Case summary: We report a case of maternal bradycardia in a 34 year old primigravida patient with preeclampsia associated with haemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome at 30+4 gestation. The woman’s blood pressure, liver function tests and platelets initially improved following betamethasone therapy. Forty-eight hours following the second dose of betamethasone the patient complained of severe epigastric pain accompanied by abrupt fall in pulse rate from 85 to 40 beats per minute (bpm), worsening of hypertension, liver enzymes and platelet count. Electrocardiography revealed sinus bradycardia but was otherwise normal. Serum potassium, thyroid function and high sensitivity troponin were also unremarkable. The woman proceeded to have an urgent caesarean section delivering a live male of birthweight 1248g. Postpartum, in recovery, the woman’s pulse had risen to 60 bpm and epigastric pain resolved. Transthoracic echocardiography was normal.
Discussion: Preeclampsia is a pregnancy specific syndrome which can affect multiple organs, including alterations in cardiovascular haemodynamics. Transient maternal bradycardia with preeclampsia and HELLP syndrome has been previously described in several case studies [1–4]. The pathophysiology of this is not understood, but postulated mechanisms include impaired cardiopulmonary baroreflex, increased vagal tone due to elevated levels of proinflammatory cytokines, and disturbance in the autonomic control of heart rate.[5]. Maternal bradycardia may be a sign of severe preeclampsia.
Reference
[1] A. Hosokawa, T. Umazume, T. Yamada, H. Minakami, Maternal bradycardia occurring prior to onset of HELLP syndrome in a woman with pre-eclampsia, BMJ Case Rep. 2017 (2017). https://doi.org/10.1136/bcr-2016-217964.
[2] N. Angsubhakorn, D. Benditt, Relative Sinus Bradycardia: An Unexpected Finding in Preeclampsia With Acute Pulmonary Edema, Cureus. (2021). https://doi.org/10.7759/cureus.13262.