Selective and non-selective right bundle pacing for the diagnosis of bundle branch reentry ventricular tachycardia

AIMS AND BACKGROUND: Bundle branch reentry ventricular tachycardia (BBRVT) can be seen in patients with conduction disease. In this report, we describe the use of conduction system pacing for its diagnosis. METHODS AND RESULTS: BBRVT was induced in two patients with infra-nodal conduction disease. Bundle branch reentry ventricular tachycardia with a left bundle branch block morphology was observed in the first patient (type A), whereas the second patient had a right bundle branch block morphology (type C). The diagnosis of BBRVT was confirmed in both patients by ventriculo-atrial dissociation, and the interdependence of the conduction system and the ventricular tachycardia cycle length variations. Selective and non-selective RB pacing was observed in the two patients during apical right ventricular pacing for entrainment of BBRVT with evidence of manifest entrainment with non-selective RB capture in the first patient, and concealed entrainment by selective RB capture in the second patient. Other criteria for entrainment including a short post-pacing interval at the right bundle pacing site were noted. CONCLUSION: Right bundle pacing is feasible in patients with BBRVT and may be a helpful manoeuver for the diagnosis of BBRVT.