We describe a woman who presented in her third trimester of pregnancy with progressive dyspnea. Physical exam showed a hyperdynamic right ventricular impulse and a widely split fixed S2. Echocardiography showed moderately enlarged right sided chambers and linear insertion of the atrioventricular valves. This echocardiographic finding is typically consistent with a partial atrioventricular septal defect (AVSD). However further imaging with cardiac MRI revealed a large ostium secundum atrial septal defect (ASD), with a pulmonary to-systemic flow ratio of 2.4. This appears to be the first documented case in the literature of a secundum ASD presenting with linear insertion of the atrioventricular valves. In conclusion, we describe an unusual case of secundum atrial septal defect in pregnancy presenting with dyspnea and linear insertion of the atrioventricular valves.

Cardiovascular Disease (CVD) is the leading cause of death globally in women and men, respectively 34.6% and 31.4% in 2019. The incidence of CVD is higher in men, yet worse prognosis and higher mortality after an acute cardiovascular event are seen in women. Advances in diagnosis and treatment have led to a reduction in mortality rates in both sexes over the last decades.