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 Figure 2 – ICE imaging sequence examples of LAmapping and ablation. These were recorded after the ICE catheter was placed in the LAcavity across the septum. A) Amultipolar high-density mapping catheter (Pentarray – Biosense Webster, marked by arrow) is collecting anatomic and electric data around the left atrial appendage (LAA). MV – mitral valve. B) The tip of the contact force-sensor ablation catheter is floating in the LA cavity. As it is not touching any structure, this is a good spot to calibrate the sensor as zero force. This step is needed before initiating RF delivery. C) The ablation catheter is highlighted at the roof of the LA around the LSPV. The mapping catheter (arrow) is inside the LSPV monitoring its electrical connection to the LA. It is clear that the ablation catheter is in the PV antrum and not delivering energy inside the vein. D) Ablation in the ridge (*) between the LSPV and the LAA. The mapping catheter is inside the LSPV (arrow). to check for pericardial effusion, at the following times: (1) at baseline, (2) after transeptal punctures, (3) after left PV isolation, (4) after right PV isolation, (5) and at the end of procedure. ICE also allows for immediate detection of clot formation, which cannot be seen with other non-ultrasound imaging modalities. In pacemaker patients, device interrogation was performed before and after the procedure to guarantee lead integrity. Femoral vein access care was performed with figure-of-eight sutures with Prolene “0” to achieve full hemostasis. Protamine at a maximal dose of 50 mg IV was given to allow for partial reversal of anticoagulation. Deambulation was allowed after 6h, and oral anticoagulation was resumed on the same day. SVT Cases For SVT cases, a routine somewhat similar to AF cases was used. To facilitate multipolar catheter advancement in the absence of transseptal sheaths, long sheaths that deliver the catheters in the inferior vena cava (IVC) were preferred, thus avoiding the anatomical tortuosity of the femoral and iliac vessels. Starting from that site, progression to the RA was marked by the appearance of atrial electrograms and ICE visualization, as described. Anatomical landmarks such as His bundle and CS, SVC, IVC, and right atrial appendage ostia were tagged in the EA maps under ICE guidance (figure 4). Population studied We report a series of consecutive, unselected cases of catheter ablation procedures for the treatment of atrial tachyarrhythmias (AF, atrial flutter, and SVTs) performed without fluoroscopy, exclusively guided by ICE and EA mapping. Excel software (2019 version) was used for data tabulation. The main goals are to describe the feasibility of this innovative approach and to show the safety profile of this technique. From May/2019 to December/2019, 95 consecutive patients (mean age 60 ± 18 years, 61% males) referred for ablation underwent the zero fluoro approach, with the following procedure distribution: AF Ablation (69 pts [73%], 45 paroxysmal AF [47%] and 24 persistent AF [25%]) or non- AF SVT (26 pts [27%] – 14 AV node reentry [15%], 6 WPW syndrome [6% - 4 in the mitral and 2 in the tricuspid annulus], 5 right atrial (RA) typical flutters [5%], 1 atrial tachycardia [1%]). In AF pts, the mean LA volume was 36 ± 4 ml/m 2 and 36% (25 pts) had structural heart disease, including rheumatic (3 pts - 3%) and other types of valvular disease (8 pts - 8%), coronary artery disease (17 pts - 17%), post-open heart surgery pts (12 pts - 12%, which usually have LA, RA and septal scars and sutures). Patients and procedural characteristics are summarized in table 1 and figure 5. The protocol included an overnight hospital stay in a telemetry bed. No routine imaging was required before 1019