Successful Cavotricuspid Isthmus Ablation Research Articles

Local impedance and contact force guidance to predict successful cavotricuspid isthmus ablation with a zero-fluoroscopy approach.

A new technology capable of monitoring local impedance (LI) and contact force (CF) has recently been developed. At the same time, there is growing concern regarding catheter ablation performed under fluoroscopy guidance, due to its harmful effects for both patients and practitioners. The aim of this study was to assess the safety and effectiveness of zero-fluoroscopy cavotricuspid isthmus (CTI) ablation monitoring LI drop and CF as well as to elucidate if these parameters can predict successful radiofrequency (RF) applications in CTI ablation. We conducted a prospective observational study recruiting 50 consecutive patients who underwent CTI ablation. A zero-fluoroscopy approach guided by the combination of LI drop and CF was performed. In each RF application, CF and LI drop were monitored. A 6-month follow-up visit was scheduled to assess recurrences. A total of 767 first-pass RF applications were evaluated in 50 patients. First-pass effective RF applications were associated with greater LI drops: absolute LI drops (30.05 ± 6.23 Ω vs. 25.01 ± 5.95 Ω), p = 0.004) and relative LI drops (-23.3 ± 4.9% vs. -18.3 ± 5.6%, p = 0.0005). RF applications with a CF between 5 and 15 grams achieved a higher LI drop compared to those with a CF below 5 grams (29.4 ± 8.76 Ω vs. 24.8 ± 8.18 Ω, p < 0.0003). However, there were no significant differences in LI drop between RF applications with a CF between 5 and 15 grams and those with a CF beyond 15 grams (29.4 ± 8.76 Ω vs. 31.2 ± 9.81 Ω, p = 0.19). CF by itself, without considering LI drop, did not predict effective RF applications (12.3 ± 7.54 g vs. 11.18 ± 5.18 g, p = 0.545). Successful CTI ablation guided by a zero-fluoroscopy approach was achieved in all patients. Only one patient experienced a recurrence during the 6-month follow-up. LI drop (absolute and relative values) appears to be a good predictor of successful RF applications to achieve CTI conduction block. The optimal CF to achieve a good LI drop is between 5 and 15 g. A zero-fluoroscopy approach guided by LI and CF was feasible, effective, and safe.

Abstract 12570: Catheter Ablation Rates for Typical Atrial Flutter in Military Tactical Athletes

Introduction: Cavotricuspid isthmus (CTI)-dependent atrial flutter is known to adversely impact exercise physiology and occupational readiness in active-duty military personnel. Despite guideline recommendations supporting catheter ablation for CTI-dependent flutter, there is a paucity of literature reporting the utilization and outcomes of catheter ablation in military personnel and other tactical athletes. Aims: This study aims to characterize United States military personnel diagnosed with CTI-dependent flutter and investigate the rates of catheter ablation and personnel returning to tactical athletic occupations. Methods: Military personnel diagnosed with CTI-dependent flutter from 2016 to 2022 were analyzed. Baseline clinical characteristics and typical flutter management was reviewed. CTI-flutter diagnoses were confirmed by electrocardiogram and electrophysiology study with entrainment or activation mapping. Results: During the study dates 40 military members (mean age, 40.7±10.7 years; 98% male; mean BMI 28.3±4.2 kg/m 2 ; mean LVEF 58.3%±7.7) were diagnosed with typical flutter. 34/40 (85%) of service members diagnosed with typical flutter were retained on military status after diagnosis. Of those retained, 13/34 (38.2%) were able to complete deployments. Electrophysiology study and successful CTI ablation was performed in 27/40 (67.5%) of personnel with zero complications. 26/27 (96.3%) servicemembers who underwent CTI ablation maintained their tactical occupation whereas only 8/13 (61.2%) service members who did not receive CTI ablation were retained (p=0.009). 10/27 (37.0%) who received CTI ablation were able to subsequently deploy whereas only 3/13 (23%) who did not receive CTI ablation were able to deploy (p=0.484). Conclusions: Most military tactical athletes with CTI-dependent flutter receive safe and effective CTI ablations. CTI ablation increases tactical occupation retention rates when compared to treatment without CTI ablation. This data supports the use of CTI ablation as first-line treatment for military personnel and highlights the role of increasing ablation rates in other similar athletic populations.

