Letter by Bartoletti et al Regarding Article, “Ablation of Persistent Atrial Fibrillation Targeting Low-Voltage Areas With Selective Activation Characteristics”

HomeCirculation: Arrhythmia and ElectrophysiologyVol. 9, No. 7Letter by Bartoletti et al Regarding Article, "Ablation of Persistent Atrial Fibrillation Targeting Low-Voltage Areas With Selective Activation Characteristics" Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyRedditDiggEmail Jump toFree AccessLetterPDF/EPUBLetter by Bartoletti et al Regarding Article, "Ablation of Persistent Atrial Fibrillation Targeting Low-Voltage Areas With Selective Activation Characteristics" Stefano Bartoletti, MD Shefali Parikh, and MBBS Dhiraj GuptaMD Stefano BartolettiStefano Bartoletti Institute of Cardiovascular Medicine and Science Liverpool Heart and Chest Hospital Liverpool, United Kingdom , Shefali ParikhShefali Parikh Institute of Cardiovascular Medicine and Science Liverpool Heart and Chest Hospital Liverpool, United Kingdom , and Dhiraj GuptaDhiraj Gupta Institute of Cardiovascular Medicine and Science Liverpool Heart and Chest Hospital Liverpool, United Kingdom Originally published7 Jul 2016https://doi.org/10.1161/CIRCEP.116.004302Circulation: Arrhythmia and Electrophysiology. 2016;9:e004302To the Editor:We congratulate Jadidi et al1 on their interesting article, "Ablation of Persistent Atrial Fibrillation Targeting Low-Voltage Areas With Selective Activation Characteristics." They prospectively enrolled 85 patients with persistent atrial fibrillation undergoing ablation with a stepwise approach. No further lesions beyond pulmonary vein isolation (PVI) were delivered in 23 (27%), who were in sinus rhythm at the start or reverted to sinus rhythm during PVI. In the remaining 62 patients, further lesions were delivered within low-voltage areas (LVA) in the left atrium or in their borders. They found that these 62 cases had higher success rates compared with PVI-only controls chosen from a historical population.A couple of observations are in order:It is widely agreed that bipolar voltages are best measured in a stable sinus or paced rhythm because chaotic activation in atrial fibrillation attenuates local potentials, often variably and unpredictably.2 Yet Jadidi et al1 chose to use bipolar voltages in atrial fibrillation to identify LVAs in the vast majority of their patients. Furthermore, when measured in a stable rhythm, previous studies have been consistent in proposing threshold values of <0.50 mV for LVAs and <0.05 to 0.10 mV for dense scar.3–5 Jadidi et al2 used a much more liberal threshold of <1.0 mV in sinus rhythm to tag LVAs. This may have had the impact of overestimating LVA prevalence, in that >25% of the left atrium area in their population was LVA, which is a much higher proportion than reported previously.2–4Using a historical control group inevitably introduces bias, particularly related to the use of different ablation technologies. For instance, the authors used both contact force–sensing and non–contact force-sensing ablation catheters in their prospective 85 cases. Although they do not mention the ablation technology used in their retrospective controls, given that these cases were performed between 2010 and 2012, it is highly likely that contact force–sensing catheters were not used. It is probable that this difference in ablation technology contributed to the difference in outcomes observed. It is also notable that in the 2 prospective groups where identical technology was used, the 23 PVI-only cases had equally good clinical outcomes as the 62 cases, who underwent additional LVA-targeted ablation. One can easily argue that this suggests that LVAs (especially when liberally defined as <1.0 mV) are mere bystander phenomena with no adverse impact on clinical outcomes once PVI is achieved.The authors conclude, "ablation of sites with distinct activation characteristics within/at borderzones of LVA in addition to PVI is more effective than conventional PVI-only strategy for persistent AF." Lest we forget, countless numbers of patients over many years were subjected to unnecessarily additional ablation in the form of linear lesions and complex fractionated electrogram ablation before the futility of this approach was shown in randomized controlled trials. Given the limitations of this study of being a small observational one using historical controls, we feel that LVA-targeted ablation strategy needs to be tested in prospective randomized studies before it gets incorporated into routine clinical practice.Stefano Bartoletti, MDShefali Parikh, MBBSDhiraj Gupta, MDInstitute of Cardiovascular Medicine and ScienceLiverpool Heart and Chest HospitalLiverpool, United KingdomDisclosuresDr Gupta has received speaker fees, research grants, and fellowship support from Biosense Webster Inc. The other authors report no conflicts.References1. Jadidi AS, Lehrmann H, Keyl C, Sorrel J, Markstein V, Minners J, Park CI, Denis A, Jaïs P, Hocini M, Potocnik C, Allgeier J, Hochholzer W, Herrera-Siklody C, Kim S, Omri YE, Neumann FJ, Weber R, Haïssaguerre M, Arentz T. Ablation of persistent atrial fibrillation targeting low-voltage areas with selective activation characteristics.Circ Arrhythm Electrophysiol. 2016; 9:e002962. doi: 10.1161/CIRCEP.115.002962.LinkGoogle Scholar2. Teh AW, Kistler PM, Lee G, Medi C, Heck PM, Spence SJ, Sparks PB, Morton JB, Sanders P, Kalman JM. The relationship between complex fractionated electrograms and atrial low-voltage zones during atrial fibrillation and paced rhythm.Europace. 2011; 13:1709–1716. doi: 10.1093/europace/eur197.CrossrefMedlineGoogle Scholar3. Lin Y, Yang B, Garcia FC, Ju W, Zhang F, Chen H, Yu J, Li M, Gu K, Cao K, Callans DJ, Marchlinski FE, Chen M. Comparison of left atrial electrophysiologic abnormalities during sinus rhythm in patients with different type of atrial fibrillation.J Interv Card Electrophysiol. 2014; 39:57–67. doi: 10.1007/s10840-013-9838-y.CrossrefMedlineGoogle Scholar4. Squara F, Frankel DS, Schaller R, Kapa S, Chik WW, Callans DJ, Marchlinski FE, Dixit S. Voltage mapping for delineating inexcitable dense scar in patients undergoing atrial fibrillation ablation: a new end point for enhancing pulmonary vein isolation.Heart Rhythm. 2014; 11:1904–1911. doi: 10.1016/j.hrthm.2014.07.027.CrossrefMedlineGoogle Scholar5. Rolf S, Kircher S, Arya A, Eitel C, Sommer P, Richter S, Gaspar T, Bollmann A, Altmann D, Piedra C, Hindricks G, Piorkowski C. Tailored atrial substrate modification based on low-voltage areas in catheter ablation of atrial fibrillation.Circ Arrhythm Electrophysiol. 2014; 7:825–833. doi: 10.1161/CIRCEP.113.001251.LinkGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetails July 2016Vol 9, Issue 7Article InformationMetrics Download: 60 © 2016 American Heart Association, Inc.https://doi.org/10.1161/CIRCEP.116.004302PMID: 27390212 Originally publishedJuly 7, 2016 PDF download SubjectsCatheter Ablation and Implantable Cardioverter-DefibrillatorAtrial Fibrillation