Atrial Flutter Ablation Research Articles

Ablation of atrial flutter in a patient after Fontan procedure: a case report of challenging access to the common atrium

Abstract Background In patients with a total cavopulmonary connection in Fontan circulation, the access to the common atrium (CA) during a catheter ablation can be challenging, even in the presence of fenestration in an intra-atrial lateral tunnel (IALT). In our department, the fenestration is typically marked with metal clips (MCs). To the best of our knowledge, there is no previous report of balloonoplasty of clipped fenestration. Case summary A 19-year-old male with hypoplastic left heart syndrome (HLHS) was scheduled for catheter ablation of recurrent atrial tachycardia. He was diagnosed with HLHS prenatally and underwent a stepwise surgical palliation. Fontan circulation was completed with the creation of a fenestrated IALT. The fenestration was marked by four MCs. During the ablation procedure, the passage of the steerable sheath with mapping catheter to the CA was prevented by a small fenestration size and rigidness of the edges of the fenestration caused by the MCs. Multiple attempts to dilate the fenestration using a peripheric angioplasty balloon failed. Only angioplasty with the ‘balloon-against-dilator’ technique was finally successful. Activation map showed a counterclockwise atrial flutter in the CA; successful ablation was performed. Discussion We present a case of challenging access to the CA through a clipped fenestration in a polytetrafluoroethylene baffle for atrial tachycardia ablation. Even though a tunnel fenestration in Fontan patients facilitates access to the CA, the passage of a steerable introducer with a mapping catheter may be challenging due to diameter mismatch and the rigidity of its edges caused by MCs. The balloon-against-dilator technique might be helpful when conventional balloon angioplasty fails.

Analysis of the endocardial stage of treatment of tachyarhythmias after open interventions for atrial fibrillation. Experience of one center

AIM: To study EFI parameters and features of recurrent atrial tachyarrhythmias in patients who underwent surgical correction of AF.
 MATERIALS AND METHODS: from January 2013 to December 2021, 447 combined interventions were performed to eliminate AF using the labyrinth-3 and left atrial labyrinth techniques with correction of CHD (congenital heart disease) and/or coronary artery disease.
 Rhythm disturbances were detected in 57 (12.7%) patients at various follow-up periods. Endovascular interventions were performed in 39 patients. The average follow-up period after the endocardial stage was 34.37 (standard deviation 24.32) months. The median age of patients was 64 (58–67) years, 21 (54%) were men. The patients were divided into 2 groups: group 1 — after the classic biatrial (BA) labyrinth-3 — 23 (59%) patients, group 2 — after the left-atrial variant (LA) labyrinth-3 — 16 (41%) patients.
 At the endocardial stage, electrophysiological studies (EFI) were performed to clarify the mechanism of arrhythmia, and ablation eliminated tachyarrhythmia. EFI protocol: revision of the pulmonary veins, determination of the isolation of the posterior wall of the LA assessment of atrial arrhythmia, elimination of arrhythmia, control induction of arrhythmia after ablation. After repeated intervention, patients were observed in the operating clinic every 3 months.
 RESULTS: After the endocardial stage, a regular rhythm was determined in 19 (82.6%) patients of the BA group, 13 (92.9%) patients of the LA group (p = 0.914). Relapses in the form of AF were noted in 5 patients (4 — group 1 and 1 — group 2) group (p = 0.306) All relapses of tachyarrhythmia with an irregular cycle (AF) were detected in patients with AF before the endovascular stage In both groups, there were cases of restoration of conduction in the pulmonary veins — 10 (43.5%) patients after BA ablation and 1 (5.3%) patient after LA ablation. There are no recurrences of atrial arrhythmia after ablation of atrial flutter (arrhythmia with a stable cycle).
 CONCLUSION: The endocardial stage is highly effective and demonstrates subsequent freedom from atrial arrhythmia in patients who have tachycardia with a regular cycle after both methods of surgical ablation of AF. Recurrent tachyarrhythmia in the form of AF (irregular cycle) is associated with a low probability of maintaining a regular atrial rhythm after a repeated endocardial procedure, due to the presence of structural and electrophysiological changes in the atrial myocardium.

