C100. Torsades de Pointes (Polymorphic VT) as a Manifestation in Hypothyroid Patient’s: A Case Report

Hypothyroidism is a common endocrine disorder with varying abnormalities including cardiac manifestations consisting of structural, functional, and electrical conduction problems especially in severe cases. Torsades de pointes (TdP) is a very rare initial presentation in a patient with hypothyroidism. We report a patient with severe hypothyroidism manifest with life-threatening arrhythmias.

A 48-year-old man who underwent emergency resuscitation suffering from cardiac arrest. On admission, the patient collapsed and was unresponsive. Electrocardiography (ECG) showed QT interval prolongation, and polymorphic ventricular tachycardia (TdP). Laboratory test revealed marked hypokalemia (potassium concentration of 2.6 mmol per liter) and unexpected severe hypothyroid (Free T4 (FT4) was <0.07 [normal 0.93-1.71] μg/dl; thyroid-stimulating hormone (TSH) was >60.0 [normal 0.27-4.20] mIU/mL). Temporary cardiac pacing was placed for managing specific arrhythmias. The patient was also treated with levothyroxine 100 μg per day, and the underlying electrolyte disturbance was corrected. Treatment with levothyroxine was continued in outpatient clinic. ECG and thyroid tests were returned to normal limit within six weeks.

Clinicians need to highlight that TdP is relatively rare in hypothyroidism. Early diagnosis and prompt management were needed due to potential fatal cardiac manifestation if left untreated. All patients with overt hypothyroidism with TSH >10 mIU/L should be treated. Administration of levothyroxine is a mandatory treatment and should be monitored carefully and safely to eliminate arrhythmias.