Matthew S Sulkin1, Jacob I Laughner2, Sebastian Hilbert2, Suraj Kapa2, Jedrzej Kosiuk2, Paul Younan2, Iñaki Romero2, Allan Shuros2, Jason J Hamann2, Gerhard Hindricks2, Andreas Bollmann2. 1. Electrophysiology, Boston Scientific Corp, St. Paul, MN (M.S.S., J.I.L., P.Y., I.R., A.S., J.J.H.); Department of Electrophysiology, University Leipzig - Heart Center, Germany (S.H., J.K., G.H., A.B.); and Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, MN (S.K.). matthew.sulkin@bsci.com. 2. Electrophysiology, Boston Scientific Corp, St. Paul, MN (M.S.S., J.I.L., P.Y., I.R., A.S., J.J.H.); Department of Electrophysiology, University Leipzig - Heart Center, Germany (S.H., J.K., G.H., A.B.); and Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic, Rochester, MN (S.K.).
Abstract
BACKGROUND: Coupling between the ablation catheter and myocardium is critical to resistively heat tissue with radiofrequency ablation. The objective of this study was to evaluate whether a novel local impedance (LI) measurement on an ablation catheter identifies catheter-tissue coupling and is predictive of lesion formation. METHODS AND RESULTS: LI was studied in explanted hearts (n=10 swine) and in vivo (n=10; 50-70 kg swine) using an investigational electroanatomic mapping system that measures impedance from an ablation catheter with mini-electrodes incorporated in the distal electrode (Rhythmia and IntellaNav MiFi OI, Boston Scientific). Explanted tissue was placed in a warmed (37 °C) saline bath mounted on a scale, and LI was measured 15 mm away from tissue to 5 mm of catheter-tissue compression at multiple catheter angles. Lesions were created with 31 and 50 W for 5 to 45 seconds (n=90). During in vivo evaluation of LI, measurements of myocardium (n=90) and blood pool (n=30) were guided by intracardiac ultrasound while operators were blinded to LI data. Lesions were created with 31 and 50 W for 45 seconds in the ventricles (n=72). LI of myocardium (119.7 Ω) was significantly greater than that of blood pool (67.6 Ω; P<0.01). Models that incorporate LI drop (ΔLI) to predict lesion size had better performance than models that incorporate force-time integral (R2=0.75 versus R2=0.54) and generator impedance drop (R2=0.82 versus R2=0.58). Steam pops displayed a significantly higher starting LI and larger ΔLI compared with successful radiofrequency applications (P<0.01). CONCLUSIONS: LI recorded from miniature electrodes provides a valuable measure of catheter-tissue coupling, and ΔLI is predictive of lesion formation during radiofrequency ablation.
BACKGROUND: Coupling between the ablation catheter and myocardium is critical to resistively heat tissue with radiofrequency ablation. The objective of this study was to evaluate whether a novel local impedance (LI) measurement on an ablation catheter identifies catheter-tissue coupling and is predictive of lesion formation. METHODS AND RESULTS: LI was studied in explanted hearts (n=10 swine) and in vivo (n=10; 50-70 kg swine) using an investigational electroanatomic mapping system that measures impedance from an ablation catheter with mini-electrodes incorporated in the distal electrode (Rhythmia and IntellaNav MiFi OI, Boston Scientific). Explanted tissue was placed in a warmed (37 °C) saline bath mounted on a scale, and LI was measured 15 mm away from tissue to 5 mm of catheter-tissue compression at multiple catheter angles. Lesions were created with 31 and 50 W for 5 to 45 seconds (n=90). During in vivo evaluation of LI, measurements of myocardium (n=90) and blood pool (n=30) were guided by intracardiac ultrasound while operators were blinded to LI data. Lesions were created with 31 and 50 W for 45 seconds in the ventricles (n=72). LI of myocardium (119.7 Ω) was significantly greater than that of blood pool (67.6 Ω; P<0.01). Models that incorporate LI drop (ΔLI) to predict lesion size had better performance than models that incorporate force-time integral (R2=0.75 versus R2=0.54) and generator impedance drop (R2=0.82 versus R2=0.58). Steam pops displayed a significantly higher starting LI and larger ΔLI compared with successful radiofrequency applications (P<0.01). CONCLUSIONS: LI recorded from miniature electrodes provides a valuable measure of catheter-tissue coupling, and ΔLI is predictive of lesion formation during radiofrequency ablation.
Authors: Sarah R Gutbrod; Allan Shuros; Vijay Koya; Michelle Alexander-Curtis; Lauren Lehn; Kimberly Miklos; John Paul Mounsey; Jason D Meyers Journal: Front Physiol Date: 2022-01-10 Impact factor: 4.566
Authors: Xiaowei Zhao; Ohad Ziv; Reza Mohammadpour; Benjamin Crosby; Walter J Hoyt; Michael W Jenkins; Christopher Snyder; Christine Hendon; Kenneth R Laurita; Andrew M Rollins Journal: Sci Rep Date: 2021-12-21 Impact factor: 4.379