RIGHT-VENTRICULAR DYSPLASIA - RIGHT AND LEFT-VENTRICULAR INVOLVEMENT MORPHOMETRICALLY EVALUATED

Right ventricular dysplasia (RVD) is a cardiac anomaly characterized b y replacement of variable amounts of right ventricular myocardium by a dipose tissue. This condition is believed to be a selective disorder i nvolving extensively the right ventricle, but there are occasional rep orts of concomitant ''minor'' abnormalities of the left ventricle. The object of this report concerns a patient who died after heart transpl antation because of an unsuspected RVD of the donor heart. We present a morphometric study of the heart in order to evaluate the distributio n of the fat on both ventricles and to understand the structural basis of the heart failure. The results show that a large portion of the ri ght ventricle is replaced by fat with a quite homogeneous distribution ; the left ventricle is also largely replaced by adipose tissue that i s primarily localized at the apex and decreases from the apex to the b asis. The remodeling of the heart is attributable to a conspicuous inc rease in volume of the right ventricle associated with a normal number of myocytes that are longer than normal. For these reasons, according to Starling's law, the heart develops congestive failure.