Heart Rate Variability in Stable Angina Patients without History of Myocardial Infarction

ABSTRACT

BACKGROUND AND OBJECTIVES: Heart rate variability(HRV) reflects the autonomic integration of heart. There were many reports that HRV in patients with myocardial infarction or heart failure is an independent prognostic factor to predict fatal arrhythmia and sudden cardiac death. But, the role of HRV is still controversial in stable angina patients without history of myocardial infarction. In this study, we tried to compare HRV indices between stable angina patients and normal subjects. MATERIALS AND METHODS: Twenty-one stable anginal patients without history of myocardial infarction (mean age 57 +/- 2 years) and twenty-one relatively healthy persons without history of coronary heart disease (mean age 53 +/- 2 years) were included in the study and underwent 24-hour ambulatory ECG monitoring. In patients group, all underwent coronary angiography after 24-hour ambulatory ECG monitoring. HRV was analyzed over the whole 24 hours, using time and frequency domain parameters, according to time phases and coronary angiographic severity. RESULTS: There were no significant differences in age, sex and cardiovascular risk factors, except hypertension (p=.001) between two groups. HRV indices such as rMSSD, pNN50, LF, HF, LFnorm and HFnorm were significantly decreased (p<0.05) in patients group. But the angiographic severity of coronary arteries did not show any significant effect on the HRV indices in patients group. CONCLUSIONS: We observed significantly reduced HRV indices in patients with stable angina without history of myocardial infarction.