title: Electrogram-gated radiofrequency ablations with duty cycle power delivery negate effects of ablation catheter motion.
abstract: BACKGROUND
  Cardiac and respiratory movements cause catheter instability. Lateral catheter sliding over target endocardial surface can lead to poor tissue contact and unpredictable lesion formation. We describe a novel method of overcoming the effects of lateral catheter sliding movements using an electrogram-gated pulsed power ablation.
  
  
  RESULTS
  All ablations were performed on a thermochromic gel myocardial phantom. Ablation settings were randomized to conventional (nongated) 30 W versus electrogram-gated at 20% duty cycle (30 W average power) at 0-, 3-, 6-, and 9-mm lateral sliding distances. Forty-eight radiofrequency ablations were performed. Deeper lesions were created in electrogram-gated versus conventional ablations at 3 mm (4.36±0.08 versus 4.05±0.17 mm; P=0.009), 6 mm (4.39±0.10 versus 3.44±0.15 mm; P<0.001), and 9 mm (4.41±0.06 versus 2.94±0.16 mm; P<<0.001) sliding distances. Electrogram-gated ablations created consistent lesions at a quicker rate of growth in depth when compared with conventional ablations (P<0.001).
  
  
  CONCLUSIONS
  (1) Lesion depth decreases and length increases in conventional ablations with greater degrees of lateral catheter movements; (2) electrogram-gated pulsed radiofrequency delivery negated the effects from lateral catheter movement by creating consistently deeper lesions irrespective of the degree of catheter movement; and (3) target lesion depths were reached significantly faster in electrogram-gated than in conventional ablations.
authors.affiliation: From the Cardiology Department, Westmead Hospital (W.W.B.C., M.A.B., J.P., K.B., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), Sydney Medical School (W.W.B.C., M.A.B., J.P., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), and School of Electrical and Information Engineering (M.A.B., A.M.), University of Sydney, Sydney, New South Wales, Australia.
authors.forename: William W B
authors.initials: WW
authors.lastname: Chik
authors.affiliation: From the Cardiology Department, Westmead Hospital (W.W.B.C., M.A.B., J.P., K.B., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), Sydney Medical School (W.W.B.C., M.A.B., J.P., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), and School of Electrical and Information Engineering (M.A.B., A.M.), University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Michael Anthony
authors.initials: MA
authors.lastname: Barry
authors.affiliation: From the Cardiology Department, Westmead Hospital (W.W.B.C., M.A.B., J.P., K.B., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), Sydney Medical School (W.W.B.C., M.A.B., J.P., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), and School of Electrical and Information Engineering (M.A.B., A.M.), University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Jim
authors.initials: J
authors.lastname: Pouliopoulos
authors.affiliation: From the Cardiology Department, Westmead Hospital (W.W.B.C., M.A.B., J.P., K.B., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), Sydney Medical School (W.W.B.C., M.A.B., J.P., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), and School of Electrical and Information Engineering (M.A.B., A.M.), University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Karen
authors.initials: K
authors.lastname: Byth
authors.affiliation: From the Cardiology Department, Westmead Hospital (W.W.B.C., M.A.B., J.P., K.B., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), Sydney Medical School (W.W.B.C., M.A.B., J.P., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), and School of Electrical and Information Engineering (M.A.B., A.M.), University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Christine
authors.initials: C
authors.lastname: Midekin
authors.affiliation: From the Cardiology Department, Westmead Hospital (W.W.B.C., M.A.B., J.P., K.B., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), Sydney Medical School (W.W.B.C., M.A.B., J.P., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), and School of Electrical and Information Engineering (M.A.B., A.M.), University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Bhaskaran
authors.affiliation: From the Cardiology Department, Westmead Hospital (W.W.B.C., M.A.B., J.P., K.B., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), Sydney Medical School (W.W.B.C., M.A.B., J.P., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), and School of Electrical and Information Engineering (M.A.B., A.M.), University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Gopal
authors.initials: G
authors.lastname: Sivagangabalan
authors.affiliation: From the Cardiology Department, Westmead Hospital (W.W.B.C., M.A.B., J.P., K.B., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), Sydney Medical School (W.W.B.C., M.A.B., J.P., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), and School of Electrical and Information Engineering (M.A.B., A.M.), University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Stuart P
authors.initials: SP
authors.lastname: Thomas
authors.affiliation: From the Cardiology Department, Westmead Hospital (W.W.B.C., M.A.B., J.P., K.B., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), Sydney Medical School (W.W.B.C., M.A.B., J.P., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), and School of Electrical and Information Engineering (M.A.B., A.M.), University of Sydney, Sydney, New South Wales, Australia.
authors.forename: David L
authors.initials: DL
authors.lastname: Ross
authors.affiliation: From the Cardiology Department, Westmead Hospital (W.W.B.C., M.A.B., J.P., K.B., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), Sydney Medical School (W.W.B.C., M.A.B., J.P., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), and School of Electrical and Information Engineering (M.A.B., A.M.), University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Alistair
authors.initials: A
authors.lastname: McEwan
authors.affiliation: From the Cardiology Department, Westmead Hospital (W.W.B.C., M.A.B., J.P., K.B., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), Sydney Medical School (W.W.B.C., M.A.B., J.P., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), and School of Electrical and Information Engineering (M.A.B., A.M.), University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Pramesh
authors.initials: P
authors.lastname: Kovoor
authors.affiliation: From the Cardiology Department, Westmead Hospital (W.W.B.C., M.A.B., J.P., K.B., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), Sydney Medical School (W.W.B.C., M.A.B., J.P., C.M., A.B., G.S., S.P.T., D.L.R., P.K., A.T.), and School of Electrical and Information Engineering (M.A.B., A.M.), University of Sydney, Sydney, New South Wales, Australia. a.t@sydney.edu.au.
authors.forename: Aravinda
authors.initials: A
authors.lastname: Thiagalingam
mesh_terms: D062906:Cardiac Catheters; D017115:Catheter Ablation / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D004562:Electrocardiography; D004867:Equipment Design; D008955:Models, Cardiovascular; D009038:Motion; D009206:Myocardium / Q000473:pathology; D013997:Time Factors
keywords: ablation techniques; biophysics; cardiac arrhythmias; cardiac electrophysiology; catheter ablation; radiofrequency ablation