Climacteric women often suffer from vasomotor symptoms. These symptoms are thought to be related to an imbalance of autonomic control of the cardiovascular system and are effectively controlled with hormonal replacement therapy. Heart rate variability (HRV) reflects the autonomic integration of the cardiovascular system. In this study, we attempted to compare the HRV indices of postmenopausal women before and after hormonal replacement therapy.

Eighteen patients with postmenopausal syndrome (mean age:53±4 years) received estrogen and/or progesterone replacement therapy. They underwent 24-hour ambulatory electrocardiographic monitoring at baseline and after the early period of therapy (mean:112±19 days) and eleven patients underwent the examination after the later period of therapy (mean 213±23 days). HRV was analyzed over a full 24-hour period, using time and frequency domain parameters.

No statistically significant HRV change was observed during the early period of therapy. However, during the later therpy period , HRV indices such as rMSSD[from 27.6 to 31.3 (msec)], HF[from 4.8 to 5.05 ln (ms2)], LF/HF ratio (from 1.17 to 1.12) were significantly changed (p value<0.05).

HRV was significantly changed in postmenopausal women during the later period of hormonal replacement therapy.