Prognostic impact of cavotricuspid isthmus ablation for typical atrial flutter in patients with heart failure and reduced ejection fraction

Abstract Background The CASTLE-AF trial in 2018, showed that pulmonary vein isolation provides a survival benefit and a reduced hospitalization rate in patients with heart failure and concomitant atrial fibrillation. Typical atrial flutter (AFL) can also induce heart failure (tachymyopathy) or, if cardiomyopathy of other origin is prevalent, can further worsen it. Cavotricuspid isthmus ablation (CTI) is a simple, invasive electrophysiological procedure that can effectively treat AFL. Prognostic data on the impact of CTI in patients with heart failure and reduced ejection fraction (HFrEF) is lacking. Purpose This study focused on the analysis of the clinical impact of CTI vs. medical therapy in patients with HFrEF. Methods The present retrospective, international, multi-center study included 104 patients &amp;lt;85 years with AFL and heart failure (LVEF &amp;lt;50%). 64 patients underwent an electrophysiological study with successful CTI (ablation group), whereas 40 patients received medical therapy alone with frequency or rhythm control and guideline-compliant heart failure therapy (medical therapy group). Patients were followed up for a total of 2 years, with particular emphasis on recording the change in LVEF over time. The primary endpoints were cardiovascular mortality and hospitalization for cardiac causes. Results Patients after CTI showed a significant increase in LVEF after 1 year (with the exception of valvular cardiomyopathy). The optimization of LVEF was also reflected in the Kaplan-Meier curves, as the ablation group had a significantly lower 2-year, cardiovascular mortality (p&amp;lt;0.001). The hospitalization rate for cardiac causes in the overall cohort showed a tendency towards reduced hospitalizations (p=0.072). Elderly patients also benefited from CTI in this study. Specifically, Patients ≥70 years of age showed a significantly lower re-hospialization rate after CTI (p=0.043) as well as a significantly reduced mortality after 2 years (p=0.012). Conclusions CTI in patients with AFL and HFrEF was associated with significant optimization of LVEF and lower rates of hospitalization and mortality after 2 years. Patient age should not be a primary exclusion criterion for CTI because in this study, patients ≥70 years also benefited significantly from intervention in terms of mortality and hospitalization. Funding Acknowledgement Type of funding sources: None.

Risk of New-Onset Atrial Fibrillation Post-cavotricuspid Isthmus Ablation in Typical Atrial Flutter Without History of Atrial Fibrillation.

Aims: The aim was to describe the incidence of atrial fibrillation (AF) after cavotricuspid isthmus (CTI) ablation in patients with typical atrial flutter (AFL) without history of AF and to identify risk factors for new-onset AF after the procedure.Methods: A total of 191 patients with typical AFL undergoing successful CTI ablation were enrolled. Patients who had history of AF, structural heart disease, cardiac surgery, or ablation or who received antiarrhythmic drug after procedure were excluded. Clinical and electrophysiological data were collected.Results: There were 47 patients (24.6%) developing new AF during a follow-up of 3.3 ± 1.9 years after CTI ablation. Receiver operating characteristic (ROC) curves indicated that the cut-off values of left atrial diameter (LAD) and CHA2DS2-VASc score were 42 mm and 2, with area under the curve of 0.781 and 0.550, respectively. The multivariable Cox regression analysis revealed that obstructive sleep apnea (OSA) [hazard ratio (HR) 3.734, 95% confidence interval (CI) 1.470–9.484, P = 0.006], advanced interatrial block (aIAB) (HR 2.034, 95% CI 1.017–4.067, P = 0.045), LAD > 42 mm (HR 2.710, 95% CI 1.478–4.969, P = 0.001), and CHA2DS2-VASc score > 2 (HR 2.123, 95% CI 1.118–4.034, P = 0.021) were independent risk factors of new-onset AF.Conclusion: A combination of OSA, aIAB, LAD > 42 mm, and CHA2DS2-VASc > 2 was a strongly high risk for new-onset AF after ablation for typical AFL, and it had significance in postablation management in clinical practice.

Preventing atrial fibrillation by combined right isthmus ablation and cryoballoon pulmonary vein isolation in patients with typical atrial flutter: PAF-CRIOBLAF study.

