Optimal ablation index parameters for radiofrequency ablation therapy of atrial fibrillation

Objective: To explore the optimal ablation index (AI) parameters for radiofrequency catheter ablation (RA) for treating atrial fibrillation (AF). Method: Patients with AF (186) who underwent bilateral PVAI in the Department of Cardiology, Zhuhai People’s Hospital, Guangdong Province, from March 2018 to October 2019 and received catheter ablation as first-round treatment, were grouped according to the received AI. Control group included patients (95) who received the recommended AI ablation (350–400 for posterior wall, 400–450 for non-posterior wall). Patients in optimal AI group were ablated with optimal AI (300–330 for posterior wall, 350–380 for non-posterior wall). Results: Of 186 patients, 66 patients had paroxysmal atrial fibrillation and a mean CHA2DS2-VASc score of 2.83±1.64. Isolation rates of bilateral PVI in both groups were 91.4% and 93.6%, for patients with paroxysmal atrial fibrillation, and 81.7% and 80% for patients with persistent atrial fibrillation (P > 0.05). Left atrial function index (LAFI) decreased under the condition of sinus rhythm at the 3rd and 6th months (P < 0.05). LAFI improvement was significantly better in the optimal AI group than in the control group (P < 0.05). Rates of pain and cough during the ablation, and postoperative gastrointestinal discomfort and use of PPIs were higher in the control group (P < 0.05). Conclusion: Radiofrequency ablation of AF, guided by optimal AI combined with impedance, can minimize atrial injury, prevent atrial failure, promote the recovery of atrial function, reduces intraoperative cough, pain, and postoperative gastrointestinal discomfort and use of PPIs. doi: https://doi.org/10.12669/pjms.38.3.4971 How to cite this:Qin X, Jiang X, Yuan Q, Xu G, He X. Optimal ablation index parameters for radiofrequency ablation therapy of atrial fibrillation. Pak J Med Sci. 2022;38(3):---------. doi: https://doi.org/10.12669/pjms.38.3.4971 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Impact of cavotricuspid isthmus depth on the ablation index for successful first-pass typical atrial flutter ablation

Cavotricuspid isthmus (CTI) linear ablation has been established as the treatment for typical atrial flutter. Recently, ablation index (AI) has emerged as a novel marker for estimating ablation lesions. We investigated the relationship between CTI depth and ablation parameters on the procedural results of typical atrial flutter ablation. A total of 107 patients who underwent CTI ablation were retrospectively enrolled in this study. All patients underwent computed tomography before catheter ablation. From the receiver-operating curve, the best cut-off value of CTI depth was < 4.1 mm to predict first-pass success. Although the average AI was not different between deep CTI (DC; CTI depth ≥ 4.1) and shallow CTI (SC; CTI depth < 4.1), DC required a longer ablation time and showed a lower first-pass success rate (p < 0.01). In addition, the catheter inversion technique was more frequently required in the DC (p < 0.01). The lowest AI sites of the first-pass CTI line were determined in both the ventricular (2/3 segment of CTI) and inferior vena cava (IVC, 1/3 segment of CTI) sides. The best cut-off values of the weakest AIs at the ventricular and IVC sides for predicting first-pass success were > 420 and > 386, respectively. Among patients with these cut-off values, the first-pass success rate was 89% in the SC and 50% in the DC (p < 0.01). Although ablation parameters were not significantly different, the first-pass success rate was lower in the DC than in the SC. Further investigation might be required for better outcomes in deep CTIs.

Factors associated with the efficacy of atrial fibrillation radiofrequency catheter ablation: opinion of the specialists who use the “Ablation Index” module

This document provides an overview of current problems and trends in the catheter ablation of atrial fibrillation, summarizes the opinions of specialists, obtained during a web-based electronic survey, on aspects and parameters of radiofrequency ablation. The approaches on improving the efficacy and safety of radiofrequency catheter ablation of atrial fibrillation are provided.

Myocardial injury after pulmonary vein isolation: fire versus ice

Introduction The cornerstone of atrial fibrillation (AF) catheter ablation is pulmonary vein isolation (PVI), either using point-by-point radiofrequency ablation (RF) or single-shot ablation devices, such as cryoballoon ablation (CB). However, achieving permanent transmural lesions is difficult and pulmonary vein (PV) reconnection is common. Elevation of high-sensitivity Troponin I (hsTnI) may be used as a surrogate marker for transmural lesions. Still, data regarding the comparison of hsTnI increase after PVI with RF or cryo-energy is controversial. Purpose The aim of this study is to compare the magnitude of hsTnI elevation after PVI with CB versus RF using ablation index guidance. Methods Prospective study of 60 patients admitted for first ablation procedure of paroxysmal or persistent AF in a single tertiary Cardiology Department. Thirty patients were submitted to PVI using CB and 30 patients were submitted to RF, using CARTO® mapping system and ablation index guidance. Patients with atrial flutter were excluded. Baseline characteristics were compared between groups, as well as hsTnI before and after the procedure. Results Mean age was 57.9±12.3 years old, 62% of patients were male and 77% had paroxysmal AF. There were no significant differences between groups regarding gender, age, prevalence of hypertension, dyslipidaemia, diabetes, obesity or AF type. There was also no significant difference in electrical cardioversion need during the procedure. HsTnI median value before ablation was 1.90±1.98 ng/dL. Postprocedural hsTnI was significantly higher in CB-group (6562.7±4756.2 ng/dL versus 1564.3±830.7 ng/dL in RF-group; P=0.001). Regarding periprocedural complications, there was only one case of mild pericardial effusion in RF-group associated with postablation hsTnI of 1180.0 ng/dL. Conclusions High-sensitivity Troponin I was significantly elevated after PVI, irrespective of the ablation technique. In CB-group, hsTnI elevation was significantly higher than in RF-group. This disparity may reflect more extensive lesions with cryoablation, without compromising safety. Longterm studies are needed to understand whether this hsTnI elevation is predictive of a lower AF recurrence rate. FUNDunding Acknowledgement Type of funding sources: None.