Bradycardia in the setting of postpartum preeclampsia and influenza A: A case report

Postpartum bradycardia is a rare clinical finding, with limited guidance regarding its evaluation and management. Prior literature suggests that postpartum bradycardia is most commonly associated with preeclampsia, underlying cardiac disease, medication effects, or neuraxial anesthesia. In patients with preeclampsia, management may be particularly challenging, as magnesium sulfate-used for seizure prophylaxis-is theorized to exacerbate bradycardia. This report concerns the case of a 33-year-old woman (G3P3003) with an otherwise uncomplicated pregnancy and cesarean delivery who was diagnosed with Influenza A on postpartum day 1 and treated with oseltamivir. She was readmitted on postpartum day 7 with epigastric pain and shortness of breath and was found to have severe sinus bradycardia (heart rate 32-42 beats per minute) and highly elevated blood pressure, consistent with new-onset postpartum preeclampsia with severe features. Cardiac evaluation, including electrocardiography and transthoracic echocardiography, revealed no structural or ischemic abnormalities. The patient was treated with magnesium sulfate for seizure prophylaxis and antihypertensive therapy. Despite persistent bradycardia, she remained hemodynamically stable, and her heart rate gradually normalized over three days without additional intervention. She was discharged in stable condition and remained asymptomatic at follow-up. This case highlights postpartum bradycardia as a potential presenting sign of delayed-onset preeclampsia, even following a normotensive pregnancy. Although magnesium sulfate and recent influenza infection were considered as contributing factors, the clinical course supported preeclampsia as the primary etiology. Postpartum bradycardia is often benign and self-limited; however, thorough evaluation is essential to exclude cardiac pathology and guide appropriate management.