Recombinant t-PA in Myocardial Ischemia After Switch Operation A. Tzifa, 2 U. Joashi, 1 Z. Slavik 1 1 Department of Paediatric Intensive Care Unit, Royal Brompton Hospital, London, United Kingdom 2 Department of Congenital Heart Disease, Guy’s & St Thomas’ Hospital, London, United Kingdom Abstract. A well-recognized complication of the anatomic correction (arterial switch operation) of transposition of the great arteries is obstruction of the translocated coronary arteries. Myocardial re- perfusion has previously been achieved by surgical revascularization or percutaneous balloon angio- plasty. We report the case of a 3-month-old infant who suffered myocardial infarction 11 weeks after the arterial switch operation, in whom myocardial re- perfusion was established following infusion of re- combinant tissue-type plasminogen activator (AlteplaseÒ). Keywords: Transposition of great arteries — Switch operation — Myocardial ischemia — Recombinant tissue plasminogen activator Introduction Since the early 1980s the arterial switch operation has become the procedure of choice for treatment of transposition of the great arteries. Although the perioperative mortality is nowadays low in most in- stitutions, obstruction of the translocated coronary arteries has been found to be responsible for most deaths and a substantial number of reoperations [2, 9]. Balloon angioplasty and surgical revascularization have been used in the management of coronary artery ischemia after the arterial switch operation in selected patients [1, 4, 10]. We report the case of a 3-month-old infant who suffered acute myocardial infarction 11 weeks after undergoing the arterial switch operation. Intravenous administration of recombinant tissue-type plasmino- gen activator (AlteplaseÒ) was attempted to restore myocardial perfusion. To our knowledge this is the first report on the successful use of recombinant tis- sue-type plasminogen activator for acute myocardial ischemia in an infant following the arterial switch operation. Case Report Following an uneventful pregnancy, the patient was born by spontaneous vaginal delivery at term, with a birth weight of 2.9 kg. He became cyanosed at 24 h of age and an echocardiogram re- vealed transposition of the great arteries with restrictive interatrial communication. He underwent balloon atrial septostomy followed by anatomic correction (arterial switch operation) at the age of 3 days. The right and left coronary arteries arose in close proximity from the posterior sinus adjacent to the commissure between the posterior and the left anterior sinus. They were transferred une- ventfully, and no intraoperative or postoperative ischemia was noted. His postoperative recovery was uneventful apart form transient episodes of supraventricular and nodal tachycardia. He was discharged home on the 10 th postoperative day. The patient represented at the age of 3 months with a 1-day- long history of poor feeding, lethargy, and poor urine output. On admission he was pale, with cold extremities, dyspneic, and tach- ycardic with hepatomegaly. Echocardiography revealed a dilated and poorly contracting left ventricle (end-diastolic dimension 24 mm, shortening fraction 15%) with paradoxical interventricular septal motion. Cardiac catheterization and angiography demon- strated occlusion of the left anterior descending artery, proximally stenosed circumflex artery, and proximally kinked right coronary artery (Fig. 1). Left ventricular systolic function was poor and left ventricular end-diastolic pressure was measured at 20 mmHg. Following catheterization, he received intravenous streptok- inase, as distal pulses in the leg used for vascular access were compromised. During the infusion there was a marked improve- ment in the left ventricular size (end-diastolic dimension 17 mm) and systolic function (shortening fraction 31%) on echocardiogram within 24 h. Streptokinase was discontinued following the full re- turn of his pedal pulses. His left ventricular function progressively deteriorated despite intravenous inotropic support with adrenaline and dobutamine, and 3 days later the shortening fraction had fallen again to 15% (Table 1). At that time he suffered cardiac arrest. Serum levels of cardiac enzymes were elevated and compatible with ongoing myocardial Correspondence to: A. Tzifa, email: aphrodite.tzifa@gsh.sthames. nhs.uk Pediatr Cardiol 25:417–420, 2004 DOI: 10.1007/s00246-003-0473-8