Antithyroid therapy, including methimazole, hydrocortisone, and Lugol's iodine, reversed severe storm-induced cardiomyopathy (EF improved from 15-20% to 60-65%) in a 72-year-old man.
Case Report (n=1)
Thyroid storm can present as refractory atrial fibrillation and cardiogenic shock, and early antithyroid therapy can reverse the severe cardiomyopathy.
Abstract Introduction Thyroid storm is a rare, life-threatening manifestation of thyrotoxicosis characterized by severe end-organ dysfunction precipitated by excessive thyroid hormone activity. Its incidence is estimated at 0.2-0.7 cases per 100,000 persons annually, but mortality remains high (8%-25%) despite modern intensive care. The hypermetabolic state can precipitate cardiovascular collapse through tachyarrhythmias, high-output failure, or, paradoxically, acute systolic dysfunction. Recognition is often delayed because presentation overlaps with sepsis or cardiogenic shock. We report a case of thyroid storm masquerading as refractory atrial fibrillation with rapid ventricular response (RVR) and acute heart failure, highlighting diagnostic challenges and the critical impact of early endocrine evaluation. Case Presentation A 72-year-old man with atrial fibrillation on apixaban and prostate cancer in remission presented with dyspnea, obtundation, and atrial fibrillation with RVR complicated by shock. He required emergent intubation and multiple cardioversions with no rhythm control despite amiodarone and beta-blockade. Laboratory studies showed leukocytosis, severe transaminitis, lactic acidosis, and acute kidney injury. Echocardiography revealed new systolic dysfunction (EF 15-20%) compared to 60-65% a year prior. Chest CT demonstrated mild pulmonary edema with consolidations; sputum cultures grew MRSA, prompting antibiotics for concurrent pneumonia. Despite maximal hemodynamic support including CRRT and inotropes, he remained unstable. Thyroid studies later revealed TSH 0.012 µIU/mL, FT4 1.58 ng/dL, and FT3 1.5 pg/mL; Burch-Wartofsky Point Scale was 80, confirming thyroid storm. Methimazole (chosen over PTU due to hepatic injury), hydrocortisone, and Lugol’s iodine were initiated. Over eight days, thyroid indices normalized, atrial fibrillation with RVR resolved, and his EF recovered to 60-65%. Multiorgan function improved, and the patient regained consciousness but was unable to make a complete neurological recovery; hence, the family eventually decided to opt for comfort measures. Discussion This case underscores thyroid storm’s protean presentation and potential to mimic mixed cardiogenic-septic shock. Acute reversible cardiomyopathy in this setting likely reflects catecholamine toxicity and metabolic myocardial stunning. While the Burch-Wartofsky Point Scale remains a valuable bedside tool, routine thyroid testing in unexplained shock or refractory tachyarrhythmia can expedite diagnosis. Early institution of antithyroid therapy, beta-blockade, iodine, and corticosteroids can reverse cardiovascular dysfunction and reduce mortality. Our patient’s dramatic cardiac recovery emphasizes that even severe storm-induced cardiomyopathy may be reversible with timely therapy. This case reinforces the need for heightened suspicion of thyroid storm in patients with refractory atrial fibrillation, shock, or unexplained acute heart failure. This abstract is funded by: None
Maqsood et al. (Fri,) conducted a case report in Thyroid storm (n=1). Methimazole, hydrocortisone, and Lugol's iodine was evaluated. Antithyroid therapy, including methimazole, hydrocortisone, and Lugol's iodine, reversed severe storm-induced cardiomyopathy (EF improved from 15-20% to 60-65%) in a 72-year-old man.