Catheter ablation of supraventricular tachycardia and atrial flutter with no or minimal use of fluoroscopy: the initial experience of a single Bulgarian center

Introduction: Catheter ablation (CA) is an established therapy for most arrhythmias. Non-fl uoroscopic three-dimensional (3D) electroanatomic mapping systems allow ablation of supraventricular tachycardia (SVT) and atrial fl utter (AFL) with zero or near-zero fl uoroscopy (ZF/NZF). The current study aims to report our initial experience with ZF/NZF in SVT or AFL CA. Material and methods: We conducted a single-center prospective registry enrolling consecutive patients referred for CA of SVT or AFL. ZF/NZF CA was attempted in all patients using a commercially available 3D mapping system. Fluoroscopy use was allowed at any point of the procedure. Procedural characteristics and long-term outcome were analyzed. The learning curve effect was also studied. Results: Sixty-three patients (age 53.5 ± 14.1, 57% males) with SVT or AFL were enrolled. According to arrhythmia type typical AVNRT was diagnosed in 36 (57.1%) cases, right atrial fl utter in 25 (39.7%) cases, left-sided accessory pathway in 1 (1.6%) and focal right atrial tachycardia in 1 (1.6%) case. Three patients (4.8%) had two arrhythmia substrates. The procedure was performed with ZF in 49/63 cases (77.8%), while NZF was necessary in 14 (22.2%) patients with a fl uoroscopy time of 220 ± 169 sec and a dose-area product of 7556 ± 5886 mGy*cm2. Median procedural time was 88 (IQR 25-75 percentile 71.5-116) min with 22 (IQR 25-75 percentile 16-31) min of mapping time. Acute procedural success was accomplished in all patients with no periprocedural complications. Over a follow-up of 12 ± 3 months, all patients remained arrhythmia-free. There was a learning curve effect with a signifi cant reduction of procedural time (P = 0.025) and a signifi cant difference (P = 0.019) in the rate of fl uoroscopy use among different periods of the study duration. Conclusion: ZF/NZF CA of SVT and AFL is associated with high effi cacy and safety. Entirely fl uoroless CA can be performed in the vast majority of patients. It is a feasible approach associated with a detectable learning curve effect. 

Cavotricuspid Isthmus-Dependent Atrial Flutter. Beyond Simple Linear Ablation.

The demonstration of a peritricuspid circular movement with a zone of slow conduction in the cavotricuspid isthmus, together with the high efficacy of linear ablation and widely accepted acute endpoints, has established typical flutter as a disease with a well-defined physiopathology and treatment. However, certain aspects regarding its deeper physiopathology, ablation targets, and methods for verifying the results remain to be clarified. While current research efforts have primarily been focused on the advancement of effective ablation techniques, it is crucial to continue exploring the intricate electrophysiological, ultrastructural, and pharmacological pathways that underlie the development of atrial flutter. This ongoing investigation is essential for the development of targeted preventive strategies that can act upon the specific mechanisms responsible for the initiation and maintenance of this arrhythmia. In this work, we will discuss less ascertained aspects alongside the most widely recognized general data, as well as the most recent or less commonly used contributions regarding the electrophysiological evaluation and ablation of typical atrial flutter. Regarding electrophysiological characteristics, one of the most intriguing findings is the presence of low voltage zones in some of these patients together with the presence of a functional, unidirectional line of block between the two vena cava. It is theorized that episodes of paroxysmal atrial fibrillation can trigger this line of block, which may then allow the onset of stable atrial flutter. Without this, the patient will either remain in atrial fibrillation or return to sinus rhythm. Another of the most important pending tasks is identifying patients at risk of developing post-ablation atrial fibrillation. Discriminating between individuals who will experience a complete arrhythmia cure and those who will develop atrial fibrillation after flutter ablation, remains essential given the important prognostic and therapeutic implications. From the initial X-ray guided linear cavotricuspid ablation, several alternatives have arisen in the last decade: electrophysiological criteria-directed point applications based on entrainment mapping, applications directed by maximum voltage criteria or by wavefront speed and maximum voltage criteria (omnipolar mapping). Electro-anatomical navigation systems offer substantial support in all three strategies. Finally, the electrophysiological techniques to confirm the success of the procedure are reviewed.

Identification of cavotricuspid isthmus voltage patterns in typical atrial flutter ablation.

Electroanatomical mapping is an essential tool in the ablation of typical AFL. To identify the existence of voltage patterns in the CTI voltage maps and their relevance for typical AFL ablation. A voltage map of the CTI was made prior to ablation, identifying the areas of maximum voltage and their location along the CTI, allowing classification into patterns according to their distribution. A stepwise ablation approach targeting the areas of maximum voltage was conducted. The ablation characteristics were compared based on the pattern obtained. Two voltage patterns were identified, with differences in ablation time to bidirectional CTI block. No complications occurred. Voltage mapping identifies patterns in the CTI with implications for typical AFL ablation.

