Search

A cavotricuspid isthmus pouch can be a breakout site for gap conduction of cavotricuspid isthmus block line. If the previous block line is electrically silent, high‐density 3‐D mapping and pouchgraphy are useful to find the pouch and ablate within it.

We herein report a 79-year-old man with recurrent atrial flutter (AFL) following catheter ablation for pulmonary vein (PV) isolation and block line of the cavotricuspid isthmus. An electrophysiological study and three-dimensional mapping results revealed left atrium (LA)-PV macroreentrant flutter caused by a conduction gap, possibly correlated to prior application, which mimicked cavotricuspid isthmus-dependent AFL. This LA-PV flutter was terminated after applying radiofrequency to the gap at the antrum near the bottom left inferior PV in the posterior LA wall. During follow-up, the patient did not present with atrial tachyarrhythmias; antiarrhythmic drugs were therefore not administered.

In patients with cavotricuspid isthmus (CTI)-dependent atrial flutter, ablation along the CTI is often a routine and straightforward procedure. However, certain aspects of the regional anatomy can pose technical challenges such that bidirectional block across the CTI can be difficult to achieve.1 Using a case example, we review common challenges with CTI ablation, discuss the important anatomic considerations that are relevant to procedural difficulty, and present approaches to troubleshooting.

This report discusses the mapping of an incomplete cavotricuspid isthmus flutter line with a high-density mapping catheter to visualize the arrhythmogenic substrate responsible for incomplete block. The relevant signals were unapparent when using a traditional ablation catheter but were evident with application of a high-density mapping catheter. High-density mapping holds promise for recording electrograms in gaps in other ablation lesion sets that may not be able to be easily identified using more traditional equipment alone.

Introduction and objectives: This report presents the findings of the 2018 Spanish Catheter Ablation Registry. Methods: Data collection was retrospective. A standardized questionnaire was completed by each of the participating centers. Results: Data sent by 100 centers were analyzed, with a total number of 16,566 ablation procedures performed (the highest historically reported in this registry) for a mean of 165.5 ± 127.9 and a median of 119 procedures per center. The ablation targets most frequently treated were atrial fibrillation (n = 4234; 25.6%), atrioventricular nodal re-entrant tachycardia (n = 3525; 21.3%) and cavotricuspid isthmus (n = 3425; 20.7%). A new peak was observed in the ablation of atrial fibrillation, increasing the distance from the other substrates. The overall success rate was 91%. The rate of major complications was 2.2%, and the mortality rate was 0.04%. A total of 2.1% of the ablations were performed in pediatric patients. Conclusions: The Spanish Catheter Ablation Registry systematically and continuously enrolls the ablation procedures performed in Spain, showing a progressive increase in the number of ablations over the years, with a high success rate and low percentage of complications.

Background Radiofrequency (RF) catheter ablation is one of the most common strategies for the current management of cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL). The interindividual anatomic variability can influence the duration and outcome of ablation procedure. Objective The purpose of this study was to establish complication rates in patients undergoing RF catheter ablation for CTI-dependent AFL, assess the role of CTI morphology in procedural success, and determine the anatomic variability of CTI ex vivo. Methods RF catheter ablation for CTI-dependent AFL was performed in 337 consecutive patients. Angiographically determined CTI morphology was classified as either simple or complex due to pouchlike recesses. Macroscopic and histologic examination of the CTI was performed in 104 heart specimens from consecutive autopsies. Results Complex CTI anatomy was present in 10.9% of AFL patients. RF application time to achieve bidirectional isthmus block was longer in patients showing pouchlike recesses than in those without (10.7 vs 8.3 min; P= .025). Acute procedure failure or major complications occurred in 3 cases, all with complex CTI anatomy. A pouchlike recess of the CTI was present in 9.6% of autopsy hearts. Histomorphometric analysis of the CTI atrial wall demonstrated that the central level was the thinnest in the 3 sectors and the paraseptal level was the thickest. Conclusion Although RF catheter ablation is a safe and effective procedure for AFL treatment, CTI anatomic complexity can affect ablation parameters and outcome. Standard definition of CTI morphologic variants is recommended. Preprocedural assessment of CTI anatomy might lead to personalized ablation preventing potential difficulties and complications.

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 p p 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

The treatment of atrial flutter (AFL) in patients without structural heart disease (SHD) by transcatheter radiofrequency ablation of the cavotricuspid isthmus (CTI) and bilateral pulmonary veins has achieved good results. We report three cases of typical AFL treated by surgical radiofrequency ablation. One patient, without SHD, successfully underwent CTI ablation and cardioversion. The other two patients, with SHD, underwent CTI ablation, partial right atrial ablation and pulmonary vein isolation, but a normal sinus rhythm was not achieved. Therefore, standard maze IV surgery may be the best choice in patients with AFL and SHD.

