Treatment Of Typical Atrial Flutter Research Articles

Feasibility and safety of cavotricuspid isthmus ablation using exclusive intracardiac echocardiography guidance: a proof-of-concept, observational trial

Abstract Introduction Catheter ablation is the preferred treatment for typical atrial flutter (AFl), although it can pose challenges due to anatomical abnormalities. The integration of 3D electroanatomical mapping systems (EAMS) has notably diminished the need for fluoroscopy in AFl ablation procedures. Intracardiac echocardiography (ICE) has also demonstrated advantages in reducing radiation exposure during AFl ablation. Nevertheless, there is a lack of evidence on the feasibility of ICE-guided, zero-fluoroscopy AFl ablation without the use of EAMS. Methods In this prospective study, we enrolled 80 patients with CTI-dependent AFl. The initial 40 patients underwent ablation guided by standard fluoroscopy along with ICE (Standard ICE group), whereas the remaining 40 patients underwent zero-fluoroscopy ablation exclusively using ICE (Zero ICE group). Procedure outcomes, including acute success, procedural duration, fluoroscopy duration, radiation dose, and any associated complications, were compared between the groups. Results Both groups achieved a 100% acute success rate. In the Zero ICE group, the zero-fluoroscopy approach was successfully executed in 39 out of 40 cases (97.5%). There were no significant differences in procedure time (55.5 (46.5; 66.8) min vs. 51.5 (44.0; 65.5), p=0.50) and puncture to first ablation time (18 (13.5; 23) min vs. 19 (15; 23.5) min, p=0.50) between the groups. The Zero ICE group had significantly lower fluoroscopy time (57 (36.3; 90) sec vs. 0 (0; 0) sec, p<0.001) and dose (3.17 (2.27; 5.63) mGy vs. 0 (0; 0) mGy, p<0.001 compared to the Standard ICE group. Total ablation time was longer in the Standard ICE group (597 (447; 908) sec vs. 430 (260; 750), p=0.02), but total ablation energy (22458 (14836; 31116) Ws vs. 17043 (10533; 29302) Ws, p=0.10) did not differ significantly. First-pass bidirectional conduction block of the CTI and acute reconnection rates were comparable between the groups. No complications or recurrences were noted during the follow-up period. Conclusion ICE-guided, zero-fluoroscopy CTI ablation for AFl using only ICE is feasible and safe. This method effectively eliminates radiation exposure without compromising procedural duration, total ablation time, or acute success rates.isthmus ablation by ICE

Optimizing outcomes in catheter ablation for typical atrial flutter: a comparative study of intracardiac echocardiography versus fluoroscopy guidance

Abstract Background Catheter ablation is a standard intervention for typical atrial flutters, specifically targeting the cavotricuspidal isthmus (CTI). Intracardiac echocardiography (ICE) plays a pivotal role in providing real-time visualization of anatomical structures during the electrophysiology procedure, thereby enhancing safety and potentially reducing reliance on fluoroscopy, leading to improved procedural outcomes. We aimed to conduct a comparative analysis of procedural and follow-up outcomes between ICE-guided and fluoroscopy-only guided catheter ablations for CTI in patients undergoing treatment for typical atrial flutter. Methods A retrospective analysis was conducted at our university center, encompassing 376 consecutive patients in a single-center study. Of these, 158 underwent procedures guided solely by fluoroscopy, while 218 received ICE-guided CTI ablation. Results ICE-guidance demonstrated a statistically significant reduction in fluoroscopy time (72 [36; 170] s vs. 888 [578; 1184] s; p<0.01), total procedure time (70 [52; 90] min vs. 90 [60; 105] min; p<0.01), total ablation time (692 [435; 998] s vs. 920 [629; 1373] s; p<0.01), and the duration from the first to last ablation (20.5 [12; 37] min vs. 41.0 [26.8; 59.3] min; p<0.01). Both groups achieved a 100% acute success rate without major complications. The ICE-guided group exhibited a significantly superior long-term success rate (ICE-guided group: 95.74%, fluoroscopy-only group: 89.26%; p=0.048) compared to the fluoroscopy-only group at an average follow-up length of 34 months. Conclusion The utilization of ICE-guidance for CTI ablation significantly reduces fluoroscopy exposure, procedure time, and ablation time, ultimately contributing to enhanced long-term success rates when compared to the conventional fluoroscopy-only approach.

