Indication of the radiofrequency induced lesion size by pre-ablation measurements

Abstract

Pre-ablation measurement of DeltaIMP and DeltaT can indicate the lesion size resulting after ablation in temperature-controlled, power-controlled and irrigated ablation in vitro, since DeltaT reflects cavitary cooling and to a smaller extent electrode-tissue contact, and DeltaIMP reflects only electrode-tissue contact.

Visual, tactile, and contact force feedback: Which one is more important for catheter ablation? Results from an in vitro experimental study

“…However, all of them are dependent, to a certain degree, on real contact between catheter and tissue. 16,17,25,26 Two recently published studies, the Toccata 28 and the EFFICAS I 29 trials, confirmed the relevance of applied contact force during AF ablation in terms of recurrences of the arrhythmia 28 or of the incidence of gaps in PV isolation. 29 Our study shows that, during manual and robotic advancement of the catheter, the force applied at ablation level is likely to be 420 g, which identifies a threshold with high likelihood of transmurality 26 and low recurrences at follow-up, 28 but still within a safety limit for the occurrence of pops 16,30 and thrombi.…”

“…[15][16][17] Traditional indirect indicators of efficacious RF ablation are impedance increase pre-RF delivery, 25 drop in impedance 15,17,26 and increase in temperature with tissue heating, 15,16,25 and use of ICE to assess tissue contact. However, all of them are dependent, to a certain degree, on real contact between catheter and tissue.…”

“…Assessment of the real contact force during RF ablation is crucial in order to maximize procedure efficacy 16,17,[25][26][27][28][29] while not impairing its safety. [15][16][17] Traditional indirect indicators of efficacious RF ablation are impedance increase pre-RF delivery, 25 drop in impedance 15,17,26 and increase in temperature with tissue heating, 15,16,25 and use of ICE to assess tissue contact.…”

An in vivo comparison of radiofrequency cardiac lesions formed by standard and magnetically steered 4 mm tip catheters

“…Lesion size depends on tissue temperature which relates to controllable and noncontrollable factors. 1 Controllable factors include catheter tip size (tip surface area), tip orientation, power settings, application time, and temperature cut-off. Non-controllable factors include tip cooling by blood flow and tissue contact.…”

“…These factors have been studied extensively. [1][2][3][4][5][6] A magnetic navigation system (Niobe, Stereotaxis Inc., St. Louis, MO, USA) allows the use of floppy magnetic tip catheters, steered and advanced remotely, using an applied magnetic field and an external advancer system. These catheters may have advantages in positioning in difficult anatomy, and also in maintaining position during ablation.…”