tokens: In the absence of histological criteria , which it is difficult to demand in view of the variability of results and potential dangers of endomyocardial biopsy involving such thin and fragile ventricular walls , the diagnosis of ACRV is based upon the concomitant existence of : ( 1 ) electrophysiological criteria : ventricular arrhythmias , in particular sustained monomorphous VT , with the particular feature of a very high degree of sensitivity to adrenergic stimulation ( exercise ) , the existence of late potentials on the high amplification ECG , a highly specific sign , though unfortunately of poor sensitivity in localized froms , those which are most difficult to identify ( 2 ) ; segmentary morphological and kinetic RV abnormalities , most often resulting in localized akinetic or dyskinetic parietal vaulting , with stasis " in situ " .