日本小児循環器学会雑誌 Pediatric Cardiology and Cardiac Surgery

A 16-year-old male with complete congenital atrioventricular block since 1 year old was treated by epicardial pacemaker lead implantation. At 9 years old, he was diagnosed with supravalvular pulmonary artery stenosis resulting from epicardial pacemaker leads with cardiac strangulation as the possible cause. Transient ST change was seen only in the exercise tolerance test, with no chest pain, indicating that myocardial ischemia was absent. The deterioration status of supravalvular pulmonary artery stenosis was assessed by catheterization. With his arms raised, he was injected with a small amount of contrast media, suddenly, he lost consciousness. Electrocardiography showed ST segment alterations after frequent premature ventricular contractions, followed by junctional bradycardia that rapidly progressed to asystole. Hence, transient ischemia caused by arm raising or frequent premature ventricular contractions and deterioration of the coronary artery compression was suspected. The leads were then removed in an urgent surgery. In conclusion, contrast-enhanced computed tomography should be conducted in patients with cardiac strangulation, and earlier lead exchange should be performed because of the rapid deterioration of myocardial ischemia.