Background We evaluated the differences in the anatomy of the cavotricuspid isthmus (CTI) by assessing image loops provided by intracardiac echocardiography (ICE) in patients who underwent ablation for atrial flutter and/or atrial fibrillation. Purpose CTI is an essential component of the reentrant circle in isthmus–dependent atrial flutter (CTI-AFL) and a target for catheter ablation. In some patients, CTI anatomy may be responsible for a difficult procedure. The aim of this study is to describe in details the anatomical variants of this structure. Methods We included a group of 138 patients, who underwent cardiac ablation for atrial flutter and/or atrial fibrillation between August 2020 and January 2021. Intracardiac echocardiography was employed during the intervention to evaluate the morphology of CTI. Analysis was focused on size, shape, presence of sub-eustachian pouch (excavation more than 5 mm) or presence of prominent Eustachian ridge (ER, embryologic remnant of the valve of the IVC) and mobility of the structure. Results The length of CTI measured during ventricular systole averaged at 38,4mm (min 22,5mm, max 60mm). The most frequent pattern was a flat CTI without sub-eustachian excavation or with excavation less than 5mm (71 patients; 51.4%). A pouch (excavation more than 5mm) was observed in 41 pts (29.7%), where the deepest pouch reached 10,5mm. Prominent ER was present in 58 pts (42%). The remaining 26 of CTIs (18.8%) were classified in the “unclassifiable” category with deviations from common anatomic variants - substantial convexity, pronounced trabeculation of isthmus or double pouch. We observed 14 CTIs (10.1%), where the structure was partially or in full extent detached from the diaphragm, sliding during cardiac contractions. In addition to the described morphology, Chiari's network was observed in 18 pts (13%). In reference to mobility, 53 pts (38.4%) presented with hypermobile CTI with a difference in size of more than 1/3 between the diastole and systole. Moreover, we looked into differences of CTI related to BMI, left atrial volume index (LAVi) and ejection fraction of the left ventricle. A positive correlation was found between LVEF and mobility of CTI. Hypermobile CTI was present in 42.2% of pts with normal LVEF compared to only 18.9% of pts with reduced EF (EF less than 50%). Similar results were observed in pts with non-dilated LA, where hypermobile CTI was present in 51.9% of pts compared to only 35.1% of pts with dilated LA with LAVi >28 ml/m2 (see table below). Conclusions We observed a substantial differences in the anatomy of the CTI, which could play an important role in catheter ablation of this structure. Besides the prominent ER, significant sub-eustachian pouch and hypermobility appear to be variants predisposing to difficult ablation. Funding Acknowledgement Type of funding sources: None. CTI variants related to EFLV, BMI, LAViCTI detached from the diaphragm

Purpose Based on the high rate of coexisting atrial fibrillation (AF) and atrial flutter (AFL), prophylactic cavotricuspid isthmus ablation (CTIA) adjunctive to AF ablation has recently been attempted in patients with AF and without AFL. The present study aimed to determine the rates of AFL occurrence and CTI reconduction after performing CTI ablation adjunctive to AF ablation. Methods We analyzed the data of 3833 consecutive patients with AF, who underwent prophylactic CTIA with AF ablation between 2009 and 2020. Results In all patients, CTIA and AF ablations were successful. Clinical AFL occurred in seven patients (0.18%, 7/3,833), and the observed rate was lower than those reported for cases of AF ablation without CTIA and for those of CTIA for pure AFL. A second ablation was needed in 745 patients at a median of 253 days (25 and 75 percentiles, 116 and 775 days) after the first ablation. In 12.1% (90/745) of the patients, CTI reconduction was observed. The reconduction rate was lower than that previously reported for CTIA for pure AFL. Conclusions The present retrospective study found acceptably low rates of clinical AFL occurrence and CTI reconduction following prophylactic CTIA performed with AF ablation, which was supported by the findings obtained after performing a comparison of the rates with those of other ablations (AF ablation only and CTIA for pure AFL). Considering the high correlation between AF and AFL, the present study provided information regarding the efficacy of adjunctive CTIA.