BackgroundAlthough less common, typical atrial flutter shares similar pathophysiological roots with atrial fibrillation. Following successful cavo‐tricuspid isthmus ablation using radiofrequency, many patients, however, develop atrial fibrillation in the mid‐to‐long‐term. This study sought to assess whether pulmonary vein isolation conducted at the same time as cavo‐tricuspid isthmus ablation would significantly modify the atrial fibrillation burden upon follow‐up in patients suffering from typical atrial flutter.MethodsThis was a multicenter randomized controlled study involving typical atrial flutter patients with history of non‐predominant atrial fibrillation (1 atrial fibrillation episode only, in 67% of population) who were scheduled for cavo‐tricuspid isthmus radiofrequency ablation. Patients were randomly assigned to either undergo cavo‐tricuspid isthmus ablation alone or cavo‐tricuspid isthmus plus pulmonary vein isolation (CTI+). Pulmonary vein isolation was performed using cryoballoon technology. An outpatient consultation with ECG and 1‐week Holter monitoring was performed at 3, 6 months, 1 year, and 2 years postprocedure. The primary endpoint was atrial fibrillation recurrences lasting more than 30 s at 2 years postablation.ResultsOf the patients enrolled, 36 were included in each group. At 2‐year follow‐up, the atrial fibrillation recurrence rate was significantly higher in the CTI vs CTI+group (25/36, 69% vs. 12/36, 33% respectively; P < .001), with similar typical atrial flutter recurrence rates. There were no differences in undesirable events, except for transient phrenic nerve palsy reported from three CTI+patients (8.3%).ConclusionPulmonary vein isolation using cryoballoon technology was proven to significantly reduce the atrial fibrillation incidence at 2 years postcavo‐tricuspid isthmus ablation.

B-PO04-098 EVALUATION OF LESION SIZE INDEX (LSI) PERFORMANCE TO GUIDE CAVOTRICUSPID ISTHMUS ABLATION

Lesion size index (LSI) integrates contact force, radiofrequency current and lesion duration to provide real-time lesion formation data. To describe LSI performance and outcomes in patients undergoing cavotricuspid-isthmus (CTI) ablation at the Hospital of the University of Pennsylvania. All patients undergoing CTI-only ablation using TactiCath ablation catheter and EnSite Precision mapping were retrospectively reviewed for clinical characteristics and individual lesion data including LSI, force-time integral (FTI, gs), mean contact force (CF, g), lesion duration (s) and number of lesions. We report the 1 year procedural outcome. Between April ‘18 and December ‘19, 21 patients underwent CTI-only ablation with 100% acute procedural success (bidirectional block), no procedural complications, and no clinical recurrence after 1 year. One patient (4.8%) required redo ablation after 17 months (no clinical recurrence, but chronic reconnection was documented during atrial fibrillation ablation). Clinical characteristics (median, interquartile range [IQR]) were as follows: age 65 years (58-68), EF 55% (38-65%), CHADS-Vasc score 2 (1-4), and 19/21 were men (90.5%). A total of 605 lesion points were analyzed (median 24 lesions per patient, IQR 15-32). Lesion parameters (average, standard deviation) were as follows: LSI 5.2±0.8, FTI 238±135gs, CF 15.5±7.7g, lesion duration 16.9±10.4s. LSI best correlated with mean CF (r = 0.68) followed by FTI (r = 0.39); there was no correlation with lesion duration (r = -0.07). LSI can safely guide successful CTI ablation with mean of LSI 5.2 correlating with mean CF of 15.5g and mean FTI of 238gs.

Implantable loop recorder for augmenting detection of new-onset atrial fibrillation after typical atrial flutter ablation.

