Here we report the first infantile case of restrictive cardiomyopathy caused by a de novo mutation of the cardiac troponin T gene. The patient presented with an apparent life-threatening event. She developed malignant arrhythmias and hemodynamic instability, requiring initial rescue support with extracorporeal membrane oxygenation, and subsequently underwent insertion of a biventricular assist device (VAD). She successfully received an orthotopic heart transplant 172 days after VAD implantation.