EP study in BBRVT

Twelve surface ECG leads and intracardiac recordings from the ablation catheter (Carto D: placed at the location of the distal His recording), a decapolar His catheter (H1,2 to H9,10), and the RV catheter are shown during BBRVT. There are spontaneous cycle length variations in the tachycardia. Changes in the H-H interval predict the subsequent changes in the V-V interval, suggesting the dependence of the tachycardia on the His Purkinje network. This finding strongly supports the diagnosis of BBRVT.