BackgroundPatients with typical atrial flutter (AFL) undergoing successful cavotricuspid isthmus ablation remain at risk for future development of new-onset atrial fibrillation (AF). Conventional monitoring (CM) techniques have shown AF incidence rates of 18%–50% in these patients.ObjectivesTo evaluate whether continuous monitoring using implantable loop recorders (ILRs) would enhance AF detection in this patient population.MethodsVeteran patients undergoing AFL ablation between 2002 and 2019 who completed at least 6 months of follow-up after the ablation procedure were included. We compared new-onset AF detection between those who underwent CM and those who received ILRs immediately following AFL ablation.ResultsA total of 217 patients (age: 66 ± 9 years; all male) participated. CM was used in 172 (79%) and ILR in 45 (21%) patients. Median follow-up duration after ablation was 4.1 years. Seventy-nine patients (36%) developed new-onset AF, which was detected by CM in 51 and ILR in 28 (30% vs 62%, respectively, P < .001). AF detection occurred at 7.7 months (IQR: 4.7–17.5) after AFL ablation in the ILR group vs 41 months (IQR: 23–72) in the CM group (P < .001). Eleven patients (5%) experienced cerebrovascular events (all in the CM group) and only 4 of these patients (36%) were on long-term anticoagulation.ConclusionPatients undergoing AFL ablation remain at an increased risk of developing new-onset AF, which is detected sooner and more frequently by ILR than by CM. Improving AF detection may allow optimization of rhythm management strategies and anticoagulation in this patient population.

Abstract 14375: Does Race Provide Protection From New Onset Atrial Fibrillation After Typical Flutter Ablation in Male Veteran Patients?

Introduction: Patients undergoing typical atrial flutter (AFL) ablation remain at risk of developing atrial fibrillation (AF). However, it is unknown whether common risk factors associated with AF occurrence, particularly race, bear out in this population. Hypothesis: We sought to compare the occurrence of new AF in male veteran African-American (AA) and Caucasian (Cau) patients with AFL following successful cavo-tricuspid isthmus ablation. Methods: A retrospective review of patients undergoing AFL ablation between 2002 and 2019 was performed. Patients with prior history of AF were excluded. Records were reviewed and demographics, comorbidities and post-ablation outcomes including new AF and stroke were recorded. The overall incidence of AF and cases per 1000 person-years (CPTPY) were determined. Results: The study cohort comprised 217 patients (age: 66±9.3 years, AA: 97 [45%], Cau:108 [50%]; see Table) with a mean follow-up of 55±42 months after AFL ablation. New AF was detected in 30 (31%) AA and 45 (42%) Cau patients (p=0.21 by Log Rank test). Overall incidence of AF was 78 CPTPY (67 and 91 CPTPY cases in AA and Cau patients, respectively). Time to occurrence of AF was earlier in Cau than AA patients (p=&lt;0.001). New stroke events occurred in 9 (4.4%) patients (4 AA, 5 Cau; p=0.86). Conclusions: Male AA and Cau patients have similar significant risks for developing AF and experiencing stroke after AFL ablation.

CHA2DS2-VASc Score as a Predictor of New-Onset Atrial Fibrillation After Catheter Ablation of Typical Atrial Flutter.

PurposeCavotricuspid isthmus (CTI) ablation is an effective procedure for typical atrial flutter (AFL), but patients remain at an elevated risk for developing new atrial fibrillation (AF). Currently, there are limited data on the utility of CHA2DS2-VASc score to predict new-onset AF after typical AFL ablation. In this study, we assessed whether the CHA2DS2-VASc score is a useful predictor of new-onset AF after CTI ablation in typical AFL patients without a prior history of AF.MethodsThis was a retrospective study of 103 typical AFL patients with no prior history of AF, who underwent successful CTI ablation. The endpoint was occurrence of new-onset AF during follow-up.ResultsDuring a mean follow-up period of 24.6 ± 16.9 months, at least one episode of AF occurred in 33 (32%) patients. Multivariate Cox regression analysis revealed that CHA2DS2-VASc score (hazard ratio = 1.736; 95% confidence interval = 1.370–2.201; P < 0.001) was significantly associated with postablation new-onset AF (area under the curve = 0.797). A cutoff value of three stratified these patients into two groups with different incidences of postablation new-onset AF (67.9 vs. 18.7%, P < 0.001).ConclusionThe CHA2DS2-VASc score is a useful tool for the prediction of new-onset AF after ablation of typical AFL. Patients with CHA2DS2-VASc score ≥3 are more likely to develop new-onset AF and should be monitored more closely.

A Retrospective Study of Atrial Fibrillation Following Cavotricuspid Isthmus Ablation for Atrial Flutter.

