Despite optimization with dofetilide and metoprolol, he was readmitted with recurrent atrial arrhythmias and cardiogenic shock, secondary to probable amiodarone-induced thyrotoxicosis, requiring extracorporeal membrane oxygenation. His clinical course involved multisystem complications, prolonged hospitalization, and disease progression, with no recovery in systolic function despite control of his arrhythmia burden.Intensivists should be cognizant of multi-system complications that can arise when treating refractory cardiac arrhythmias, especially in those with concomitant genetic conditions.