Hemi-pericardial agenesis causing myocardial ischaemia in a pregnant woman: a case report.

Background: Pericardial agenesis is one of the rarest cardiac anomalies, often asymptomatic, but, in some cases, causes chest symptoms and, in worst cases, fatal complication. We experienced a case of a pregnant woman with myocardial ischaemia due to a pericardial agenesis. Case summary: A 26-year-old woman who was 14 weeks pregnant visited our hospital complaining of chest pain in the left lateral decubitus position. Although she carefully avoided lying on her left side, chest pain suddenly developed when she was in a supine position at 34 weeks pregnant. An electrocardiogram taken at that time revealed ischaemic changes, implying compression of the coronary vessels. As continuation of the pregnancy would thus be difficult, a caesarean section was successfully performed. A year after delivery, cardiac surgery was performed. The intraoperative findings revealed that the left pericardium was absent, and an edge of the right pericardium was located on the inferior surface of the heart. It was suspected that the myocardial ischaemia was attributable to compression of the coronary artery by this edge. During surgery, this edge was removed. Discussion: In the present case, a patient with a previously asymptomatic hemi-pericardial agenesis was at risk of developing fatal myocardial ischaemia due to pregnancy. Women who lack pericardia require special attention during pregnancy.