Kiosk 11R-TC-06 - Mr-compatible 12-lead ECG Recording During Atrial Flutter Ablation Procedure in the Interventional Cardiac Magnetic Resonance (iCMR) Suite: Exploring the Magnetohydrodynamic (MHD) Effect

Kiosk 11R-TC-06 - Mr-compatible 12-lead ECG Recording During Atrial Flutter Ablation Procedure in the Interventional Cardiac Magnetic Resonance (iCMR) Suite: Exploring the Magnetohydrodynamic (MHD) Effect

Tissue characterization of acute lesions during cardiac magnetic resonance-guided ablation of cavo-tricuspid isthmus-dependent atrial flutter: a feasibility study.

To characterize acute lesions during cardiac magnetic resonance (CMR)-guided radiofrequency (RF) ablation of cavo-tricuspid isthmus (CTI)-dependent atrial flutter by combining T2-weighted imaging (T2WI), T1 mapping, first-pass perfusion, and late gadolinium enhancement (LGE) imaging. CMR-guided catheter ablation offers a unique opportunity to investigate acute ablation lesions. Until present, studies only used T2WI and LGE CMR to assess acute lesions. Fifteen patients with CTI-dependent atrial flutter scheduled for CMR-guided RF ablation were prospectively enrolled. Directly after achieving bidirectional block of the CTI line, CMR imaging was performed using: T2WI (n = 15), T1 mapping (n = 10), first-pass perfusion (n = 12), and LGE (n = 12) imaging. In case of acute reconnection, additional RF ablation was performed. In all patients, T2WI demonstrated oedema in the ablation region. Right atrial T1 mapping was feasible and could be analysed with a high inter-observer agreement (r = 0.931, ICC 0.921). The increase in T1 values post-ablation was significantly lower in regions showing acute reconnection compared with regions without reconnection [37 ± 90 ms vs. 115 ± 69 ms (P = 0.014), and 3.9 ± 9.0% vs. 11.1 ± 6.8% (P = 0.022)]. Perfusion defects were present in 12/12 patients. The LGE images demonstrated hyper-enhancement with a central area of hypo-enhancement in 12/12 patients. Tissue characterization of acute lesions during CMR-guided CTI-dependent atrial flutter ablation demonstrates oedema, perfusion defects, and necrosis with a core of microvascular damage. Right atrial T1 mapping is feasible, and may identify regions of acute reconnection that require additional RF ablation.

Acute cardiac tamponade during atrial flutter ablation: improved hemodynamics after positive pressure ventilation: a case report

IntroductionAcute cardiac tamponade is a rare event during any type of interventional or surgical procedure. It can occur during electrophysiology procedures due to radiofrequency ablation, lead or catheter manipulation, transseptal puncture, laser lead extractions, or left atrial appendage occlusion device positioning. Cardiac tamponade is difficult to study in a prospective manner, and case reports and case series are important contributions to understanding the best options for patient care.Case summaryAn 87-year-old Caucasian male patient breathing spontaneously developed acute tamponade during an atrial flutter ablation. Pericardial drain insertion was difficult, and hypotension failed to respond to epinephrine boluses. The patient became hypoxemic and hypercarbic, requiring intubation. Unexpectedly, the blood pressure markedly increased postintubation and remained in a normal range until the pericardium was drained.ConclusionSpontaneous ventilation is considered important to maintain venous return to the right heart during cardiac tamponade. However, spontaneous ventilation reduces venous return to the left heart and worsens the paradoxical pulse in tamponade. Intravenous vasopressors are thought to be ineffective during cardiac tamponade. Our patient maintained pulmonary blood flow as indicated by end-tidal carbon dioxide measurements but had no measurable systemic blood pressure during spontaneous ventilation. Our case demonstrates that tracheal intubation and positive pressure ventilation can transiently improve left heart venous return, systemic perfusion, and drug delivery to the systemic circulation.

Severity of Left Ventricular Dysfunction in Patients With Tachycardia-Induced Cardiomyopathy: Impacts on Remodeling After Atrial Flutter Ablation

