When patients present with non ischemic dilated cardiomyopathy (DCM) they are often labeled as idiopathic. In some cases “viral myocarditis”, all too often a waste basket, becomes the default diagnosis. Underappreciated causes of cardiomyopathy was the subject of a recent article in Cardiology in Review.
When confronted with a patient with “idiopathic” DCM how often do you consider the following diagnoses?
Iron overload cardiomyopathy. This can present as either a restrictive or a dilated cardiomyopathy, and may result from hereditary hemochromatosis or various secondary iron overload syndromes
Acromegalic cardiomyopathy presents with left ventricular hypertrophy and/or systolic dysfunction and responds to octreotide.
Thyrotoxic cardiomyopathy may be mediated by a combination of chronic tachycardia, autoimmune damage and the direct effects of thyroid hormone excess.
Chronic tachycardia induced cardiomyopathy may be the most reversible of those listed and has been discussed previously here.
Amyloid cardiomyopathy carries a poor prognosis, but survival is improved with treatment of the underlying serum protein disorder.
The cardiomyopathy of Fabry’s disease may respond to enzyme replacement.
Peripartum cardiomyopathy and takotsubo cardiomyopathy were also mentioned. These are underappreciated disorders although clinical circumstances usually suggest their presence.