Abstract
We aimed to describe VT isthmii characteristics mapped with a high density mapping catheter and an original algorithm to reconstruct activation (Orion catheter, Rythmia, Boston Scientific).
Methods: All cases of patients with VT ablation performed with Rythmia (Boston Scientific) in 3 tertiary centers were reviewed. In this population all patients with at least one VT mapped during the procedure were included. Isthmii were identified at the area of shortest path width. Measures are depicted in the figure. Mean conduction velocity was measured between the entrance within the isthmus and the exit. Slowest conduction velocity was measured throughout the isthmus.
Results: Fifty-seven patients had VT ablation performed with the Rythmia system. Of those, 16 ( 15 M; 60 ±19 yo) had a VT mapped. Ischemic CMP was the main substrate (75%) and mean LVEF was 45 ±15%. Mean VTCL was 462 ±110ms. A total of 16 VT have been mapped, one was septal without isthmus identified. On the remaining 15, mean isthmus length, width and conduction velocity were 24.8 ±16.3 mm, 6.9 ±1.6 mm and 0.18± 0.13 m/s. The slowest conduction velocity throughout the circuit was 0.03 ±0.02 m/s. Of note the slowest conduction velocity was at one of the extremity of the isthmus (entrance or exit) in 14 VT.
Conflict of interest: Boston Scientific
