Cushing syndrome cardiomyopathy: an unusual manifestation of small‐cell lung cancer

Cushing syndrome is a rare cause of dilated cardiomyopathy and heart failure with reduced ejection fraction. Cases describing this association are scarce. We describe a patient presenting with acute heart failure, new cardiomyopathy, refractory hypokalaemia, severe hyperglycaemia, and uncontrolled hypertension who was found to have hypercortisolism secondary to an ectopic adrenocorticotropic hormone‐secreting primary lung neoplasm. This case highlights the effects of hypercortisolism on the myocardium. The finding of a non‐dilated cardiomyopathy in this case is unique because the majority of previously reported Cushing syndrome cardiomyopathy cases have described left ventricular dilatation or significant left ventricular hypertrophy. In addition, small‐cell lung cancer with adrenocorticotropic hormone production causing Cushing syndrome cardiomyopathy is rare.