Ventricular unipolar potential in radiofrequency catheter ablation of idiopathic non-reentrant ventricular outflow tachycardia

We conducted this Study to verify the efficacy of ventricular Unipolar potential (V-uni) for ablation of idiopathic non-reentrant ventricular tachycardia (idio-VT). The morphology of V-uni at the Successful and unsuccessful sites was analyzed in 27 patients with idio-VT [20 with right Ventricular Outflow tachycardia (RVOVT) and 7 with left ventricular Outflow tachycardia (LVOVT)]. The usefulness Of V-Uni was compared with a pacemapping method and the V-QRS interval. The incidence of QS-pattern V-Uni at the Successful and best unsuccessful sites were 100 versus 25% (P = 0.000005) in RVOVT and 86 versus 29% (P = 0.10) in LVOVT. The pacemapping scores at the successful and best unsuccessful sites were 11.5/12 versus 11.2/12; NS in RVOVT, and 11.2/12 versus 11.1/12: NS in LVOVT. The mean V-QRS interval at the Successful and the best unsuccessful sites were 22.5 +/- 3.8 Versus 21.6 +/- 3.4 msec; NS in RVOVT, 15.1 +/- 3.2 versus 12.5 +/- 3.3 msec; NS in LVOVT. The sensitivity (sen) and specificity (spe) of QS-pattern V-uni to determine the Optimum target sites were 1.0 and 0.89 in RVOVT and 0.86 and 0.83 in LVOVT. respectively. In the ablation of idio-VT, QS-pattern V-uni is simply and Visually identifiable, is very useful, and Should be given a high priority when determining the OptirnUrn target site.