ARVD is best described as which of the following?

• A. Right Ventricular Myocardium Replaced By Fatty And Fibrotic Tissue
• B. Left Ventricular Hypertrophy
• C. Global Dilatation Of All Chambers
• D. Atrioventricular Conduction Block

Answer: (A)

Arrhythmogenic right ventricular dysplasia/cardiomyopathy is a condition where the right ventricular myocardium is progressively replaced by fibrous and fatty tissue. This fibrofatty replacement weakens the right ventricle, causing regional wall motion abnormalities, dilation, and sometimes aneurysm formation. The scar tissue creates an electrical substrate that promotes reentrant ventricular arrhythmias, often presenting as VT arising from the right ventricle in younger individuals.

This description fits ARVD best because it centers on the structural change in the right ventricle—the myocardium being replaced by fat and fibrous tissue—which is the defining feature. Left ventricular hypertrophy would imply thickened LV walls from pressure or genetic causes; global dilatation of all chambers points to a dilated cardiomyopathy; atrioventricular conduction block is a conduction abnormality, not the characteristic structural pathology of ARVD.