDNNI and pNN50 at discharge. We didn't find statistical significant difference between groups 6 months after AMI.