Cryoballoon pulmonary vein isolation as first-line treatment of typical atrial flutter: long-term outcomes of the CRAFT trial.

CRAFT was an international, multicentre, randomised controlled trial across 11 sites in the United UK and Switzerland. Given the evidence that pulmonary vein triggers may be responsible for atrial flutter (AFL) as well as atrial fibrillation (AF), we hypothesised that cryoballoon pulmonary vein isolation (PVI) would provide greater symptomatic arrhythmia reduction than cavotricuspid isthmus (CTI) ablation, whilst also reducing the subsequent burden of AF. Twelve-month outcomes were previously reported. In this study, we report the extended outcomes of the CRAFT study to 36months. Patients with typical AFL and no evidence of AF were randomised 1:1 to cryoballoon PVI or radiofrequency CTI. All patients received an implantable loop recorder (ILR) for continuous cardiac rhythm monitoring. The primary outcome was time-to-symptomatic arrhythmia recurrence > 30s. Secondary outcomes included time-to-first-AF episode ≥ 2min. The composite safety outcome included death, stroke and procedural complications. A total of 113 patients were randomised to cryoballoon PVI (n = 54) or radiofrequency CTI ablation (n = 59). Ninety-one patients reconsented for extended follow-up beyond 12months. There was no difference in the primary outcome between arms, with the primary outcome occurring in 12 PVI vs 11 CTI patients (HR 0.97; 95% CI 0.43-2.20; p = 0.994). AF ≥ 2min was significantly less frequent in the PVI arm, affecting 26 PVI vs 36 CTI patients (HR 0.48; 95% CI 0.29-0.79; p = 0.004). The composite safety outcome occurred in 5 PVI and 6 CTI patients (p = 0.755). Cryoballoon PVI shows similar efficacy to radiofrequency CTI ablation in reducing symptomatic arrhythmia recurrence in patients presenting with isolated typical AFL but significantly reduces the occurrence of subsequent AF.

Paradoxical interatrial conduction recovery after cavotricuspid isthmus ablation: A case report

We present a case of a patient with advanced interatrial block who was admitted for cavotricuspid isthmus ablation as treatment of typical atrial flutter. A baseline advanced interatrial block pattern turned into partial interatrial block pattern and prolonged PR interval after the procedure. We discuss the mechanism underlying that change.

Abstract 15828: Variations in the Use of Catheter Ablation for Atrial Flutter Among US Adults Using Nationwide Inpatient Sample (NIS) Database

Introduction: Atrial flutter is one of humans' most common cardiac arrhythmias. Catheter ablation is the definitive treatment for typical atrial flutter because of a very high success (>95%) and low complication rate. Therefore, we explored variations in the use of catheter ablation for atrial flutter among US adults. Methods: We used the 2017-2019 National Inpatient Sample (NIS) for this analysis. Multivariable logistic regression analysis was used to assess factors associated with catheter ablation among patients with atrial flutter in the US. Results: Of the 1406220 adults hospitalized with a diagnosis of atrial flutter, 66825 (4.75%) underwent ablation for atrial flutter. Blacks were less likely to undergo ablation for atrial flutter compared to Whites (AOR=0.91; 95% CI: 0.85-0.99, P = 0.01). Similarly, patients with Medicare (AOR=0.88; 95% CI: 0.83-0.92, P=0.00), and Medicaid insurance (AOR=0.80; 95% CI: 0.74-0.87, P=0.00) were less likely to have catheter ablation for aflutter compared to those with private insurance. Other significant predictors of the likelihood of getting an ablation included younger age 0.98 (95% CI: 0.97-0.98, P=0.00), and lower co-morbidity burden ( class II with AOR of 0.65; 95% CI: 0.62-0.69 and Class III with AOR of 0.43; 95% CI: 0.41-0.46 compared to class I). No gender disparity was observed in this analysis, females had an AOR of 0.96 (95% CI: 0.92-1.00) Conclusions: Findings highlight significant racial and insurance-related disparities in access to catheter ablation for atrial flutter. Addressing social and structural issues underlying these disparities is critical for achieving equitable outcomes for patients with atrial flutter.

Feasibility and safety of cavotricuspid isthmus ablation using exclusive intracardiac echocardiography guidance: a proof-of-concept, observational trial.

