Think outside the “box” Revisiting Heart Failure and Hypothyroidism

Heart failure is one of the most common health problems requiring hospitalization. Usual causes exacerbating HF include cardiomyopathies, coronary heart disease and uncontrolled hypertension. When presented with such a case, while it is important to rule out underlying cardiac causes, one must also think of reasons outside the heart. Hypothyroidism is a common non-cardiac etiology for heart failure, which may be missed especially given its subtle clinical features. We present a 64 year old woman, who presented with heart failure secondary to longstanding hypothyroidism. She developed dilated cardiomyopathy which was not reversible even with thyroxin supplementation and eventually needed an ICD placement. This case highlights the importance of thyroid disorder on heart disease and how on occasion, it can even be permanent.