Effect of ovulation induction on QT dispersion in electrocardiography

To investigate whether ovulation induction resulting in supra-physiological concentration range of ovarian hormones has an effect on interlead ventricular depolarization heterogeneity via QT dispersion measurements. Estrogens influence the duration of cardiac repolarization but there is no significant change in the QT interval duration within the range of physiological estradiol variations. Materials and methods: Included in the study were 40 subjects, in whom ovulation induction was planned, and 20 volunteers. During the study, a 12-lead electrocardiogram of each woman was carried out 3 times: for the first time on day 2-3 of the menstrual cycle (menstrual day), for the second time 36 h after hCG administration (ovulatory day), and for the third time at 6-8 days following ovulation (mid-luteal day). The RR and QT wave distances were measured. The QT interval corrected for heart rate (corrected QT) was calculated for each derivation. The difference between the longest and shortest corrected QT intervals was determined as corrected QT dispersion. Results: No difference was seen in the mean QT and corrected QT interval duration and the maximum corrected QT interval duration between menstrual phases. On the ovulatory day at peak estrogen level, the corrected QT dispersion was found to be lower than on mid-luteal and menstrual day. Conclusion: QT dispersion demonstrates the regional repolarization heterogeneity of the myocardium, which reflects the propensity of ventricular arrhythmia decreases on the ovulatory day of the ovulation induction cycle.