Catheter ablation is the preferred treatment for typical atrial flutter (AFl), but it can be challenging due to anatomical abnormalities. The use of 3D electroanatomical mapping systems (EAMS) has reduced fluoroscopy exposure during AFl ablation. Intracardiac echocardiography (ICE) has also shown benefits in reducing radiation exposure during AFl ablation. However, there is a lack of evidence on the feasibility of ICE-guided, zero-fluoroscopy AFl ablation without the use of EAMS. In this prospective study, we enrolled 80 patients with CTI-dependent AFl. The first 40 patients underwent standard fluoroscopy + ICE-guided ablation (Standard ICE group), while the other 40 patients underwent zero-fluoroscopy ablation using only ICE (Zero ICE group). Procedure outcomes, including acute success, procedure time, fluoroscopy time, radiation dose, and complications, were compared between the groups. The acute success rate was 100% in both groups. Out of the 40 cases, the zero-fluoroscopy strategy was successfully implemented in 39 cases (97.5%) in the Zero ICE group. There were no significant differences in procedure time [55.5 (46.5; 66.8) min vs. 51.5 (44.0; 65.5), p = 0.50] and puncture to first ablation time [18 (13.5; 23) min vs. 19 (15; 23.5) min, p = 0.50] between the groups. The Zero ICE group had significantly lower fluoroscopy time [57 (36.3; 90) sec vs. 0 (0; 0) sec, p < 0.001] and dose [3.17 (2.27; 5.63) mGy vs. 0 (0; 0) mGy, p < 0.001] compared to the Standard ICE group. Total ablation time was longer in the Standard ICE group [597 (447; 908) sec vs. 430 (260; 750), p = 0.02], but total ablation energy [22,458 (14,836; 31,116) Ws vs. 17,043 (10,533; 29,302) Ws, p = 0.10] did not differ significantly. First-pass bidirectional conduction block of the CTI and acute reconnection rates were similar between the groups. No complications or recurrences were observed during the follow-up period. Our study suggests that zero-fluoroscopy CTI ablation guided solely by ICE for AFl is feasible and safe. Further investigation is warranted for broader validation.

Outcome of the elective or online radiofrequency ablation of typical atrial flutter.

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. Consecutive patients (465) who underwent ablation of the cavotricuspid isthmus for typical atrial flutter (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 Department of Cardiology. In patients treated on an emergency basis, a transesophageal echocardiogram was performed to rule atrial thrombi when needed. 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 atrial fibrillation and other clinical events. 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.

Anticoagulation after typical atrial flutter ablation

The specifics of the anticoagulant therapy after radiofrequency ablation of the cavotricuspid isthmus have not been sufficiently studied, therefore, the recommendations for prescribing the anticoagulant therapy usually do not distinguish between atrial flutter and atrial fibrillation. In contrast to the case of atrial fibrillation, the effectiveness of the interventional treatment for typical atrial flutter reaches 90%. This procedure may save the patient from a long-term anticoagulant therapy in the absence of recurrence of typical atrial flutter. The decision to stop the anticoagulant therapy after successful radiofrequency ablation of the cavotricuspid isthmus should take into account the potential induction of atrial fibrillation in patients undergoing the interventional treatment. In addition to the CHA2DS2-VASc scale, which characterizes the patient's comorbidity, it is important to take into account the echocardiographic morphofunctional criteria to assess the risk of atrial fibrillation. Currently, this protocol is not regulated in the clinical guidelines. The analysis of the literature data and the authors' own experience allow us to conclude that the optimal time for stopping the anticoagulant therapy is a relapse-free period of 34 months after the radiofrequency ablation of the cavotricuspid isthmus, since it is at this time that the effectiveness of the interventional treatment can be objectified.

Cryoballoon Pulmonary Vein Isolation as First-Line Treatment for Typical Atrial Flutter

ObjectiveWe aimed to compare cryoballoon pulmonary vein isolation (PVI) with standard radiofrequency cavotricuspid isthmus (CTI) ablation as first-line treatment for typical atrial flutter (AFL).MethodsCryoballoon Pulmonary Vein Isolation as First-Line Treatment...