BackgroundCatheter radiofrequency ablation for typical atrial flutter is considered to be safe and effective. However, atrial fibrillation (AF) following cavotricuspid isthmus ablation for atrial flutter has been reported in patients without a previous history of AF, which has implications for the decision to use oral anticoagulation. This retrospective study at a single center aimed to evaluate the occurrence of AF in patients after successful cavotricuspid isthmus ablation of typical atrial flutter and to determine the incidence and associations with AF during follow-up.Material/MethodsBetween January 2011 and July 2017, of 110 consecutive patients who underwent cavotricuspid isthmus ablation for typical atrial flutter, 67 patients had no previous history of AF, of which 40 patients underwent follow-up. The 40 patients included in this retrospective clinical study included 34 men and 6 women, with a mean age of 67±10 years.ResultsForty patients underwent post-ablation follow-up for 46±23 months, and 12 patients (30%) developed AF; six patients (15%) experienced recurrent of atrial flutter. More than half of the patients with post-ablation AF were asymptomatic with a European Heart Rhythm Association (EHRA) score of 1, and univariate analysis showed the absence of variables associated with the prevalence of AF.ConclusionsFollowing cavotricuspid isthmus ablation for atrial flutter, recurrence of atrial flutter was found in 15% of cases, and asymptomatic AF occurred in 30%. These findings have implications for the use of post-ablation oral anticoagulation treatment, which is often discontinued following ablation therapy and before patient follow-up.

P3857Is it safe to withdraw oral anticoagulation after successful cavotricuspid isthmus ablation regardless of the CHA2DS2-VASc?

P3857Is it safe to withdraw oral anticoagulation after successful cavotricuspid isthmus ablation regardless of the CHA2DS2-VASc?

Focal intra-cavotricuspid isthmus atrial tachycardias occurring after typical atrial flutter ablation: incidence and electrocardiographic and electrophysiological characteristics.

Focal atrial tachycardias (ATs) from the septal cavotricuspid isthmus (CTI) occurring after successful CTI ablation can mimic typical atrial flutter (tAFL). This study investigated the incidence, and electrocardiographic and electrophysiological characteristics of these ATs. Among 1082 consecutive patients undergoing successful CTI ablation without any congenital heart diseases, 7 were diagnosed with focal ATs originating from the septal CTI that occurred a median of 74days after the CTI ablation. The electrocardiographic characteristics of the ATs were similar to those of the tAFLs. The AT's cycle length was never shorter than and often similar to that of tAFLs. The activation patterns along the tricuspid annulus during the ATs were the same as those of tAFLs in 4 patients with foci adjacent to the CTI line, and centrifugal from foci around the coronary sinus (CS) ostium in 3. Entrainment pacing from the lateral CTI during the ATs revealed a manifest fusion and long post-pacing interval. Entrainment pacing from the lateral CTI during the ATs revealed that the atrial electrograms recorded from the CS and high-lateral right atrium were orthodromically captured, while that from the proximal CS revealed that the atrial electrograms recorded from the CS and lateral right atrium were antidromically captured without manifest fusion. Focal intra-CTI ATs with a microreentrant mechanism very rarely occurred after successful CTI ablation. The electrocardiographic and electrophysiological characteristics of these ATs were similar to those of tAFLs. Overdrive pacing from the lateral CTI and proximal CS was helpful for distinguishing these ATs from recurrent tAFLs.

Incidence of new-onset atrial fibrillation after cavotricuspid isthmus ablation for atrial flutter.

