Postpartum QT Prolongation in a Long QT Syndrome Type 1 Patient

Female LQTS patients are at high risk for arrhythmogenic events during the postpartum period due to hormonal influence on cardiac repolarization.

We observed an LQT1 patient with previous cardiac events during pregnancy and 3 weeks postpartum. We obtained ECG recordings and quantified sex hormone levels.

Peak pregnancy: QTc: 420 ± 7 ms, Estradiol: 24.18 ng/mL, Progesterone: 218 ng/mL. Seven days postpartum: QTc prolongation to 455 ± 5 ms. 22 days postpartum: QTc: 452 ± 5, Estradiol: 0.013 ng/mL, Progesterone: 0.25 ng/mL.

Estradiol and Progesterone decline rapidly after birth, correlating to QTc prolongation and elevated risk for arrhythmogenic events. Therefore, modification of pharmacological or device therapy may be considered.