ARVD is characterized by progressive replacement of the right ventricular myocardium by fibrofatty tissue.
The most common location for this tissue transformation is between the anterior infundibulum, right ventricular apex, and inferior or diaphragmatic aspect of the right ventricle, the so-called “ triangle of dysplasia”.
Dysplasia in this region usually leads to dilatations or aneurysms having paradoxical systolic motion (expansion with systole instead of contraction).
The concealed phase . This phase is characterized by RV changes with or without ventricular arrhythmias. It is mostly seen in young people involved in competitive sports. Sudden death is often the first manifestation.
The second stage of ARVD is overt electrical disorder. The RV undergoes both functional and structural changes, leading to RV arrhythmias or cardiac arrest.
The third phase of ARVD is RV failure. The progression of RV muscle disease leads to RV dysfunction. Left ventricular function is usually spared at this point.