Effectiveness of various radiofrequency ablation catheters in the treatment of typical atrial flutter

Abstract Introduction Although ablation of typical atrial flutter (AFL) can be easily achieved with radiofrequency energy (RF), there are no studies that compare effectiveness of different ablation catheters. Our study aimed to compare the effectiveness of various types of ablation catheters in the treatment of AFL. Methods We analysed patients with AFL who underwent RF ablation by a single operator at our institution. Successful ablation was evidenced by presence of bidirectional conduction block (trans-isthmus conduction time ≥130 ms, or doubling of baseline conduction time, or presence of double potentials ≥90ms). Logistic regression was used to compare success rate and linear regression to compare lesion time. Results Out of the 222 patients, only 6 patients did not meet success criteria (2.7%). Catheters used were 8 mm tip in 16 patients, internally irrigated (Chili II Boston Scientific) in 47 patients, externally irrigated (non-force sensing) catheters (CoolPath, Abbott) in 40 patients. Externally irrigated force sensing catheter (Tacticath, Abbott) was used with &amp;gt;10 gm of force and (LPLD) setting (30W-45°C-60 sec) in 50 patients, and high-power short duration (HPSD) setting (50W-43°C −12 sec,) in 70 patients. No complications were encountered. Catheter type had no statistically significant association with ablation success. In terms of lesion time, HPSD catheter statistically significantly shortened lesion time by 758.3s, [CI −1128.29, −388.35s] followed by LPLD by 419.0s [CI −808.49, −29.47s]. Table 1 shows the lesion time difference for the catheters used as compared with 8 mm tip. Conclusions Typical atrial flutter radiofrequency ablation procedure had a high success rate, not influenced by type of ablation catheter. Contact force ablation catheter on HPSD is associated with shorter total lesion time. Funding Acknowledgement Type of funding sources: None.

Long term success of cavotricuspid isthmus ablation guided by the ablation index: results of the FLAI registry

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Cavotricuspid isthmus ablation (CTIA) is an effective treatment for typical atrial flutter (AFL) with a recurrence rate of about 10%. A prospective multicentric registry (FLAI registry) has recently shown that a protocol including ‘point by point’ CTI ablation targeting an a quality lesion marker (Ablation Index AI) ≥ 500 and a maximum inter-lesion distance (ILD) measurement of ≤6 mm allowed an acute success rate of 98.3%. In this study, we aimed to describe the incidence and predictors of recurrence of both AFL and atrial fibrillation (AF) in a long-term follow-up of the patients enrolled in the FLAI registry. Methods The FLAI registry was a multicentric non-randomized study that enrolled 412 consecutive patients (mean age 64.9±9.8; 72.1% males; 27.7% with structural heart disease). Patients with typical AFL underwent an AI-guided cavotricuspid isthmus ablation. The procedures targeted an AI of 500 and an ILD measurement of ≤ 6mm. The primary endpoints were CTI ‘first pass’ block and persistent block after a 20-minute waiting period. The CTI bidirectional "first pass block" was reached in 355 patients (88.3%), whereas CTI block at the end of the waiting period was achieved in 405 patients (98.3%). No complications were reported. The mean time of follow-up was 21±4.24 months and it was available for 397 patients. The FU included outpatient clinical evaluation, ECG and 24-h Holter ECG at three, six- and 12-months post-ablation, followed by an annual clinical evaluation and ECG. Documented ECG Atrial fibrillation events, in follow up, were also included in the data set. Results Atrial flutter recurrence: 22 AFL events were observed (5.5%) at 34 months. According to the Kaplan Meier analysis, the growth of recurrence rate was constant between 6 and 12 months, after 19 months recurrences were unlikely. At the univariate analysis predictors of AFL recurrence were: absence of bidirectional block after the waiting time period (p= 0,001); failure of the CTIA index procedure (p=&amp;lt;0,0005); ablation line lengths &amp;gt; 32 mm (p=0.,018), number of automatic ablation lesion tags (VISITAG) &amp;gt; 20 (p=0,.005) and At the increathe reported numbers of ‘g"gap’" in the ablation line lengths: the more the gaps increase the more the probability of AFL recurrence in FU increases (p=0.,037). In the Multivariate aAnalysis, the independent predictors of AFL recurrence were: the procedural success and the number of VISITAG (OR =1.062) Atrial fibrillation recurrence: 45 patients developed atrial fibrillation after CTI ablation (11.3%). In the multivariate analysis, the major independent predictor was a documented pre-procedural Afib and the risk increases with the younger age (&amp;lt; 53 yo). Conclusions The FLAI protocol is safe, reproducible and effective in the follow-up, with a long term success of 94,5%. The reported incidence of atrial fibrillation in FU was 11,3%