In patients with cavotricuspid isthmus (CTI) ablation for atrial flutter (AFL), the decision to hold oral anticoagulation (OAC) often becomes an issue. The purpose of this study was to describe the incidence of the development of atrial fibrillation (AF) after CTI ablation in patients with documented AFL with and without a previous history of AF and to identify risk predictors for the occurrence of AF after CTI. We included 364 consecutive patients undergoing successful CTI ablation. Thereof, 230 patients (170 male; age 66 ± 11 years) had AFL only (AFL group) and 134 patients (94 male; age 65 ± 11 years) had AFL and previously documented AF (AFL and AF group). Over a mean follow-up of 22 ± 20 months, 163 (71%) patients in the AFL group and 67 (50%) patients in the AFL and AF groups had no documentation of a recurrent atrial arrhythmia (P < 0.001). AF developed in 51 patients (22%) in the AFL group and in 57 (43%) patients in the AFL and AF groups (P < 0.001). In patients without history of AF, left atrial diameter was the only predictor of development of AF (HR 1.058 [95%CI 1.011-1.108], P = 0.016). Multivariate analysis of the total population identified history of AF (HR 1.918 [95%CI 1.301-2.830], P = 0.001) and BMI as predictors for AF development (HR 1.052 [95%CI 1.012-1.093], P = 0.011). Our results indicate that new-onset AF develops in a significant proportion of patients undergoing CTI for AFL. One should therefore be careful to withhold OAC. Furthermore, pulmonary vein isolation should be considered in conjunction with CTI, particularly in patients with previously documented AF.

Cardiac and neurogenic syncope and atrial flutter misdiagnosed as ventricular tachycardia in a patient after myocardial infarction

A 61-year-old male presented with a history of transient ischaemic cerebral episode (ten years earlier), previous myocardial infarction (MI) treated with percutaneous coronary intervention of the left circumflex artery, and deployment of a drug-eluting stent (four years earlier). Initially, he was admitted to hospital because of retrosternal pain and recurrent syncope that followed a wide QRS complex tachycardia (WCT). The arrhythmia was originally diagnosed as ventricular tachycardia (VT) and reverted to sinus rhythm (SR) using a direct current cardioversion (DCCV) followed by an intravenous amiodarone infusion. Despite the treatment, the same arrhythmia reoccurred and was accompanied by two episodes of syncope and retrosternal pain. Therefore, he was referred to cardiology department as recurrent VT secondary to acute coronary syndrome (troponin I 0.25 ng/mL) was suspected. On admission, he reported fatigue, dizziness, and preor syncope episodes that started two days earlier. The electrocardiogram (ECG) revealed WCT (HR = 210 bpm) of left bundle branch block (LBBB) morphology (QRS = 140 ms) (Fig. 1A). Intravenous amiodarone bolus plus a gentle carotid sinus massage (CSM) produced significant vasovagal reaction revealing atrial flutter (AFl) wave (Fig. 1B). Ultimately, DCCV to SR was performed (100 J), but AFl recurred shortly. Echocardiography and coronary angiography documented no abnormalities. The patient was qualified to cavotricuspid isthmus (CTI) radiofrequency ablation. Anticlockwise AFl (CL = 217 ms) with 2:1 atrioventricular conduction was confirmed at invasive procedure. During the manipulation with the coronary sinus catheter introduced via the external jugular vein, accidental tapping of the right carotid sinus region produced a 14-second vasovagal syncope deteriorating to ventricular fibrillation (Fig. 1C). Immediate defibrillation (200 J) restored SR and a success ful CTI ablation was completed. No VT was induced with a programmed ventricular stimulation. The patient was sent for thoracic angio-magnetic resonance imaging. As well as fibrotic tissue, it revealed blood flow limitation at the right carotid sinus level. Ultimately, a dual-chamber pacemaker was implanted. No recurrent syncope or arrhythmias were observed during the subsequent 12 months. Syncope can precede cardiac arrest, especially in patients with organic heart disease. A male with previous MI and fast LBBB-WCT resulting in syncope must be suspected of VT requiring eventual implantation of a cardioverter-defibrillator. However, if excluded, it needs further differential diagnosis of WTC. Valsalva manoeuvre and CSM may be helpful in aberrated atrial arrhythmias that can be treated with radiofrequency ablation. In this patient, WCT initially misdiagnosed as VT could contribute to cardiac syncope. Moreover, in our case, the response to mild CSM was enormous, suggesting substantial carotid sinus hypersensitivity leading to neurocardiogenic syncope. The disease is also treatable, and symptoms may be resolved with implantation of a pacemaker. In the presented case the ECG diagnosis of WCT may be quite error-prone.

New-onset atrial fibrillation after cavotricuspid isthmus ablation: identification of advanced interatrial block is key.

