Electrocardiographic Patterns of Ventricular Arrhythmias in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

pathology affecting multiple sites of the right ventricle. However the predictive value of this finding is not 100% accurate. Early in the disease of ARVD/C one may see a single form of VT. There has also been a report of multiple forms of VT seen in an idiopathic VT, but the diagnosis in these rare instances must be carefully scrutinized. Niroomand et al. (2002) performed electrophysiology studies in 56 patients with ventricular arrhythmias, based on idiopathic RVOT-VT in 41 and ARVD/C in 15. The presence of more than one type of VT was seen in 75% of the ARVD group compared with 0% in the idiopathic RVOT-VT group, p < 0.0001). The electrophysiology study was also helpful in differentiating the two groups, as inducibility of VT by programmed electrical stimulation with ventricular extrastimuli was seen in 93% of the ARVD/C group compared with only 3% of the RVOT-VT group, p < 0.0001. Fragmented diastolic potentials during ventricular arrhythmia was seen in 93% of the RVOT-VT group compared to 0% in the RVOT-VT group, p < 0.0001. O’Donnell et al. (2003) performed electrophysiology studies in 50 patients, with 33 RVOT-VT and 17 patients having ARVD/C. The presence of more than one type of VT morphology was seen in 71% of the ARVD/C group and 0% in the RVOT-VT group, p < 0.01. Kazmierczak et al. (1998) in the mid 1990s evaluated ECG characteristics in 15 patients with repetitive monomorphic VT (RMVT) of RV origin compared with 12 ARVD cases. One of the 15 cases of RMVT had multiple VT patterns, although the exact number and type were not described. This was the same study that showed baseline anterior T wave changes in 20% of the RVOT-VT group. This observation is at variance with most reports.