First clinical experience with cardiac magnetic resonance guided typical atrial flutter ablation with the integration of active catheter tracking and electro-anatomical mapping

Abstract Funding Acknowledgements Type of funding sources: None. Background In our university hospital, we previously implemented cardiac magnetic resonance (CMR) guided typical atrial flutter ablation in a pre-existing MRI suite which was transformed into an interventional cardiac MRI (iCMR) suite. Purpose To describe our first clinical experience with integration of active catheter tracking and dedicated electro-anatomical mapping (EAM) system for the treatment of typical atrial flutter in a transformed pre-existing MRI suite. Methods Between February 2021 and December 2021, all consecutive patients planned for CMR guided typical atrial flutter ablation were included in this analysis. The procedure was performed under general anaesthesia. Feasibility and safety of active catheter tracking and the integration with a dedicated EAM was evaluated. All patients provided written informed consent. Results In total, nine patients underwent CMR guided atrial flutter ablation. Procedural characteristics are presented in Table 1. In all patients, both active catheter tracking and the integration with EAM were performed successfully. Bidirectional cavo-tricuspid isthmus block was achieved in eight out of nine patients and confirmed by differential pacing using intracardiac electrograms and EAM. In one of these eight patients, the registration of intracardiac electrograms was not possible due to technical problems and the patient was transferred to a conventional electrophysiology lab to complete the ablation following our predefined bailout procedure. Seven out of nine patients were in sinus rhythm at the start of the procedure, one in nodal rhythm with atrial bigeminy, one patient required electrical cardioversion for atrial fibrillation prior to the procedure. No periprocedural complications occurred. Conclusion CMR guided typical atrial flutter ablation in a transformed pre-existing MRI suite using active catheter tracking and a dedicated EAM system is feasible and safe based on this small population. It allows for detailed visualisation of catheters and individual patients anatomy. Further studies in larger patient populations are required to evaluate whether iCMR is cost effective and can improve clinical outcome of typical atrial flutter ablation and other arrhythmias.

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.

Safety, efficacy, and reproducibility of cavotricuspid isthmus ablation guided by the ablation index: acute results of the FLAI study.

Ablation index (AI) is a marker of lesion quality during catheter ablation that incorporates contact force, time, and power in a weighted formula. This index was originally developed for pulmonary vein isolation as well as other left atrial procedures. The aim of our study is to evaluate the feasibility and efficacy of the AI for the ablation of the cavotricuspid isthmus (CTI) in patients presenting with typical atrial flutter (AFL). This prospective multicentre non-randomized study enrolled 412 consecutive patients with typical AFL undergoing AI-guided cavotricuspid isthmus ablation. The procedure was performed targeting an AI of 500 and an inter-lesion distance measurement of ≤6 mm. The primary endpoints were CTI 'first-pass' block and persistent block after a 20-min waiting time. Secondary endpoints included procedural and radiofrequency duration and fluoroscopic time. A total of 412 consecutive patients were enrolled in 31 centres (mean age 64.9 ± 9.8; 72.1% males and 27.7% with structural heart disease). The CTI bidirectional 'first-pass' block was reached in 355 patients (88.3%), whereas CTI block at the end of the waiting time was achieved in 405 patients (98.3%). Mean procedural, radiofrequency, and fluoroscopic time were 56.5 ± 28.1, 7.8 ± 4.8, and 1.9 ± 4.8 min, respectively. There were no major procedural complications. There was no significant inter-operator variability in the ability to achieve any of the primary endpoints. AI-guided ablation with an inter-lesion distance ≤6 mm represents an effective, safe, and highly reproducible strategy to achieve bidirectional block in the treatment of typical AFL.