A significant proportion of patients develop atrial fibrillation (AF) following cavotricuspid isthmus (CTI) ablation for typical atrial flutter (AFl). The objective of this study was to assess whether the presence of advanced interatrial block (aIAB) was associated with an elevated risk of AF after CTI ablation in patients with typical AFl and no prior history of AF. This study included patients with typical AFl and no prior history of AF that were referred for CTI ablation. Patients were excluded when they had received repeat ablations or did not demonstrate a bidirectional block. In all patients, a post-ablation electrocardiogram (ECG) in sinus rhythm was evaluated for the presence of aIAB, defined as a P-wave duration ≥120 ms and biphasic morphology in the inferior leads. New-onset AF was identified from 12-lead ECGs, Holter monitoring, and device interrogations. The cohort comprised 187 patients (age 67 ± 10.7 years; ejection fraction 55.8 ± 11.2%). Advanced interatrial block was detected in 18.2% of patients, and left atrium was larger in patients with aIAB compared with those without aIAB (46.2 ± 5.9 vs. 43.1 ± 6.0 mm; P = 0.01). Over a median follow-up of 24.2 months, 67 patients (35.8%) developed new-onset AF. The incidence of new-onset AF was greater in patients with aIAB compared with those without aIAB (64.7 vs. 29.4%; P < 0.001). After a comprehensive multivariate analysis, aIAB emerged as the strongest predictor of new-onset AF [odds ratio (OR) 4.2, 95% confidence interval (CI): 1.9-9.3; P < 0.001]. Advanced interatrial block is a key predictor for high risk of new-onset AF after a successful CTI ablation in patients with typical AFl.

Incremental pacing maneuver for atrial flutter recurrence reduction after ablation: Vallès: Yield of incremental pacing after flutter ablation

BackgroundA <20ms increase in the interval between cavo-tricuspid isthmus (CTI) double potentials during incremental pacing (IP) is a highly specific marker differentiating functional from complete CTI block during typical flutter (AFL) ablation. Long-term effects of IP remain unclear. We aimed to assess the impact of IP in reducing AFL recurrences after CTI ablation. MethodsOne hundred and thirty-four patients (age 67±13years, 78% males) undergoing successful CTI ablation were included and divided into 2 groups: Group 1 (n=68), in which ablation was performed before the IP maneuver was incorporated, with CTI block confirmed by at least 1 non-local and 1 local electrogram-based previously established criteria; and Group 2 (n=66), in which IP maneuver was used to confirm complete CTI block. ResultsNo intergroup differences were noted in baseline characteristics, ablation settings and fluoroscopy/radiofrequency times. Long-term AFL recurrences were observed in 14 out of 134 patients (10.4%), and were more common in Group 1 (19%, vs 1.5% among Group 2 patients, p<0,001). Despite a longer follow-up period among the former group (1603±734 vs. 964±289days, respectively), the adjusted AFL recurrence rate was still higher among Group 1 patients (4.3%/year vs. 0.6%/year, p<0,001). Cox-regression analysis confirmed inclusion in Group 1 as the only predictor of AFL recurrences (HR=8.2, CI 1.04–64.7, p=0.046). ConclusionsThe addition of the IP maneuver for the diagnosis of complete CTI block reduces AFL long-term recurrences after ablation.

Pace capture in the line of block predicts recurrence of typical atrial flutter after successful cavotricuspid isthmus ablation

Pace capture in the line of block predicts recurrence of typical atrial flutter after successful cavotricuspid isthmus ablation

069 CASE SERIES OF ATRIAL FLUTTER WITH 1:1 CONDUCTION: A COMPARATIVE ANALYSIS AMONG GROUPS OF PATIENTS SUFFERING SPONTANEOUS VERSUS DRUG INDUCED 1:1 CONDUCTING ATRIAL FLUTTER:

Background Atrial flutter with 1:1 (AFL 1:1) conduction may be spontaneous or secondary to anti-arrhythmic drug (AAD) use. This group of patients are not well characterised. We aimed to compare various characteristics between patients suffering 9spontaneous9 AFL 1:1 (the development of 1:1 Atrioventricular conducting Atrial Flutter in the absence of concomitant AAD use) and 9Drug-induced9 AFL 1:1. Methods This is a retrospective study of patients referred to our institution over an 8 year period. Sixty-eight patients had confirmed and documented atrial flutter with 1:1 conduction. Results Baseline clinical characteristics and differences between the study populations are summarised in Table. Patients with spontaneous AFL 1:1 had a significantly higher flutter rate and were less likely to have concomitant AF. Drug-induced AFL 1:1 was mainly secondary to Class 1 AAD9s despite the use of AV blocking agents in a third of these patients. Sixty-three patients underwent a successful cavotricuspid isthmus ablation with no recurrence. Conclusions We have reported the largest series of patients with atrial flutter and 1:1 conduction. Patients suffering spontaneous AFL 1:1 had a significantly faster flutter rate compared to the drug-induced population.

