We report a 14-month-old male with hypoplastic left heart syndrome, mitral stenosis, and aortic stenosis with native aortic root thrombus. He developed a wide complex ventricular tachycardia and ST-segment elevation myocardial infarction with troponin I levels peaking at 388 ng/mL. He was treated safely with systemic alteplase with a resolution of his regional wall motion abnormality 18 hours later.