BACKGROUND: Electrode cooling by circulating fluid within the electrode (closed loop) or open irrigation facilitates radiofrequency (RF) ablation. This study compared lesion parameters between closed loop and open irrigation with the use of a canine model. METHODS AND RESULTS: In 8 anesthetized dogs, the skin over the thigh muscle was incised and raised, forming a cradle superfused with heparinized blood (activated clotting time >350 seconds) at 37 degrees C. A 7F 4-mm closed loop electrode (irrigation 36 mL/min) and 7.5F 3.5-mm open irrigation electrode (irrigation 17 mL/min) were positioned perpendicular to the thigh muscle at 10 g contact weight. RF was applied (n=121) at 20 or 30 W for 60 seconds in low (0.1 m/s) or high (0.5 m/s) pulsatile blood flow. Temperatures were measured in the electrode, electrode-tissue interface, and within the tissue at 3- and 7-mm depths. After each RF, the cradle was emptied to examine the electrode and interface for thrombus. There was no difference between closed loop and open irrigation in impedance, lesion depth, or tissue temperature at 20 or 30 W. Interface temperature and electrode temperature were greater in the closed loop application. Thrombus occurred in 32 of 63 closed loop versus 0 of 58 open irrigation RF applications (P<0.05) with interface temperature > or =80 degrees C in all 32 (electrode temperature <40 degrees C in 1, 40 degrees C to 50 degrees C in 26, and >50 degrees C in 5). With closed loop, interface temperature and thrombus incidence were greater at 30 W and low blood flow. With open irrigation, interface temperature remained low (< or =71 degrees C) with no difference between 20 and 30 W or between low and high blood flow. Steam pop occurred at 20 W in 4 of 35 closed loop and 0 of 30 open irrigation and at 30 W in 15 of 28 closed loop and 4 of 28 open irrigation applications (P<0.05). CONCLUSIONS: Lower interface temperature, thrombus, and steam pop, especially in low blood flow, indicate greater interface cooling with open irrigation.
BACKGROUND: Electrode cooling by circulating fluid within the electrode (closed loop) or open irrigation facilitates radiofrequency (RF) ablation. This study compared lesion parameters between closed loop and open irrigation with the use of a canine model. METHODS AND RESULTS: In 8 anesthetized dogs, the skin over the thigh muscle was incised and raised, forming a cradle superfused with heparinized blood (activated clotting time >350 seconds) at 37 degrees C. A 7F 4-mm closed loop electrode (irrigation 36 mL/min) and 7.5F 3.5-mm open irrigation electrode (irrigation 17 mL/min) were positioned perpendicular to the thigh muscle at 10 g contact weight. RF was applied (n=121) at 20 or 30 W for 60 seconds in low (0.1 m/s) or high (0.5 m/s) pulsatile blood flow. Temperatures were measured in the electrode, electrode-tissue interface, and within the tissue at 3- and 7-mm depths. After each RF, the cradle was emptied to examine the electrode and interface for thrombus. There was no difference between closed loop and open irrigation in impedance, lesion depth, or tissue temperature at 20 or 30 W. Interface temperature and electrode temperature were greater in the closed loop application. Thrombus occurred in 32 of 63 closed loop versus 0 of 58 open irrigation RF applications (P<0.05) with interface temperature > or =80 degrees C in all 32 (electrode temperature <40 degrees C in 1, 40 degrees C to 50 degrees C in 26, and >50 degrees C in 5). With closed loop, interface temperature and thrombus incidence were greater at 30 W and low blood flow. With open irrigation, interface temperature remained low (< or =71 degrees C) with no difference between 20 and 30 W or between low and high blood flow. Steam pop occurred at 20 W in 4 of 35 closed loop and 0 of 30 open irrigation and at 30 W in 15 of 28 closed loop and 4 of 28 open irrigation applications (P<0.05). CONCLUSIONS: Lower interface temperature, thrombus, and steam pop, especially in low blood flow, indicate greater interface cooling with open irrigation.
Authors: Edmond M Cronin; Frank M Bogun; Philippe Maury; Petr Peichl; Minglong Chen; Narayanan Namboodiri; Luis Aguinaga; Luiz Roberto Leite; Sana M Al-Khatib; Elad Anter; Antonio Berruezo; David J Callans; Mina K Chung; Phillip Cuculich; Andre d'Avila; Barbara J Deal; Paolo Della Bella; Thomas Deneke; Timm-Michael Dickfeld; Claudio Hadid; Haris M Haqqani; G Neal Kay; Rakesh Latchamsetty; Francis Marchlinski; John M Miller; Akihiko Nogami; Akash R Patel; Rajeev Kumar Pathak; Luis C Saenz Morales; Pasquale Santangeli; John L Sapp; Andrea Sarkozy; Kyoko Soejima; William G Stevenson; Usha B Tedrow; Wendy S Tzou; Niraj Varma; Katja Zeppenfeld Journal: J Interv Card Electrophysiol Date: 2020-10 Impact factor: 1.900
Authors: Hugh Calkins; Karl Heinz Kuck; Riccardo Cappato; Josep Brugada; A John Camm; Shih-Ann Chen; Harry J G Crijns; Ralph J Damiano; D Wyn Davies; John DiMarco; James Edgerton; Kenneth Ellenbogen; Michael D Ezekowitz; David E Haines; Michel Haissaguerre; Gerhard Hindricks; Yoshito Iesaka; Warren Jackman; Jose Jalife; Pierre Jais; Jonathan Kalman; David Keane; Young-Hoon Kim; Paulus Kirchhof; George Klein; Hans Kottkamp; Koichiro Kumagai; Bruce D Lindsay; Moussa Mansour; Francis E Marchlinski; Patrick M McCarthy; J Lluis Mont; Fred Morady; Koonlawee Nademanee; Hiroshi Nakagawa; Andrea Natale; Stanley Nattel; Douglas L Packer; Carlo Pappone; Eric Prystowsky; Antonio Raviele; Vivek Reddy; Jeremy N Ruskin; Richard J Shemin; Hsuan-Ming Tsao; David Wilber Journal: J Interv Card Electrophysiol Date: 2012-03 Impact factor: 1.900
Authors: Prabhat Kumar; J Paul Mounsey; Anil K Gehi; Jennifer D Schwartz; Eugene H Chung Journal: J Interv Card Electrophysiol Date: 2013-04-19 Impact factor: 1.900