Tachycardia-induced cardiomyopathy is defined as a reversible left ventricular (LV) systolic dysfunction (SeD) resulting from a sustained fast heart rate. LV remodeling in patients with severe LV dysfunction at diagnosis remains poorly understood. In this retrospective cohort study, we described LV remodeling in 50 patients who underwent atrial flutter ablation. These patients were divided into severe LV SeD (LV ejection fraction [EF] ≤30%) and LV nonsevere SeD (LVEF 31% to 50%) at baseline. All continuous variables are expressed as median and interquartile range. LVEF was 18% (13 to 25) and 38% (34 to 41) in the SeD (n=29) and LV nonsevere SeD (n=21) groups, respectively. At baseline, patients with SeD had higher LV end-diastolic diameter (56 [54 to 59] vs 49mm [47 to 52], p<0.01), LV end-systolic diameter (48 [43 to 51] vs 36mm [34 to 41], p<0.01), LV end-diastolic volume (71 [64 to 85] vs 56ml/m2 [46 to 68], p<0.01), LV end-systolic volume (56 [53 to 70] vs 36ml/m2 [27 to 42], p<0.01), and lower tricuspid annular plane systolic excursion (12 [10 to 13] vs 16mm [13 to 19], p<0.01). At last follow-up, LVEF was not statistically significantly different between groups. However, LV end-systolic diameter (36 [34 to 39] vs 32mm [32 to 34], p=0.01) and LV end-systolic volume (29 [26 to 35] vs 25ml/m2 [20 to 29], p=0.02) remained larger in the SeD group. Seven patients (14%), all from the SeD group, had a LVEF ≤35% 2months after rhythm control, and reverse remodeling was observed up to 9months. In conclusion, more than half of patients with tachycardia-induced cardiomyopathy and atrial flutter had LVEF ≤30% at baseline. LVEF recovery and LV remodeling were observed beyond 2months, highlighting the importance of rhythm control and early guideline-directed medical therapy in these patients.

Major in-hospital complications after catheter ablation of cardiac arrhythmias: individual case analysis of 43 031 procedures.

In-hospital complications of catheter ablation for atrial fibrillation (AF), atrial flutter (AFL), and ventricular tachycardia (VT) may be overestimated by analyses of administrative data. We determined the incidences of in-hospital mortality, major bleeding, and stroke around AF, AFL, and VT ablations in four German tertiary centres between 2005 and 2020. All cases were coded by the G-DRG- and OPS-systems. Uniform code search terms were applied defining both the types of ablations for AF, AFL, and VT and the occurrence of major adverse events including femoral vascular complications, iatrogenic tamponade, stroke, and in-hospital death. Importantly, all complications were individually reviewed based on patient-level source records. Overall, 43 031 ablations were analysed (30 361 AF; 9364 AFL; 3306 VT). The number of ablations/year more than doubled from 2005 (n = 1569) to 2020 (n = 3317) with 3 times and 2.5 times more AF and VT ablations in 2020 (n = 2404 and n = 301, respectively) as compared to 2005 (n = 817 and n = 120, respectively), but a rather stable number of AFL ablations (n = 554 vs. n = 612). Major peri-procedural complications occurred in 594 (1.4%) patients. Complication rates were 1.1% (n = 325) for AF, 1.0% (n = 95) for AFL, and 5.3% (n = 175) for VT. With an increase in complex AF/VT procedures, the overall complication rate significantly increased (0.76% in 2005 vs. 1.81% in 2020; P = 0.004); but remained low over time. Following patient-adjudication, all in-hospital cardiac tamponades (0.7%) and strokes (0.2%) were related to ablation. Major femoral vascular complications requiring surgical intervention occurred in 0.4% of all patients. The in-hospital mortality rate adjudicated to be ablation-related was lower than the coded mortality rate: AF: 0.03% vs. 0.04%; AFL: 0.04% vs. 0.14%; VT: 0.42% vs. 1.48%. Major adverse events are low and comparable after catheter ablation for AFL and AF (∼1.0%), whereas they are five times higher for VT ablations. In the presence of an increase in complex ablation procedures, a moderate but significant increase in overall complications from 2005-20 was observed. Individual case analysis demonstrated a lower than coded ablation-related in-hospital mortality. This highlights the importance of individual case adjudication when analysing administrative data.

Association of typical atrial flutter and cavotricuspid isthmus ablation on clinical recurrence after cryoballoon ablation for atrial fibrillation.

