Objective: The study aimed to calculate the QT distance on ECG in patients with severe preeclampsia and to investigate the effect of magnesium sulfate given in treatment on QT dispersion (QTd).

Materials and Methods: Thirty pregnant women with severe preeclampsia as study group and 30 pregnant women of similar age and gestational age without any systemic diseases and pregnancy-related complications as control group were included in the study. Standard 12-channel ECGs of all patients were recorded. Corrected QT (QTc) interval was calculated.

Results: The QTc dispersion of severe preeclamptic patients was 49.35±3.33 msec. The QTc dispersion of the control group was 31.39±0.91 msec. There was a statistically significant difference between the preeclampsia and control groups (p<0.001). The QTc dispersion decreased by 33.43±1.13 msec in severely preeclamptic pregnant women after magnesium sulfate (p<0.001).

Conclusions: Severe preeclampsia significantly increases QTc dispersion. Administration of magnesium sulfate in treatment positively affects QTd.