Background An RFA lesion quality indicator, Surpoint Tag Index® (TI) incorporates key factors: power, time, and contact force, impacting lesion quality. TI accurately estimates lesion depth in animal studies. However, the relationship between TI and in‐vivo atrial wall thickness in patients exhibiting bidirectional block remains unknown. Objective To describe the relationship between atrial wall thickness and TI in CTI exhibiting bidirectional block. Methods Data from 492 RFA lesions from 25 patients undergoing PVI and CTI ablations in SR with point‐by‐point RF lesions (30 min. Results In lesions exhibiting bidirectional block, the thinnest (1–2 mm; 5% lesions) and thickest (8–10 mm; 6% lesions) portions of the CTI correlated with the lowest (429 ± 75) and highest (516 ± 64) TI. The bulk of thickness (2–6 mm; 80%) correlated with a TI of 455 ± 72 (p = 0.001). There was a weak but positive correlation between TI and CTI thickness (r = 0.2; p ≤ 0.01). Examined in sectors, the anterior 1/3rd CTI was the thickest (4.8 ± 1.9 mm) but correlated with a similar TI value (479 ± 75 vs. 471 ± 70; p = 0.34) as the thinner middle 1/3rd (3.8 ± 1.7 mm; p ≤ 0.0001). Conclusion A mean TI value of 455 correlates with bidirectional block across the bulk of CTI with lower and higher values needed for the thinner and thicker portions, respectively. Tissue composition, aside from wall thickness, influences TI values for the creation of the bidirectional block.

Background: Whether unidirectional conduction block (UB) can be observed after creation of a radiofrequency (RF) line is still debated. Previous studies reported a prevalence of 9 to 33% of UB, but the assessment was performed using a point-by-point recording across the line. Ultra-high-density (UHD) system may bring some new insights on the exact prevalence of UB. Purpose: A prospective study was conducted to assess the prevalence of UB and bidirectional block (BB) using UHD system after RF line creation. Methods: Patients referred for atrial RF ablation procedure were included in this multicenter prospective study. UHD maps were performed by pacing both sides of the created line. Results: A total of 80 maps were created in 40 patients (67 ± 12 years, 70% male) by pacing (mean cycle length 600 ± 57 ms) from both sides of the cavotricuspid isthmus line. After a 47 ± 17 min waiting time after the last RF application, UHD maps (mean number of 4842 ± 5010 electrograms, acquired during 6 ± 5 min) showed that BB was unambiguously confirmed on all of them. UB was not observed in any map. After a mean follow-up of 12 ± 4 months, 6 (14%) patients experienced an arrhythmia recurrence. Conclusion: After creation of an RF line, no case of UB was observed using UHD mapping, suggesting that the presence of a conduction block along a RF line is always associated with a block in the opposite direction.

A 43-year-old woman presented with recurrent symptomatic, multidrug refractory atrial fibrillation (AF) and atrial flutter (AFL). Three prior ablation strategies consisted of pulmonary vein isolation, cavotricuspid isthmus line, anterior mitral line, and posterior box lesion set. She provided

To detect detouring gap conduction, as demonstrated in this case, 3‐D mapping is useful in addition to conventional methods.

A 70-year-old woman was admitted for end-stage heart failure and cardiogenic shock, which required the implantation of a left ventricular assist device (LVAD, Heartmate 3, Abbott, St. Paul, MN, USA) as a bridge to transplant. During the hospital stay, she presented two episodes of paroxysmal complete atrioventricular block with prolonged asystole. No regular pacemaker could be implanted because of infectious contraindications and vascular access limitations. As a consequence, a leadless pacemaker was implanted and programmed in backup VVI mode at 50 bpm. This article is protected by copyright. All rights reserved.

Background Ablation index (AI) has been evaluated as guidance quality marker for pulmonary vein isolation, but not for linear ablation of the cavotricuspid isthmus (CTI) for typical right atrial flutter (AFL). We thus studied the feasibility and effectiveness of AI-guided CTI for AFL. Methods Procedural and 6-month outcomes of ablation for AFL were retrospectively compared between consecutive patients undergoing either AI-guided ablation of CTI (n = 43; AI target of 500 for anterior 2/3 segments and 400 for posterior 1/3 segments) or contact force (CF)-guided ablation (n = 42) at a single center. Each Visitag dataset from all patients in each group was analyzed. Results AI guidance vs CF guidance was associated with: higher first-pass conduction block of CTI (93.0% vs 76.2%, P = .03) with similar ablation time; similar acute spontaneous CTI reconnection 2.3% vs 9.5%, P = .343); fewer radiofrequency (RF) applications (10.1 ± 2.8 vs 11.5 ± 3.0, P = .031) needed to achieve CTI directional block; significantly higher mean ablation time, impedance drop, force time integral and AI and similar mean CF and power of each VisiTag point. One inguinal hematoma and one pseudoaneurysm developed in the AI and CF groups, respectively. Recurrent AFL was recorded in two (4.7%) AI-group patients and four (9.5%) CF-group patients (P = .650). Conclusion AI-guided ablation of CTI line for AFL appears feasible and effective with similar ablation time, fewer RF applications, a higher rate of first-pass conduction block, and no additional complications.

