Spiked Helmet Sign in the Early Post-Heart Transplantation Period: A Dramatic STEMI Mimic in a Structurally Normal Donor Heart.

A 36-year-old woman with severe dilated cardiomyopathy (LVEF 14%, NYHA IV) underwent heart transplantation. Postoperatively, she developed subarachnoid hemorrhage and septic shock. The ECG revealed a spiked helmet sign (SHS) pattern, with repolarization abnormalities and QT prolongation. Despite transient clinical improvement and resolution of the ECG changes after intensive support, the patient died due to infectious complications. This case highlights the occurrence of SHS in the early posttransplant period in a structurally normal donor heart, a previously unreported presentation, reinforcing its extracardiac origin and association with critical illness and poor prognosis.