Abstract 15689: Resistant Rapid Atrial Flutter With Left Atrial Thrombus: A Therapeutic Dilemma

Introduction: Electrical cardioversion (ECV) is highly successful in the treatment of typical atrial flutter (AFL). Patients with AFL with a rapid ventricular rate (RVR) of ≥150 beats per minute (BPM) and significant hemodynamic compromise benefit from urgent CV. This is a unique case of managing chemically resistance AFL with a left atrial (LA) thrombus. Case Presentation: A 48-year-old male with medical history of bioprosthetic mitral and aortic valve was admitted for new onset AFL with RVR. Patient complain of (c/o) progressively worsening dyspnea and chest palpitation from 3 days. The patient denied chest pain, dizziness, diaphoresis. On admission blood pressure (BP) was 122/80 mmHg with heart rate (HR) of 158 BPM. ECG showed 2:1 block AFL with RVR. Patient was started on IV heparin and diltiazem drip. However, as the HR remained &gt;150 and patient continued to c/o palpitations, IV amiodarone was added. The BP started to fall with the HR still &gt;150 BPM. An emergent TEE done showed LA thrombus. Hence, the ECV was not performed. Instead a synchronized (sync) 3-joule (J) shock on R wave was attempted to induce atrial fibrillation (AF), to achieve better rate control. Immediately after delivering the shock the cardiac rhythm was successfully converted to AF with HR of &lt;80 BPM. Discussion: LA thrombus and clinical thromboembolic events are highly prevalent in AFL. TEE is usually done to exclude thrombus in a patient with AFL for &gt;48 hrs and if presence of thrombus cannot be confidently excluded on TEE, CV should not be performed. As a shock provided during the relative refractory period (RRP) of the ventricle corresponding to the latter part of the T wave, can possibly induce ventricular fibrillation (the so-called “R-on-T Phenomenon”), with similar concept a low voltage sync shock on R wave, the RRP of the atria can possibly induce AF. AF can be more easily rate controlled on antiarrhythmics compared to AFL and a patient with LA thrombus on anticoagulants is at lower risk from embolic events in AF than SR. Conclusions: This clinical noninvasive maneuver may be useful and desired in the management of a deteriorating patient with AFL not responsive to chemical rate control and LA thrombus such as ours or for an instance when AF in a patient with LA thrombus was inadvertently converted to SR.

Outcome of the elective or online RF ablation of typical atrial flutter.

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. 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. 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. 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.

Cryoballoon pulmonary vein isolation as first line treatment for typical atrial flutter (CRAFT): study protocol for a randomised controlled trial

PurposeTreatment of typical atrial flutter (AFL) with cavo-tricuspid isthmus (CTI) ablation is associated with a high occurrence rate of new onset atrial fibrillation (AF) during follow-up. There are data to support the addition of pulmonary vein isolation (PVI) to CTI ablation in patients with both AF and AFL, but the role of cryoballoon PVI only, with no CTI ablation, in AFL patients with no prior documentation of AF has not been studied.MethodsCRAFT is an international, prospective, randomised, open with blinded assessment, multicentre superiority study comparing radiofrequency CTI ablation and cryoballoon PVI in patients with typical AFL. Participants with typical AFL are randomised in a 1:1 ratio to either treatment arm, with patients randomised to PVI not receiving CTI ablation. Post-procedural cardiac monitoring is performed using an implantable loop recorder. The primary endpoint is time to first recurrence of sustained symptomatic atrial arrhythmia. Key secondary endpoints include (1) total arrhythmia burden at 12 months, (2) time to first episode of AF lasting ≥ 2 min, (3) time to recurrence of AFL or AT and (4) procedural and fluoroscopy times. The primary safety endpoint is the composite of death, stroke/transient ischaemic attack, cardiac tamponade requiring drainage, atrio-oesophageal fistula, requirement for a permanent pacemaker, serious vascular complications requiring intervention or delaying discharge and persistent phrenic nerve palsy lasting > 24 h.ConclusionThis study compares the outcomes of 2 different approaches to typical AFL—the conventional ‘substrate’-based strategy of radiofrequency CTI ablation versus a novel ‘trigger’-based strategy of cryoballoon PVI.Trial registration(ClinicalTrials.gov ID: NCT03401099)

RIGHT CORONARY ARTERY INJURY FOLLOWING ATRIAL FLUTTER ABLATION: A RARE COMPLICATION

Radiofrequency ablation (RFA) of cavotricuspid isthmus (CTI) is the first line treatment of typical atrial flutter as it is very effective with a low risk of complications. Despite close anatomic proximity of RCA with cavotricuspid isthmus, right coronary artery (RCA) occlusion is a rarely reported

P2845Recurrent atrial flutter and incidence of atrial fibrillation ablation after first-time ablation for typical atrial flutter: a nation-wide Danish cohort study

