title: The Incidence of Audible Steam Pops Is Increased and Unpredictable With the ThermoCool® Surround Flow Catheter During Left Atrial Catheter Ablation: A Prospective Observational Study.
abstract: BACKGROUND
  Open irrigated radiofrequency (RF) ablation catheters with a porous tip (56 holes, TC-SF) permit delivering RF energy in a temperature-controlled mode without temperature rise. This prospective observational study investigated the association of different catheter parameters on the occurrence of audible steam pops during left atrial (LA) ablation.
  
  
  RESULTS
  A total of 226 patients underwent TC-SF catheter ablation for atrial fibrillation. RF power delivery, impedance and catheter tip temperature were continually recorded throughout the ablation. Pulmonary vein isolation was performed with a maximum of 27 W and LA electrogram-guided or linear ablation with a maximum of 30 W. A total of 59 audible steam pops occurred, 2 of them resulting in pericardial tamponade. In the initial 89 patients, with an irrigation flow rate of 10 mL/min, 18 steam pops with one tamponade occurred in 12 (14%) patients. Subsequently, the irrigation flow rate was increased to 20 mL/min in the following 137 patients, resulting in the occurrence of 41 steam pops including one case of tamponade in a total of 30 (22%) patients. The maximal power was significantly higher in RF applications associated with a pop than those that did not. In only 12 (20%) steam pops, a significant impedance change occurred immediately before pop occurrence (4 [7%] impedance rise >10 ohm, 8 [13%] impedance drop >15 ohm).
  
  
  CONCLUSIONS
  The TC-SF catheter does not provide sufficient feedback from the ablated tissue to prevent steam popping.
authors.affiliation: II. Medical Clinic, Department of Electrophysiology, Johannes Gutenberg-University Mainz, Germany.
authors.forename: Cathrin
authors.initials: C
authors.lastname: Theis
authors.affiliation: II. Medical Clinic, Department of Electrophysiology, Johannes Gutenberg-University Mainz, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rostock
authors.affiliation: II. Medical Clinic, Department of Electrophysiology, Johannes Gutenberg-University Mainz, Germany.
authors.forename: Hanke
authors.initials: H
authors.lastname: Mollnau
authors.affiliation: II. Medical Clinic, Department of Electrophysiology, Johannes Gutenberg-University Mainz, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Sonnenschein
authors.affiliation: II. Medical Clinic, Department of Electrophysiology, Johannes Gutenberg-University Mainz, Germany.
authors.forename: Ewald
authors.initials: E
authors.lastname: Himmrich
authors.affiliation: II. Medical Clinic, Department of Electrophysiology, Johannes Gutenberg-University Mainz, Germany.
authors.forename: Denise
authors.initials: D
authors.lastname: Kämpfner
authors.affiliation: II. Medical Clinic, Department of Electrophysiology, Johannes Gutenberg-University Mainz, Germany.
authors.forename: Blanca Quesada
authors.initials: BQ
authors.lastname: Ocete
authors.affiliation: II. Medical Clinic, Department of Electrophysiology, Johannes Gutenberg-University Mainz, Germany.
authors.forename: Karsten
authors.initials: K
authors.lastname: Bock
authors.affiliation: II. Medical Clinic, Department of Electrophysiology, Johannes Gutenberg-University Mainz, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Münzel
authors.affiliation: II. Medical Clinic, Department of Electrophysiology, Johannes Gutenberg-University Mainz, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Konrad
keywords: ThermoCool®-Surround Flow catheter; atrial fibrillation; cardiac tamponade; catheter ablation; irrigated-tip ablation; steam pop