Endocrine Abstracts

JOINT2821

Introduction: Hyperthyroidism is a systemic disorder with significant cardiovascular implications, including arrhythmias and structural heart changes. We report a case of a 27-year-old male with untreated hyperthyroidism presenting with thyroid storm and severe cardiovascular complications.

Case Description: A 27year-old male presented to the emergency room with worsening asthenia, palpitations, myalgia, diarrhea, and fever (39-40°C) over the past week. He was diagnosed with hyperthyroidism in 2019 but had not been taking any medications nor attending follow-up appointments. His clinical history included 25 kg weight loss, episodic palpitations, sweating, anxiety, and extremity tremor since 2019. On admission, he was alert, reactive, with marked exophthalmos and goiter. His blood pressure was 90/73 mmHg, heart rate of 180 bpm, corresponding to atrial fibrillation. Laboratory findings indicated severe hyperthyroidism: TSH <0.01 mUI/l (RV 0.27-4.20), T3 577 ng/dl (RV 80-200), fT4 6.03 ng/dl (RV 0.93-1.70); hepatocellular injury (ALT 167 UI/l, AST 126 UI/l, total bilirubin 1.7 mg/dl), mild systemic inflammation (CRP 3.47 mg/dl) and positive TRABs (17.7 UI/l). A diagnosis of thyroid storm was made (85 points on the Burch-Wartofsky Point Scale), and the patient was admitted to the intensive care unit, where treatment with propylthiouracil, hydrocortisone, potassium iodide, and propranolol was initiated. However, due to worsening hepatic cytolysis, therapy was switched to methimazole. A transthoracic echocardiogram revealed a severely dilated left atrium and severe mitral regurgitation, attributed to annular dilation, posterior leaflet hypomobility, and pseudo prolapse of the anterior leaflet (EROA 0.52 cm², regurgitant volume 63 mL). Right ventricular systolic function was impaired, and a mobile hypoechoic mass was noted near the superior vena cava, raising suspicion of thrombus formation. Anticoagulation therapy was initiated, and additional studies were performed to rule out other potential etiologies or complications. No other significant findings were identified. Heart rate control was challenging, necessitating additional digoxin before stabilizing with beta-blockers after euthyroidism was achieved. Follow-up echocardiography showed an improvement in mitral regurgitation severity from severe to mild-moderate.

Discussion: This case underscores the profound effects of hyperthyroidism on cardiovascular function, emphasizing the necessity of early diagnosis and intervention to avert life-threatening complications. The improvement in structural heart changes, such as mitral regurgitation, after achieving euthyroidism highlights the dynamic cardiovascular impact of thyroid dysfunction and reinforces the need for comprehensive endocrine and cardiac management.

Conclusion: Thyroid dysfunction can significantly impact cardiac structure and function. Early recognition and treatment of hyperthyroidism are crucial to prevent cardiovascular deterioration and improve patient outcomes.