Abstract Introduction Cavo tricuspid isthmus ablation (CTIA) is an effective first-line treatment for typical atrial flutter (AFL). However, many patients develop atrial fibrillation (AF) after successful CTIA. Knowledge about recurrent arrhythmia after CTIA mainly comes from small cohort studies with limited follow-up. Purpose To describe incidences of AFL re-ablation and AF-ablation after first-time CTIA in a nation-wide cohort. Method In the Danish National Ablation Registry we identified patients undergoing first-time CTIA during 2010–2016. Subsequent CTIA and AF-ablation procedures were identified until March 1st, 2018. We gathered information on patient comorbidities in the Danish National Patient Registry. Results We identified 2409 patients undergoing first-time CTIA. Median age was 66 (IQR 58–72) years, and 1952 (81%) were men. 78 (3%) had a history of AF. Acute procedural succes was achieved in 2288 (95%) patients. During mean follow-up of 4±1.7 years, 242 (10%) patients underwent CTI re-ablation and 326 (13.5%) ablation for AF. Baseline characteristics associated with CTI re-ablation included prolonged procedural time, unsuccessful first CTIA, age&lt;75 years and CHA2DS2-VASc score&lt;2. Hypertension, history of AF, age&lt;65 years and CHA2DS2-VASc score&lt;2 were associated with later AF-ablation (Table). Predictive characteristics Characteristics associated with CTI re-ablation HR 95% CI p-value Procedural time 1.003 (1.001–1.006) 0.01 Unsuccesful first CTIA procedure 3.42 (2.10–5.55) &lt;0.0001 Age &lt;75 years 1.52 (1.03–2.26) 0.04 CHA2DS-VAS2c score &lt;2 1.45 (1.11–1.90) 0.01 Characteristics associated with later AF-ablation Hypertension 1.31 (1.02–1.69) 0.04 History of AF 1.70 (1.07–2.71) 0.03 Age &lt;65 years 2.38 (1.89–3.01) &lt;0.0001 CHA2DS-VAS2c score &lt;2 1.77 (1.40–2.45) &lt;0.0001 AF: Atrial fibrillation; HR: Hazard ratio. All HR's are adjusted for age, gender, hypertension, diabetes, heart failure, iscemic heart disease, valvular heart disease, chronic obstructive lung disease, chronic kidney disease and history of AF using Cox regression analysis. Conclusion In a nation-wide cohort undergoing CTIA for AFL, 10% of patients underwent CTI re-ablation and 13.5% were ablated for AF during mean follow-up of 4±1.7 years. Probability of undergoing a second ablation procedure was higher in younger patients with less comorbidity.

Recurrent atrial flutter ablation and incidence of atrial fibrillation ablation after first-time ablation for typical atrial flutter: A nation-wide Danish cohort study

BackgroundCavo tricuspid isthmus ablation (CTIA) is considered an effective first-line treatment for typical atrial flutter (AFL). However, many patients develop atrial fibrillation (AF) after successful CTIA. Knowledge about recurrent arrhythmia after CTIA mainly comes from small cohort studies with limited follow-up. ObjectiveTo describe incidences of re-ablation for AFL and ablation for AF after first-time CTIA in a nation-wide cohort. MethodsIn the Danish National Ablation Registry we identified patients undergoing first-time CTIA during 2010–2016. Subsequent CTIA and AF-ablation procedures were identified until March 1st, 2018. We collected information on patient comorbidities in the Danish National Patient Registry. ResultsWe identified 2409 patients undergoing first-time CTIA. Median age was 66 (IQR 58–72) years, 1952 (81%) were men, and 78 (3%) patients had a history of previous ablation for AF. Acute procedural success was achieved in 2288 (95%) patients. During mean follow-up of 4.0 ± 1.7 years, 242 (10%) patients underwent CTI re-ablation and 326 (13.5%) underwent ablation for AF. Baseline characteristics associated with CTI re-ablation included prolonged procedural time, unsuccessful index CTIA, age <75 years and CHA2DS2-VASc score <2. Hypertension, history of AF-ablation, age <65 years use of a contact force sensing catheter and CHA2DS2-VASc score <2 were associated with later ablation for AF. ConclusionIn a nation-wide cohort undergoing first-time CTIA for AFL, 10% of patients underwent CTI re-ablation and 13.5% ablation for AF during mean follow-up of 4.0 ± 1.7 years. Probability of a second procedure was higher in younger patients with less comorbidities.