Right Ventricular Tachycardia with Left Bundle Branch Block and Inferior Axis Morphology: Clinical and Arrhythmological Characteristics in 15 Patients

UNLABELLED: Fifteen patients (mean age 30) presenting with right ventricular tachycardia (VT) of the outflow tract type (left bundle branch block with inferior axis morphology), in the absence of obvious organic heart disease, were studied. Seven patients had palpitations, one presyncope and seven were asymptomatic. The echo and/or angiographic findings were normal in 11 patients (73%), suggesting arrhythmogenic right ventricular dysplasia (ARVD) in three (20%) and dubious in one (7%). The VT was sustained in three patients (20%), nonsustained (11 +/- 6 beats) in twelve (80%), inducible during exercise in two out of 15 patients (13%) and with ventricular stimulation in one out of eight (12.5%). Four patients were treated with sotalol, three with Class IC drugs and one with amiodarone. At follow-up of 36 +/- 30 months, only three patients had VT recurrences due to drug withdrawal. IN CONCLUSION: (1) abnormal echo and/or angiographic findings suggested that ARVD was observed in a minority of the patients (22%); (2) the low inducibility of VT and the good response to sotalol suggested a possible mechanism of abnormal automaticity; and (3) at a 3-year follow-up the prognosis appeared to be good in both patients with or without echo-angiographic signs suggestive of right ventricular dysplasia.