Cardiac arrest as the initial presentation of thyrotoxicosis in a young woman

Ventricular fibrillation and cardiac arrest, even in patients without structural heart disease, can be a presentation of thyroid storm. Coronary vasospasm represents a potential mechanism linking thyrotoxicosis to malignant ventricular arrhythmias. Prompt recognition and restoration of euthyroidism are essential for reversing hemodynamic instability and preventing recurrence. Nonadherence to antithyroid therapy remains a major preventable trigger of thyroid storm.