Background: Arteriovenous malformations rarely cause congestive heart failure. Pregnancy may in theory trigger heart failure associated with congenital arteriovenous malformations leading to secondary pulmonary hypertension, but no cases have been reported proving that condition.
Methods and results: We report a 23-year-old pregnant woman at 36 + 5 weeks of gestation requiring urgent medical care because of shortness of breath. High-output heart failure was suspected, and a congenital arteriovenous malformation on the right scapular region was considered as the possible origin. The patient required urgent caesarean delivery because of ongoing cardiac failure, which improved soon after delivery. Postpartum angiography of the right subclavian artery revealed an arteriovenous malformation on the deltoid region with venous drainage through the subclavian vein and increased flow to the superior cava vein and right atrium.
Conclusion: A high index of suspicion of arteriovenous malformations should be maintained in pregnant women with cutaneous vascular malformation-like lesions, if symptoms of heart failure are present.
Keywords: Pregnancy; arteriovenous malformations; heart failure; high cardiac output.