The Effects of Sublingual Estradiol on Left Ventricular Function at Rest and Exercise in Postmenopausal Women

Abstract

To evaluate the acute hemodynamic effects of 4 mg estradiol given sublingually. Rest and exercise echocardiographies were performed prior to estradiol administration. Then, another set of tests was done post-dose: rest examination at 1 h post-dose, isometric exercise at 65 min post-dose, and dynamic exercise at 100 min post-dose. The administration of 4 mg sublingual estradiol to 24 postmenopausal women (aged 48-58 years) was followed 60 min post-dose by a surge in mean estradiol serum levels (1759 +/- 704 pg/ml). At rest a slight drop in systolic and diastolic blood pressure was measured after estrogen ingestion: 132 +/- 24 mm Hg versus 127 +/- 21 mm Hg, p < 0.05; 83 +/- 11 mm Hg versus 78 +/- 10 mm Hg, p < 0.02. There were no changes in resting heart rate, double product, or vascular resistance. The left heart cavities became smaller: the left atrium diameter decreased from 33.7 +/- 4 mm to 32.3 +/- 4 mm, p < 0.01; the end-systolic diameter decreased from 24.9 +/- 3 mm to 23.6 +/- 4 mm, p < 0.01; the end-diastolic diameter decreased from 44.5 +/- 4 mm to 42.7 +/- 4 mm, p < 0.01. The peak aortic blood flow velocity fell from 120 +/- 19 cm/s to 116 +/- 22 cm/s (p < 0.05), and the flow velocity integral fell from 26.3 +/- 4 cm to 24.9 +/- 5 cm (p < 0.01); the cardiac output underwent a small change, with borderline significance: 7 +/- 2 L/min versus 6.7 +/- 2 L/min, p = 0.06. Only minor changes in the hemodynamic and echocardiographic parameters were recorded after estrogen for both isometric and dynamic exercises. Analyses were also made for two subgroups: 13 normotensive women were compared with 11 hypertensive women. The post-estrogen decreases in resting blood pressure and in peak blood velocity were observed only in the hypertensive subjects, whereas the changes in heart dimensions and in flow velocity integral were the same in both subgroups. Sublingual estradiol was associated with acute hemodynamic alterations mainly at rest but also after exercise.