Aortopulmonary window presenting with severe pulmonary hypertension during pregnancy: A case report

Aortopulmonary window defect is an extremely rare congenital cardiac defect characterised by a communication between the ascending aorta and the pulmonary trunk. A 37-year-old woman at 36 weeks of gestation of her second pregnancy presented with pre-term, pre-labour rupture of membranes. She was noted to have hypoxia on room air, and a bedside transthoracic echocardiogram revealed pulmonary hypertension. Urgent CT pulmonary angiogram showed no evidence of pulmonary embolism, but her HRCT Chest revealed consolidation in the upper zone of the left lung. She underwent emergency lower segment caesarean section under spinal anaesthesia. Following administration of the spinal anaesthetic, she developed hypotension and oxygen desaturation leading to emergency intubation and mechanical ventilation. A formal 2D transthoracic echocardiogram done afterwards showed an aortopulmonary window with a 3 cm defect complicated by severe pulmonary hypertension, together with right-to-left shunting, demonstrating Eisenmenger physiology. The hypoxia and hypotension were postulated to be due to spinal anaesthesia causing reduction of systemic vascular resistance and worsening of right-to-left shunting. She was managed with pulmonary vasodilators, diuretics and intravenous antibiotics. She was discharged after a lengthy ICU stay, with long-term home oxygen therapy.