Gender Differences in the ST Segment - Effect of Androgen-Deprivation Therapy and Possible Role of Testosterone -

Abstract

ST-segment elevation in a structurally normal heart is observed in Brugada- and early repolarization syndrome. The incidence of both syndromes is much higher in males than females. Clinical and basic studies suggest that testosterone plays an important role in ventricular repolarization. Standard surface 12-lead electrocardiograms recorded in 640 healthy subjects were studied (310 males, 330 females ranging in age from 5 to 89 years) (Study 1). The 3 ST levels (ST-J, -M, and -E) were measured in leads V(2) and V(5), which are representative of the right and left ventricles, respectively. The effect of androgen-deprivation therapy on the ST segment was also evaluated in 21 prostate cancer patients (Study 2). In both leads, the 3 ST levels were significantly higher in adult males than females (P<0.0001) due to a marked increase after puberty in males. As their age increased, males manifested a gradual reduction in the ST level in both leads; in females, there was a reduction in lead V(5) only. In both sexes, all 3 ST levels were significantly higher in lead V(2) than V(5) (P<0.0001). Androgen-deprivation therapy significantly decreased all 3 ST segments in both leads. Significant age- and gender differences in the ST segment in healthy adults were found, suggesting that testosterone modulates the early phase of ventricular repolarization.