AIMS Pulmonary vein isolation (PVI) is an effective procedure for atrial fibrillation (AF). The role of additional cavotricuspid isthmus (CTI) block ablation remains controversial in AF patients without atrial flutter (AFL). Therefore, this study aimed to explore the clinical outcome of additional CTI block ablation in patients without AFL. METHODS Between January 2013 and December 2017, a total of 139 patients who did not have documented AFL and who underwent catheter ablation for AF were recruited. Fifty-seven patients were classified in additional CTI block ablation group and 82 patients were classified in without CTI group. The incidence of early-onset and late-onset atrial arrhythmia recurrence was compared between the two groups. RESULTS The additional CTI group had a higher prevalence of persistent or long-standing AF and larger left atrial volume. The additional CTI group had a higher incidence of late-onset atrial arrhythmia recurrence (38.6% vs 12.2%; P

Atrial lead implantation commonly constitutes a technical problem, especially in patients with improper structure of the right atrium. The atrial lead displacement requires reimplantation, what creates a risk of infection and periprocedural complications, particularly in patients with the heart failure. To minimise the risk of complications, it is essential to asses potential difficulties before the procedure. The article concerns the patient with many burdens (right and left ventricular systolic dysfunction, tricuspid valve regurgitation, paroxysmal atrial fibrillation and atrial flutter, catheter ablation of both types of the arrhythmias, CRT device implantation), who was repeatedly hospitalized due to atrial lead displacement and who underwent implantation of Medtronic SelectSecure 3830 lead, what finally provided to stable placement of the lead in the right atrium.

PURPOSE: Radiofrequency (RF) catheter ablation is widely accepted as a first-line therapy for cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL). The novel DiamondTemp (DT) catheter with temperature feedback during RF ablation has been released recently on the market. The purpose of this study was to evaluate the impact of DiamondTemp (DT) technology on ablation efficiency during AFL. METHODS: In this single-center study, 30 consecutive patients with typical AFL indicated to ablation of CTI were included. The first 15 patients underwent CTI ablation using 8-mm tip catheter, and the following 15 patients underwent temperature-controlled RF ablation using DT catheter. The endpoints were number and mean total duration of RF applications, mean temperature reached in the setting of CTI, procedural times, and fluoroscopy times. RESULTS: There were no significant differences between the two groups concerning baseline characteristics. Mean duration of the each application (71.5 s ± 30.6 vs 12.4 s ± 13.2, p value

BACKGROUND Anatomical studies demonstrate significant variation in cavotricuspid isthmus (CTI) architecture. METHODS Thirty-eight patients underwent CTI ablation at two tertiary centers. Operators delivered 682 lesions with a target ablation index (AI) of 600 Wgs. Ablation parameters were recorded every 10-20 ms. Post hoc, Visitags were trisected according to CTI position: inferior vena cava (IVC), middle (Mid), or ventricular (V) lesions. RESULTS There were no complications. 92.1% of patients (n = 35) remained in sinus rhythm after 14.6 ± 3.4 months. For the whole CTI, peak AI correlated with mean impedance drop (ID) (R2 = 0.89, p

Background: Contact force (CF) and related parameters have been evaluated as an effective guide mark for pulmonary vein isolation, yet not for linear ablation of the cavotricuspid isthmus (CTI) dependent atrial flutter (AFL). We thus studied the efficacy and safety of CF related parameter-guided ablation for CTI-AFL., Methods: Systematic search was performed on databases involving PubMed, EMbase, Cochrane Library and Web of Science (through June 2022). Original articles comparing CF related parameter-guided ablation and conventional parameter-guided ablation for CTI-AFL were included. One-by-one elimination, subgroup analysis and meta-regression were used for heterogeneity test between studies., Results: Ten studies reporting on 761 patients were identified after screening with inclusion and exclusion criteria. Radiofrequency (RF) duration was significantly shorter in CF related parameter-guided group ( p = 0.01), while procedural time ( p = 0.13) and fluoroscopy time ( p = 0.07) were no significant difference between two groups. CF related parameter-guided group had less RF lesions ( p = 0.0003) and greater CF of catheter-tissue ( p = 0.0002). Touch-up needed after first ablation line was less in CF related parameter-guided group ( p = 0.004). In addition, there were no statistical significance between two groups on acute conduction recovery rates ( p = 0.25), recurrence rates ( p = 0.92), and complication rates ( p = 0.80). Meta-regression analysis revealed no specific covariate as an influencing factor for above results ( p > 0.10)., Conclusion: CF related parameters guidance improves the efficiency of CTI ablation, with the better catheter-tissue contact, the lower RF duration and the comparable safety as compared with conventional method, but does not improve the acute success rate and long-term outcome., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Pang, Gao, Zhang, Guo and Wang.)