Evaluation of factors affecting persistence of atrial fibrillation in patients with concomitant atrial flutter treated with percutaneous radiofrequency current ablation of the right atrial cavotricuspid isthmus

Atrial fibrillation (AF) and atrial flutter (AFL) often coexist. In some patients, AF remission is seen after successful percutaneous radiofrequency current ablation of the cavotricuspid isthmus (CTI). To evaluate factors affecting AF remission in patients with typical AFL and concomitant AF who underwent CTI ablation. The study included consecutive 69 patients with typical AFL and concomitant clinically documented AF who underwent successful CTI ablation in 2003-2010. Based on the follow-up data from medical records and telephone interviews, the patients were divided into two groups: with persistent AF (group A) and with remission of AF (group B). This distinction was based on arrhythmia symptoms reported by the patient, such as palpitation or irregular heartbeat, and confirmed electrocardiographically (12-lead ECG or Holter monitoring). Group A included 47 patients, and group B included 22 patients. The two groups did not differ significantly in regard to the New York Heart Association (NYHA) functional class and concomitant diseases including diabetes, ischaemic heart disease, previous myocardial infarction and arterial hypertension. The two groups also did not differ by echocardiographically determined mean left ventricular ejection fraction (LVEF) and left atrial dimension (43.5 ± 9.27 vs. 39.27 ± 5.76, p = 0.075). Multivariate logistic regression did not identify any independent risk factors of AF persistence after CTI ablation. Univariate logistic regression also did not show arterial hypertension, type 2 diabetes, previous myocardial infarction, LVEF, left ventricular dimension or age to affect AF persistence after successful ablation. Based on the results of our study, we were unable to identify factors determining remission of AF coexisting with AFL in patients after percutaneous CTI ablation. These findings may indicate the need for complex ablation procedure (involving both CTI and pulmonary venous ostia ablation) in patients in whom these two arrhythmias coexist.

Prospective Observations in the Clinical and Electrophysiological Characteristics of Intra‐Isthmus Reentry

Intra-isthmus reentry (IIR) is a circuit within the cavotricuspid isthmus (CTI). The purpose of this study is to prospectively define the electrogram and surface ECG characteristics of IIR, and its clinical implications. Fourteen patients underwent electrophysiological studies and were found to have IIR. Detailed electrogram mapping of the CTI was available in all, electroanatomic mapping (EAM) in 8 of 14 (57%) patients. In all, entrainment mapping during tachycardia proved reentry, and showed that the anteroinferior CTI was out of the circuit and the septal CTI was in the circuit in 12 of 14 patients, whereas in 2, the circuit was confined within the mid and/or anteroinferior CTI. Fractionated potentials (FPs) spanning 34-71% of the tachycardia cycle length were recorded within the CTI in all, and double potentials were inscribed in 10 of 14 (71%). Analysis of the tricuspid annulus electrograms showed spontaneous shifts from a counterclockwise (CCW) to clockwise or fusion patterns. Surface ECGs showed either typical CCW pattern (12 patients) or atypical patterns (3 patients). The EAMs showed a focal pattern in 3, a CCW pattern in 5. The successful ablation site always occurred at the area with maximal FP duration. Over the same period, 33 of 384 (9%) patients who underwent ablation for CTI-dependent flutter had prior successful CTI ablation, 7 of 33 (21%) were found to have IIR during the redo procedure. (1) Electrogram and ECG patterns of IIR frequently show atypical flutter. (2) IIR was successfully ablated in an area of the CTI associated with maximal duration of FPs. (3) IIR is a significant cause of "recurrent flutter" in patients with prior CTI ablation.