Changes in Heart Rate Variability Measures During Exercise in Patients with Essential Hypertension

The aim of this study was to assess the changes of heart rate variability parameters during exercise in patients with essential hypertension. Seventeen hypertensive patients treated with ACE inhibitors and 19 healthy subjects were evaluated by time domain and frequency domain parameters of heart rate variability. All subjects wcrc studied with exercise treadmill test according to the Bruce protocol. The exercise tests were negative in all subjects. Time domain and frequency domain parameters of heart rate variability were measured for each the 5 -minute segment before and after exercise and during the exercise period . There were no significant differences between the two groups with regard to age, gender, heart rate at rest and maximum, exercise time and METS value. Heart rate variability analysis showed that sympathetic activity was higher in hypertensive patients than in normal subjects at rest period. But, autonomic activity was not different between the two groups during exercise. Key words : Hypertension, heart rate variability, exercise