Maternal electrocardiographic changes in the peripartum period.

Continuous electrocardiographic monitoring was performed in 20 term parturients during labor, vaginal delivery, and recovery. Mean duration of monitoring was 13.37 h. Sinus tachycardia was seen in all parturients (mean maximum heart rate=138); in 8 patients (40%), maximum heart rate was not attained until 0.5-5 h after delivery. Eight patients exhibited premature ventricular contractions or supraventricular tachycardia. ST-segment depression was noted in 3 patients (15%); in all 3, this was concurrent with maximum heart rate, was not associated with any symptoms, and occurred in the post-partum period.