Acute myocardial infarction with isolated congenitally corrected transposition of the great arteries.

Congenital cardiac abnormalities diagnosed at the time of acute coronary syndrome are rare. A 43-year-old man presented to the emergency department complaining of recurring, severe chest pain. Subsequent emergent coronary angiography demonstrated unusual coronary anatomy: 1) one small caliber bifurcating vessel originating from the right sinus of Valsalva; 2) one very large vessel arising from the posterior sinus; and 3) no coronary artery from the normal left sinus of Valsalva. The large vessel from the posterior sinus was totally occluded in its midportion and was treated with intravascular ultrasound-guided percutaneous coronary intervention. Further diagnostic workup, including two-dimensional transthoracic echocardiogram and computed tomographic coronary angiography, demonstrated isolated corrected transposition of the great arteries with a dilated systemic ventricle and systolic dysfunction with an ejection fraction of 30%. The patient's clinical course was complicated by recurrent nonsustained ventricular tachycardia, treated with medical therapy and a dual-chamber implantable cardioverter defibrillator. This case is an example of a common clinical presentation with a very uncommon congenital heart disorder. Similar cases may become more frequent as the number of adult congenital heart patients increases in the population.