Maximum voltage gradient technique for optimization of ablation for typical atrial flutter with zero-fluoroscopy approach

Abstract

Radiofrequency catheter ablation (RFCA) is an established effective method for the treatment of typical cavo-tricuspid isthmus (CTI)-dependent atrial flutter (AFL). The introduction of 3-dimensional electro-anatomic systems enables RFCA without fluoroscopy (No-X-Ray [NXR]). The aim of this study was to evaluate the feasibility and effectiveness of CTI RFCA during implementation of the NXR approach and the maximum voltage-guided (MVG) technique for ablation of AFL.Data were obtained from prospective standardized multicenter ablation registry. Consecutive patients with the first RFCA for CTI-dependent AFL were recruited. Two navigation approaches (NXR and fluoroscopy based as low as reasonable achievable [ALARA]) and 2 mapping and ablation techniques (MVG and pull-back technique [PBT]) were assessed. NXR + MVG (n = 164; age: 63.7 ± 9.5; 30% women), NXR + PBT (n = 55; age: 63.9 ± 10.7; 39% women); ALARA + MVG (n = 36; age: 64.2 ± 9.6; 39% women); and ALARA + PBT (n = 205; age: 64.7 ± 9.1; 30% women) were compared, respectively. All groups were simplified with a 2-catheter femoral approach using 8-mm gold tip catheters (Osypka AG, Germany or Biotronik, Germany) with 15 min of observation. The MVG technique was performed using step-by-step application by mapping the largest atrial signals within the CTI.Bidirectional block in CTI was achieved in 99% of all patients (P = NS, between groups). In NXR + MVG and NXR + PBT groups, the procedure time decreased (45.4 ± 17.6 and 47.2 ± 15.7 min vs. 52.6 ± 23.7 and 59.8 ± 24.0 min, P < .01) as compared to ALARA + MVG and ALARA + PBT subgroups. In NXR + MVG and NXR + PBT groups, 91% and 98% of the procedures were performed with complete elimination of fluoroscopy. The NXR approach was associated with a significant reduction in fluoroscopy exposure (from 0.2 ± 1.1 [NXR + PBT] and 0.3 ± 1.6 [NXR + MVG] to 7.7 ± 6.0 min [ALARA + MVG] and 9.1 ± 7.2 min [ALARA + PBT], P < .001). The total application time significantly decreased in the MVG technique subgroup both in NXR and ALARA (P < .01). No major complications were observed in either groups.Complete elimination of fluoroscopy is feasible, safe, and effective during RFCA of CTI in almost all AFL patients without cardiac implanted electronic devices. The most optimal method for RFCA of CTI-dependent AFL seems to be MVG; however, it required validation of optimal RFCA's parameters with clinical follow-up.

The use of minimal fluoroscopy for cardiac electrophysiology procedures: A meta‐analysis and review of the literature

“…7 This study provides an update to a previously published meta-analysis by including five additional studies (one randomized and four nonrandomized studies). [10][11][12][13][14] In total, we included 15 clinical studies involving 3795 patients who underwent catheter ablation with MF or conventional fluoroscopy for cardiac arrhythmias. Our results demonstrate a significant reduction in fluoroscopic time, radiation dose and…”

“…There has been an increased interest in performing MF techniques particularly since the last meta‐analysis was published on this topic 7 . This study provides an update to a previously published meta‐analysis by including five additional studies (one randomized and four non‐randomized studies) 10‐14 . In total, we included 15 clinical studies involving 3795 patients who underwent catheter ablation with MF or conventional fluoroscopy for cardiac arrhythmias.…”

Minielectrode catheter technology for near zero-fluoroscopy substrate-guided ablation of typical atrial flutter

“…18 The MVG approach directly targets muscle bundles identified by local high-voltage electrograms. Reproduced by many other working groups, 9,13,19 the concept was proven by Gula and colleagues 11,20 in 2006 and 2009, showing a significant reduction of ablation requirements for the MVG approach compared with linear ablation. However, no correlation was found between the initial CTI voltage and ablation requirements that could be explained by less effective lesions applied at previously ablated sites.…”

“…Therefore, accurate identification of MV areas and precisely targeted radiofrequency energy (RFE) application are decisive factors. Although a reduction of ablation requirements has been shown, [9][10][11][12][13] the current evidence is still considered to not be robust enough to suggest a general change in the ablation strategy. 14 In addition, there are conflicting data regarding fluoroscopy time (FT).…”

“…14 In addition, there are conflicting data regarding fluoroscopy time (FT). 9,11 MicroFidelity sensor technology (Boston Scientific, North Quincy, MA) was developed to enhance spatial resolution of large-tip catheters using 3 minielectrodes (ME) with a diameter of 1.2 mm radially integrated into the distal tip. By reducing the gap between the origin of high-resolution (HR) signals and the center of RFE application, this technology may facilitate MVG ablation.…”