American Journal of Medical Case Reports
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American Journal of Medical Case Reports. 2019, 7(10), 228-229
DOI: 10.12691/ajmcr-7-10-2
Open AccessCase Report

T3 Thyrotoxicosis Induced Dilated Cardiomyopathy

David Bassilly1, 2, , Michael Figart1, 2, Krithika Suresh1, 2, Mohamed Saad Eldin1, 2 and Samuel Massoud1, 2

1Department of Internal Medicine, Temple University, Philadelphia, PA, USA

2Department of Internal Medicine, Conemaugh Memorial Medical Center, Johnstown, PA, USA

Pub. Date: July 26, 2019

Cite this paper:
David Bassilly, Michael Figart, Krithika Suresh, Mohamed Saad Eldin and Samuel Massoud. T3 Thyrotoxicosis Induced Dilated Cardiomyopathy. American Journal of Medical Case Reports. 2019; 7(10):228-229. doi: 10.12691/ajmcr-7-10-2


The most recognizable features of hyperthyroidism are those that result from the effects of triiodothyronine (T3) on the heart and cardiovascular system: decreased systemic vascular resistance and increased resting heart rate, left ventricular contractility, blood volume, and cardiac output. Although these measures of cardiac performance are enhanced in hyperthyroidism, the finding of clinical cardiac failure can be somewhat paradoxical. About 6% of thyrotoxic individuals develop symptoms of heart failure, but less than 1% develop dilated -cardiomyopathy with impaired left ventricular systolic function. Heart failure resulting from thyrotoxicosis is due to a tachycardia-mediated mechanism leading to an increased level of cytosolic calcium during diastole with reduced ventricular contractility and diastolic dysfunction, often with tricuspid regurgitation. Pulmonary artery hypertension in thyrotoxicosis is gaining awareness as a cause of isolated right-sided heart failure. In both cases, older individuals are more likely to be affected. Treatment needs to be directed at management of the acute cardiovascular complications, control of the heart rate, and thyroid-specific therapy to restore a euthyroid state that will lead to resolution of the signs and symptoms of heart failure.

T3 thyrotoxicosis heart failure AFib

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