Transvenous biopsy of the<unk>  ventricle can be highly specific for ARVD, but it has low sensitivity.  False positives include other conditions with fatty infiltration of the ventricle, such as chronic alcohol abuse and Duchenne/Becker muscular dystrophy.
False negatives are common, however, because the disease progresses typically from the epicardium to the endocardium (with the biopsy sample coming from the endocardium), and the segmental nature of the disease.  Also, due to the paper-thin<unk><unk>  free wall that is common in this disease process, most biopsy samples are taken from the<unk>  septum, which is commonly not involved in the disease process.
A biopsy sample that is consistent with ARVD would have > 3% fat, >40% fibrous tissue, and <45% myocytes.
Arrhythmogenic right ventricular dysplasia endomyocardial biopsy
Myocarditis endomyocardial biopsy
Dilated cardiomyopathy MRI
Noncompaction cardiomyopathy echocardiography
Cardiac amyloidosis nuclear cardiac scans
Cardiac amyloidosis cardiac biopsy
Noncompaction cardiomyopathy MRI
Hypertrophic cardiomyopathy MRI