Abstract 15634: Contact Force Mapping of Human Cardiac Ganglionnated Plexuses
Background: The intrinsic cardiac nervous system consists of ganglionnated plexuses (GP) localized to specific regions of the LA. The relation between endocardial contact force during catheter mapping and autonomic effects associated with stimulation of GP’s has not previously been evaluated.
Objective: To determine the thresholds associated with GP stimulation in relation to endocardial catheter pressure, using a new catheter that provides measurement of contact force (SmartTouch, Biosense-Webster, CA)
Methods: Thirteen patients with symptomatic atrial fibrillation (AF) underwent catheter ablation of AF. Pre-acquired CT imaging provided delineation of the LA and pulmonary veins (PV). Following transseptal access, 3D non-fluoroscopic mapping was obtained to recreate the LA and PV’s, while merging techniques were performed to integrate CT imaging with 3D maps. Using High Frequency Stimulation (HFS), patient specific mapping of GP’s was obtained, consisting of left upper and inferior PV’s (LUPV, LIPV), right upper and inferior PV’s (RUPV, RIPV), as well as the region of the Crux. At each location, the contact force measurement from the catheter was correlated with the voltage applied during HFS at 5V, 10V or 15V to obtain an autonomic effect, defined as a decrease of the mean heart rate or blood pressure by 50%, but typically showing for each site no blood pressure during HFS.
Results: There were 147 applications of HFS, resulting in GP identification in all patients (mean 3.5 per patient, range 1-5). The highest regions of contact force required to obtain a positive GP were in the RUPV and LIPV, requiring a mean contact force of 25.5 gm at 10V (range 14-50). The lowest regions of contact force associated with positive GP were in the Crux and LUPV, requiring a mean contact force of 8.6 gm at 5V-10V (range 2-21). During HFS at 15V, a sudden overshoot with maximal values of contact force was also observed.
Conclusions: We provide the first report evaluating the relation between contact force during catheter mapping and precise determination of GP localization during HFS. The GP’s are epicardial structures that require site specific voltage delivery during HFS; significant contact force may be required to result in an autonomic response.
- © 2013 by American Heart Association, Inc.