Thyroid storm induced congestive heart failure

Background: Uncontrolled thyrotoxicosis is known to lead to a state of prolonged tachycardia that may then progress to the onset of reversible congestive heart failure. Case: The patient is a 36-year-old female with a history of Asthma, bilateral ovarian benign cysts, chronic goiter presented due to persistent cough, wheezing, and shortness of breath for about two days duration, echocardiogram had been done for respiratory failure, showing reduced ejection fraction, diastolic dysfunction, and dilated cardiomyopathy. She was subsequently admitted to the MICU for treatment of respiratory failure due to asthma exacerbation. Then began feeling symptoms of anxiety, palpitations, tremulousness, facial flushing. Evaluation of her labs showed elevated T3 at >650, elevated T4 at 22.6, with diminished TSH level at 0.01. The patient was diagnosed with thyroid storm in consideration of lab values with clinical features. TSI was ordered, which returned at 674. Endocrinology was consulted; the patient added a history of tremors for three weeks and weight loss of about 5 pounds over several months, with symptoms of generalized anxiety and dysphagia; she also reported diarrhea in the past weeks. She refers to a family history of goiter in her aunt. The recommendation from an endocrinology perspective was to obtain TSI level and ESR, continue methimazole. The patient was clinically stabilized, discharged on medications for heart failure and methimazole. However, she developed a rash on methimazole, and this was stopped. The patient went for radioactive iodine ablation, and a repeat echo showed an improvement of her ejection fraction. The patient was asymptomatic at a one-year cardiology follow-up, and cardiology medications were discontinued. Conclusion: Hyperthyroidism is a known cause of congestive heart failure secondary to tachycardia-induced cardiomyopathy if untreated. After the proper treatment, this heart failure can be reversed if tachycardia is controlled.