Author + information
- Matthew Wright, MB, BS, PhDa,
- Erik Harks, PhDb,
- Szabolcs Deladi, PhDb,
- Steven Fokkenrood, MScb,
- Rob Brink, BScb,
- Harm Belt, PhDc,
- Alexander F. Kolen, PhDc,
- Darrell Rankin, MEngd,
- William Stoffregen, DVMd,
- Debra A. Cockayne, PhDd,
- Joseph Cefalu, BScd and
- David E. Haines, MDe,∗ ()
- aDivision of Imaging Sciences and Biomedical Engineering, King’s College London, United Kingdom and Department of Cardiology, St. Thomas’ Hospital, London, United Kingdom
- bPhilips Healthcare, Best, the Netherlands
- cPhilips Research, Eindhoven, the Netherlands
- dBoston Scientific Corporation, San Jose, California
- eDepartment of Cardiovascular Medicine, Beaumont Health System and Oakland University William Beaumont School of Medicine, Royal Oak, Michigan
- ↵∗Address for correspondence:
Dr. David E. Haines, Oakland University William Beaumont School of Medicine, Heart Rhythm Center, Beaumont Health System, 3601 West 13 Mile Road, Royal Oak, Michigan 48073.
Objectives Visualizing myocardium with near field ultrasound (NFUS) transducers in the tip of the catheter might provide an image of the evolving pathological lesion during energy delivery.
Background Radiofrequency (RF) catheter ablation has been effective in arrhythmia treatment, but no technology has allowed lesion formation to be visualized in real time in vivo.
Methods RF catheter ablations were performed in vivo with the goal to create transmural atrial lesions and large ventricular lesions. RF lesion formation was imaged in real time using M-mode, tissue Doppler, and strain rate information from the NFUS open irrigated RF ablation catheter incorporating 4 ultrasound transducers (1 axial and 3 radial), and growth kinetics were analyzed. Nineteen dogs underwent ablation in the right and left atria (n = 185), right ventricle (n = 67), and left ventricle (n = 66). Lesions were echolucent with tissue strain rate by NFUS.
Results Lesion growth frequently progressed from epicardium to endocardium in thin-walled tissue. The half time of lesion growth was 5.5 ± 2.8 s in thin-walled and 9.7 ± 4.3 s in thick-walled tissue. Latency of lesion onset was seen in 57% of lesions ranging from 1 to 63.8 s. Tissue edema (median 25% increased wall thickness) formed immediately upon lesion formation in 83%, and intramyocardial steam was seen in 71% of cases.
Conclusions NFUS was effective in imaging RF catheter ablation lesion formation in real time. It was useful in assessing the dynamics of lesion growth and could visualize impending steam pops. It may be a useful technology to improve both safety and efficacy of RF catheter ablation.
Research funding was provided by Philips Healthcare, Best, the Netherlands and Boston Scientific Corporation, Inc., San Jose, California. Dr. Wright and Dr. Haines have received research support from Philips Healthcare and Boston Scientific Corporation. Drs. Harks, Deladi, Betl, and Kolen, Mr. Fokkenrood, and Mr. Brink have been employed by Philips Healthcare. Mr. Rankin, Drs. Stoffregen and Cockayne, and Mr. Cefalu have been employed by Boston Scientific Corporation.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received January 22, 2018.
- Revision received March 22, 2018.
- Accepted April 12, 2018.
- 2018 The Authors
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