Dilated Cardiomyopathy With Hypothyroidism: A Case Report And Literature Review

Objective: To investigate clinical characteristics, diagnosis and treatment of dilated cardiomyopathy with hypothyroidism.Methods: A case report about a patient with a long history of dilated cardiomyopathy and hypothyroidism is presented, and related literatures are reviewed, from which a few beneficial experiences of diagnosis and treatment are obtained.History: A 63-year-old woman presented with progressive dyspnea, bilateral lower extremity edema and excessive sweating since 2000. She was diagnosed with dilated cardiomyopathy, heart failure and type 2 diabetes in 2010. In 2014, the thyroid examination showed that she had Hashimoto thyroiditis and hypothyroidism, then she was treated with a small dose of levothyroxine for a short time. Despite of using furosemide(40-80mg/d), spironolactone(20-40mg/d), metoprolol(50mg/d), digoxin(0.125-0.25mg/d) for a long time and receiving cardiac resynchronization therapy, the symptom of heart failure continued to deteriorate, and the weight sustained at 80 kg. In January 2015, she presented to the emergency room with heart failure of New York Heart Association(NYHA) functional class â…£.Thyroid function test showed elevated serum levels of thyroid stimulating hormone(105.253uIU/ml) and decreased serum levels of free T4(0.37ng/dl). Chest X-ray imaging showed cardiomegaly. Transthoracic echocardiography showed markedly dilated four chambers, thin ventricular wall thickness, severely depressed cardiac systolic function and a little pericardial effusion. Blood biochemical examination showed elevated creatinase, abnormal liver and kidney function.Intervention and outcome: The patient was treated with diuretic, beta blocker, levothyroxine, etc. She attained euthyroid status within 2 months of levothyroxine therapy. When metoprolol was gradually added to 150mg/d, the excessive sweating stopped. During 1-year follow up, her weight went down from 80 kg to 60 kg, her signs and symptoms, such as dyspnea, peripheral edema were relieved, in the end, the dose of furosemide was gradually reduced to 20-40 mg for every three days. Chest X-ray imaging showed normalized heart size. Transthoracic echocardiography showed decrease of the enlarged heart, especially retraction of left atrium, right atrium and right ventricle, improvement of left ventricular systolic and diastolic function, and absorption of pericardial effusion. Blood biochemical examination showed normalized creatinase, liver and kidney function.Conclusion: Hypothyroidism may cause a series of change of cardiac structure and function. It also can aggravate dilated cardiomyopathy and heart failure. With hormone replacement therapy, cardiac remodeling can be partly reversed and cardiac function can be improved. Excessive sweating and cardiac remodeling in patients with heart failure are associated with over excitation of sympathetic nerve. They can be relieved by beta blockers, but it need to reach the target dose or maximum tolerated dose. Hypothyroidism are often ignored in patients with heart failure. Patients with heart failure should check thyroid function.