A case of partial congenital pericardial defect presenting as acute coronary syndrome.

Congenital pericardial defects are rare and asymptomatic for both partial and complete defects. However, some patients can experience syncope, arrhythmia, and chest pain. When a patient experiences a symptom, it may be caused by herniation and dynamic compression or torsion of a heart structure including the coronary arteries. Diagnosis of a congenital pericardial defect may be difficult, especially in old patients with concomitant coronary artery disease. The clinical importance of congenital pericardial defect has not been stressed and congenital pericardial defects are regarded as benign, but in this case, pericardial defect was responsible for myocardial ischemia. The authors report a case of partial congenital pericardial defect causing herniation and dynamic compression of the coronary arteries, presenting as an acute coronary syndrome in an old man, with an emphasis on the unique features of the coronary angiogram that support the diagnosis of partial pericardial defects.