Table 1.

Diagnostic criteria for idiopathic dilated cardiomyopathy.

Criterion
Left ventricular ejection fraction <50%
Left ventricular enlargement (echo-derived left ventricular end-diastolic dimension ≥95th percentile for gender/height)35
Exclusion of all of the following at the time of primary DCM diagnosis:
Coronary artery disease (CAD) causing ischemic cardiomyopathy (>50% narrowing, any major epicardial coronary artery; clinical testing is indicated to exclude CAD routinely in (1) males >40 years or females >45 years without risk factors and (2) males or females >30 years with risk factors)
Primary valvular disease
Cardiotoxic drug exposure, including Adriamycin and other cancer chemotherapeutics
Other forms of cardiomyopathy (e.g., hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, restrictive cardiomyopathy, Chagas cardiomyopathy)
Congenital/structural heart disease
Sarcoid
Amyloid
Iron overload
Other active multisystem disease that may plausibly cause DCM (e.g., hypereosinophilic syndrome, cardiac involvement with connective tissue disease, Loeffler’s endocarditis, endomyocardial fibrosis)
Severe and untreated or untreatable hypertension*
Exclusion beyond a reasonable doubt of all other detectable causes of cardiomyopathy (other than genetic) at the time of primary DCM diagnosis using a rigorous clinical standard congruent with an expert approach rendered by a board-certified heart failure/transplant cardiologist

DCM = Dilated cardiomyopathy.

^*Severe hypertension is defined as systolic blood pressures routinely >180 mm Hg and/or diastolic blood pressures >120 mm Hg. Untreated hypertension is an individual receiving no medications, and untreatable hypertension is an individual with severe hypertension persisting despite multidrug regimens and/or associated with other multisystem disease (e.g., scleroderma, other vasculitides, etc).