Sachin Kumar Amruthlal Jain MD , Kashyap Patel MD , Patrick Alexander MD and Shukri David MD
The prevalence of congestive heart failure (CHF) is increasing. A rare cause of CHF is hyperthyroidism. It can affect the cardiovascular system manifesting from decreased systemic vascular resistance, increased left ventricular contractility, and sinus tachycardia to atrial fibrillation. Less than 0.5% is due to tachycardia- mediated mechanism. Heart failure in the absence of underlying cardiac disease or arrhythmia is thought to reflect a rate related cardiomyopathy that most likely resolves with treatment. Our patient is a 56 year-old African American female with past medical history of subacute thyroiditis and medication noncompliance presented to ER with a two-week history of increasing exertional dyspnea and bilateral leg edema. She was hypertensive, tachycardic and tachypnic. Examination revealed bibasilar rales and 2+ pitting edema. Laboratory data revealed a TSH of 0.01 and free T4 of 3.3, consistent with hyperthyroidism. Two-dimensional echocardiogram revealed biventricular enlargement and ejection fraction of 25%. Thyroid uptake scan demonstrated significant homogenous uptake in both lobes consistent with Grave’s disease. Six months ago her thyroid scan showed 5% uptake with hyperthyroid state, consistent with subacute thyroiditis. She was treated with beta-blockers and diuretics with profound symptomatic improvement. Definitive therapy consisted of maintaining euthyroid state. This case illustrates an unusual presentation of Grave’s disease with CHF without atrial fibrillation. Typically, thyrotoxicosis presents as high output failure. However, as time progresses it can cause low output failure. Dilated cardiomyopathy is an unusual manifestation of hyperthyroidism with unclear etiology. Early diagnosis is of utmost importance as some patients with hyperthyroidism may have a reversible form of dilated cardiomyopathy
