A peak deflection index >0.6 on an inferior lead identified unsuccessful radiofrequency catheter ablation for outflow tract ventricular tachycardia with 80% sensitivity and 90% specificity.
Observational (n=70)
Does a peak deflection index >0.6 predict unsuccessful radiofrequency catheter ablation in patients with outflow tract ventricular tachycardia/ventricular premature contractions?
A peak deflection index >0.6 on the inferior lead with the tallest R wave is a useful ECG predictor of difficult or unsuccessful radiofrequency catheter ablation for outflow tract ventricular arrhythmias, suggesting a deep septal or epicardial origin.
Effect estimate: 80% sensitivity, 90% specificity
p-value: p=0.002
BACKGROUND: An ECG predictor of ablation success has not been determined for difficult cases of outflow tract ventricular tachycardia/ventricular premature contractions (OT-VT/VPC). METHODS AND RESULTS: ECG analysis and radiofrequency catheter ablation (RFCA) were performed in 70 patients with OT-VT/VPC. The peak deflection index (PDI) was determined in the inferior lead presenting the tallest R wave by dividing the time from QRS onset to peak QRS deflection by total QRS duration. In 10 (14%) of the 70 patients, RFCA performed at a septal or epicardial site was unsuccessful (group 1), but was successful in the remaining 60 patients (group 2). Neither activation time (35+/-15 ms vs 40+/-12 ms, P=0.3) nor QRS duration (141+/-19 ms vs 137+/-19 ms, P=0.6) were significantly different between groups 1 and 2. However, PDI was significantly higher in group 1 than in group 2 (0.62+/-0.06 vs 0.55+/-0.06, P=0.002). A PDI >0.6 identified unsuccessful OT-VT/VPC with 80% sensitivity and 90% specificity, and may indicate that the origin of the OT-VT/VPC is deep within the ventricular septum or at an epicardial site. CONCLUSIONS: A PDI >0.6 is more likely to be associated with a higher rate of RFCA failure.
Hachiya et al. (Fri,) conducted a observational in Outflow tract ventricular tachycardia/ventricular premature contractions (OT-VT/VPC) (n=70). Peak deflection index (PDI) on an inferior lead was evaluated on Unsuccessful radiofrequency catheter ablation (80% sensitivity, 90% specificity, p=0.002). A peak deflection index >0.6 on an inferior lead identified unsuccessful radiofrequency catheter ablation for outflow tract ventricular tachycardia with 80% sensitivity and 90% specificity.