ABC | Volume 114, Nº6, June 2020

Original Article Saad et al. Zero Fluoroscopy Catheter Ablation for Atrial Fibrillation and Supraventricular Arrhythmias Arq Bras Cardiol. 2020; 114(6):1015-1026 ICE and the CARTO 3 system with contact force ablation catheters. No difference in arrhythmia-free 12-month survival was found. No severe complications were recorded in either group. In this series, the fluoroscopy group had an average exposure of 3 min for AF ablations, showing that the operators were already experts in the use of non-fluoroscopic imaging. Taken together, these data suggest that the adoption of radiation reduction measures can dramatically affect x-ray exposure even in fluoroscopically-guided procedures, with no safety concerns. EA mapping is a fundamental part of the procedure since it provides a reliable geometry to guide the roving catheter and RF applications but could potentially provide misleading information if not stringently used. The initial description by Reddy et al. 12 reported a series of 20 consecutive AF ablation procedures without the use of fluoroscopy, relying only on ICE images and the NavX EA system to create geometry. In this series, EA image integration with a previously acquired left atrium CT scan was used in the majority of patients, requiring femoral artery access and aortic root mapping to create a reliable fusion between aortic anatomy from EA mapping and CT image. New technologies, such as multielectrode mapping catheters and software can provide a less traumatic, fast, and reliable geometry, with a high-density map and better anatomy delineation, comparable to a CT scan reconstruction, without the need to expose the patient to radiation and avoiding arterial access during the procedure. In our series, no patient was submitted to pre-ablation CT scans. Also, the EA systems provide ablation catheter tip color-coding orientation that allows easily reproducible movements and an excellent correlation between torque, deflection, and contact force. In our country, only two companies currently provide EA mapping systems - Carto 3 system (BiosenseWebster, Diamond Bar, CA, USA) and Ensite-NavX system (St. Jude Medical, St. Paul, MN, USA). When these two systems were compared for mapping and CTI catheter ablation, Macias et al. showed 4 that the results (acute success, complications, and recurrence rates) from both EA mapping systems were similar. In our study, Carto 3 was used in 67.8% of patients, and the NavX system in 32.2% of all procedures (Table 1), with similar results. ICE visualization is critical in every step of a non- fluoroscopic complex ablation. With thorough ICE scanning, all the steps can be adequately monitored, even when catheters come out of the sheath tip (making sure it does not force the atrial wall). There is no blind step using this approach, even when advancing catheters or wires in the venous system to the heart. CS visualization and cannulation are better than with fluoroscopy, not to mention the transseptal punctures, which are undoubtedly best visualized on ICE. Baykaner et al. 23 recently reported on 747 zero-fluoroscopy transeptal punctures, performed in 646 patients in 5 different centers across the US, using different approaches to reach the fossa ovalis. The transseptal access was associated with a low total complication rate (0.7%). In our study, a total of 142 transseptal punctures were performed with no complications. Indeed, a somewhat short learning curve is needed to become comfortable with and proficient in ICE manipulation. But it definitively gives better and more detailed information than fluoroscopy. Razminia et al. 15 reported a 5-year follow-up of fluoroless ablations in a series of 500 patients. These procedures were safely and effectively performed, with similar rates of recurrence and complications when compared with the standard technique. In our series, we also did not observe any significant complications. As this technique becomes the standard practice for even more complex procedures, such as ventricular tachycardias, a rise in complications rate could be expected. As such, reports on the safety and effectiveness for the patient are extremely important and will, together with more widespread training in ICE and EA mapping, be vital to large-scale adoption of these procedures in clinical practice. All the tools needed for a successful radiation-free ablation are already available in most EP labs and familiar to most EP physicians. 24 Engagement in this field only needs a motivated team with a change in mindset. Once one does it, there is no way back. It is highly beneficial to patients – who can frequently undergo more than one ablation, usually have other diagnostic or therapeutic modalities that use radiation (e.g., CT scans, coronary interventions) over their lifespan, which are usually unaccounted for or neglected. The risk is cumulative over time. We have to keep that in mind, especially when cancer statistics show a worrying steep rise and when the impact can occur years after exposure. Radiation-free interventions also allow safe ablation treatment of pregnant patients. Themost recently published ESC Guidelines for the treatment of supraventricular arrhythmias 25 gives an IIa indication in experienced centers. Even for standard SVT cases, where simple procedures under conscious sedation and using two catheters are frequently performed, it is worthwhile using ICE and general anesthesia. They allow for safe and comfortable procedures for both pts and physicians and add the possibility of using transient apnea to enhance catheter stability when dealing with arrhythmias near the AV node / His bundle. Zero fluoroscopy is also highly beneficial to the health care team. First, reducing the radiation exposure is obviously desired for people who have been exposed daily for years. It is a matter of concern to read reports of an increase of up to 1% in one’s lifetime risk of cancer; 3,7 it is uncomfortable to read reports that 85% of brain cancers in interventional physicians occur on the left hemisphere, 26-28 suggesting a causal relation to occupational exposure to radiation effects (since the left side is known to be more exposed than the right). Not to mention the considerable benefit of avoiding using heavy lead aprons, which, over time, makes orthopedic issues an almost unanimous occurrence. 29-31 The authors cannot stress enough themassive relief that standing hours without having to wear heavy lead aprons represents. It is also highly beneficial to patients and all the healthcare team. Multiple exposures to radiation are common in the modern era, with the readily available imaging modalities. We usually do not realize the cumulative nature of multiple exposures and their potential detrimental effects over the long term. Patients undergoing ablation not uncommonly have had or will have repeated exposure to CT, fluoroscopy, coronary and peripheral angiography, as well as nuclear scans. A radiation-free procedure with at least similar costs, safety, and effectiveness as the standard fluoro-based alternative, even when additional hardware is implanted in the heart, is thus highly valuable. A 1023