High-Density Mapping in Ventricular Tachycardia Ablation: A PentaRay^® Study

High-density mapping of ventricular tachycardia (VT) with PentaRay^® (Biosense-Webster) provides high resolution with discrimination of local abnormal electrograms and slow conducting channels. We evaluate the feasibility of PentaRay^® to characterize the anatomical substrate and assume an influence of the outcome despite limitations.

Over a 24-month period, 26 endocardial and four epicardial maps were obtained of 26 VT patients (18 ischemic cardiomyopathy (ICM, 69.2%) and 8 non-ischemic cardiomyopathy (NICM, 30.8%), age 65 ± 9 years). Catheter ablation (CA) was performed with the aim of transecting the isthmus. The endpoint was non-inducibility of any VT. Manual review of the maps was performed and focused on evaluating scarring, bipolar electrograms, and procedure times.

In 55.6 ± 34.4 min, 1,085.9 ± 726.2 points were created. The mean ablation time was 50.8 ± 30.1 min. The endpoint was achieved in 12 patients (46.2%). The mean dense scar area and the mean patchy scar area were 49.4 ± 51.8 cm² (range 0 - 190 cm²) and 14.7 ± 14.9 cm² (range 0 - 110 cm²), respectively. Analyzing the learning curve, we found a tendency in decreasing procedure times. During the course of follow-up treatment averaging a 14-month period, device interrogation showed that 17 patients (65.4%) had remained free of any arrhythmia recurrence.

The high-density maps with PentaRay^® were safely created in a short period of time. Our manual review of the maps reveals limitations of current annotation criteria; nevertheless, medium-term outcomes were encouraging. Further prospective studies are required to validate our findings in a larger cohort of patients.