Introduction Multiple contact-based ablation technologies have been developed to allow real-time judgement of lesion effectiveness; local impedance (LI) guided ablation and the role of ultra-high density (UHD) mapping have not yet been evaluated for cavotricuspid isthmus dependent atrial flutter (CTI-AFL). Methods This non-randomised observational study evaluated patients undergoing CTI-AFL ablation using conventional, contact force (CF) and LI guided strategies. Ablation metrics were collected, and in the LI cohort, the use of UHD mapping for breakthrough was evaluated. Results 30 patients were included, 10 in each group. Mean total ablation time was significantly shorter with LI (3.2±1.3min) vs conventional (5.6±2.7min) and CF (5.7±2.0min, p=0.0042). Time from start of ablation to CTI block was numerically shorter with LI (14.2±8.0min) vs conventional and CF (19.7±14.1 and 22.5±19.1min, p=0.4408). There were no differences in the number of lesions required to achieve block, procedural success, complication rates or recurrence. 15/30 patients did not achieve block following first-pass ablation. UHD mapping rapidly identified breakthrough in the 5 LI patients, including epicardial-endocardial breakthrough (EEB) away from the line. Conclusion The use of LI for real-time assessment of lesion formation resulted in significantly less ablation requirement. UHD mapping rapidly identified breakthrough, including EEB, which would likely have been difficult to identify otherwise and possibly require extensive ablation, contributing towards shortening of time to CTI block with LI.

Any atrial flutter which is cavotricuspid isthmus dependent is typical AFL and creation a line of RFA in CTI is the ablation strategy.

Introduction: Macro-reentrant arrhythmias involving the cavo-tricuspid isthmus (CTI) are common in patients with atrial fibrillation (AF). Bidirectional CTI block is the ablation strategy of choice, but it can be surprisingly difficult to obtain at times. Objective: Aim of this study was to systematically assess the characteristics of the CTI to determine its most common anatomical variants to be anticipated for ablation. Methods: This is a prospective observational study in which intracardiac echocardiography (ICE) was used to visualize the CTI of patients undergoing AF ablation. The presence of anatomical variants was recorded, and length was measured along the central CTI in atrial systole. CTI systolic shortening measured in sinus rhythm and defined as: [(diastolic length - systolic length)/(diastolic length)]x100. Results: 180 patients (65±9 years old, 31% female, 37% paroxysmal AF) are included in the study. Mean CTI length was 31±9 mm, with a systolic shortening of 25±13%. A prominent Eustachian ridge was present in 32%, a Chiari network in 11%, and at least one pouch-like recess in 35%, with a mean depth of 5.3±2.5 mm (Figure). A longer CTI was observed in patients with non-PAF compared with patients with PAF (33 vs. 27 mm, P Conclusion: Anatomical variants of the CTI are common and should be anticipated in case of a challenging CTI ablation. A long CTI is associated with OSA and might warrant further clinical screening to identify this common AF comorbidity. CTI systolic shortening correlates with the type of AF and could represent a measure of right atrial contractility.

Introduction Radiofrequency ablation of the cavotricuspid isthmus is currently the first-choice treatment of typical atrial flutter and usually it is performed electively. The purpose of this study was to see whether performing on-line ablation has similar clinical results compared to the conventional strategy. Methods Consecutive patients (465) who underwent ablation of the cavotricuspid isthmus for typical AFL at our electrophysiology laboratory in the 2008-2017 decade were studied. We evaluated the acute and long-term clinical outcomes of those who were treated electively (337) compared to those who had online ablation (128), that is within 24 hours of presenting to the Cardiology department. In patients treated on an emergency basis, a transoesophageal echocardiogram was performed to rule atrial thrombi when needed. Results No significant intraprocedural difference was observed between the 2 patient groups, with comparable acute electrophysiological success (99% vs 98%) and serious complications. Even at the subsequent 4-year follow-up, there were no significant differences in the recurrence of typical AFL, onset of AF and other clinical events. Conclusions Online ablation of typical atrial flutter performed at the time of the clinical presentation of the arrhythmia, was shown to be comparable in terms of procedural safety and clinical efficacy in the short and long term compared to an elective ablation strategy.