Typical atrial flutter commonly occurs in patients with atrial fibrillation (AF). Limited information exists regarding the effects of concurrent atrial flutter on the long-term outcomes of rhythm control. This study investigated the association between concurrent typical atrial flutter and cavotricuspid isthmus (CTI) ablation and the recurrence of atrial arrhythmia. The data were obtained from a multicenter registry of cryoballoon ablation for AF (n = 2,689). Patients who were screened for typical atrial flutter were included in the analysis (n = 1,907). All the patients with typical atrial flutter underwent CTI ablation. The primary endpoint was the late recurrence of atrial arrhythmia, including AF, atrial flutter, and atrial tachycardia. Among the 1,907 patients, typical atrial flutter was detected in 493 patients (25.9%). Patients with concurrent atrial flutter had a lower incidence of persistent AF and a smaller size of the left atrium. Patients with atrial flutter had a significantly lower recurrence rate of atrial arrhythmia (19.7% vs. 29.9%, p < 0.001). In patients with atrial flutter, the recurrence rate of atrial tachycardia or atrial flutter was more frequent (7.3% vs. 4.7%, p = 0.028), but the recurrence rate of AF was significantly lower (17.0% vs. 29.4%, p < 0.001). Atrial flutter has been identified as an independent predictor of the primary endpoint (adjusted hazard ratio, 0.704; 95% confidence interval, 0.548-0.906; p = 0.006). Typical atrial flutter in patients with AF may serve as a positive marker of the recurrence of atrial arrhythmia, and performing CTI ablation in this population is associated with a reduced likelihood of AF recurrence. Performing routine screening and ablation procedures for coexisting atrial flutter may improve the clinical outcomes of AF.

Application of virtual navigation in the treatment of macro-re-entrant atrial tachyarrhythmias

Macro-re-entrant atrial tachyarrhythmias occupy the leading positions in the structure of tachyarrhythmias, and one of the most common in this group is atrial flutter. These abnormal rhythms lead to a significant decrease in the quality of patients’ life, and sometimes, indirectly due to complications, can lead to disability and fatal consequences. Medical treatment for this group of arrhythmias has limited effectiveness, and the surgical method of treatment – catheter ablation – comes to the first place. Ablation of atrial flutter is traditionally performed under the guidance of fluoroscopy without the use of a navigation system, but this is associated with increased radiation exposure to patients and staff. Advances in modern arrhythmology make it possible to create anatomical models of heart chambers and activation models of the excitation spreading along anatomical models, reducing the radiation load, but requiring additional equipment and skills. Aim: to compare the procedure duration and radiation load during radiofrequency catheter ablation of the cavo-tricuspid isthmus using 3D navigation with traditional methods. Materials and methods. The work was based on the analysis of treatment results in 84 patients at National M. Amosov Institute of Cardiovascular Surgery affiliated to National Academy of Medical Sciences of Ukraine in the period from 2014 to 2021. Depending on the imaging method, patients were divided into 2 groups. Group I included 31 patients who underwent radiofrequency cavo-tricuspid isthmus (CTI) ablation according to the traditional method under fluoroscopic control without using a navigation system. Group II comprised 27 patients in whom an anatomical model of the right atrium was created. Results. Success criteria were achieved in all groups, bidirectional block line was created at the level of the CTI. In group I, the average time from the first application to the restoration of sinus rhythm was 325 ± 25 s with an average number of applications of 7.4 ± 0.6 (from 5 to 10). The average procedure time was 43.0 ± 3.3 min, with an average X-ray time of 572 ± 44 s and an average dose area product (DAP) was 62.0 ± 5.0 Gy.cm2. In group II, the total duration of the first stage of the intervention was 312 ± 26 s. The average time to stopping tachycardia and restoring sinus rhythm was 230 ± 19 s. The average time from sinus rhythm restoration to confirmation of bidirectional CTI block was 71 ± 6 s with an average number of applications of 3.2 ± 3.0 per the procedure. The average procedure time was 41.5 ± 3.5 min, the average X-ray time was 120 ± 10 s, the average DAP was 15.0 ± 1.3 Gy.cm2. Conclusions. The usage of the anatomical model of the right atrium reduces X-ray exposure by 75.8 %, in comparison to the traditional technique, during radiofrequency catheter ablation of the cavo-tricuspid isthmus with similar procedure time. The anatomical model can be recommended for ablation of the cavo-tricuspid isthmus.

Catheter ablation of typical right atrial flutter in a 20-day-old neonate with tachycardiomyopathy.

Fetal echocardiography can diagnose neonatal atrial flutter, which can cause heart failure in newborns. Little is known about catheter ablation in this population. Case report that aimed to review a successful ablation in a 20-day-old patient with refractory atrial flutter. This is the first report of a successful neonatal atrial flutter ablation without any early recurrence after the procedure. Atrial flutter ablation performed on newborns is a reliable and long-lasting treatment option.

Right-sided Atrial Flutter Ablation after Tricuspid Valve-in-Valve Replacement

Right-sided Atrial Flutter Ablation after Tricuspid Valve-in-Valve Replacement

Catheter ablation of typical atrial flutter improves cardiac chamber size and function.

Cavo-tricuspid isthmus (CTI) dependent atrial flutter (AFL) is one of the most common atrial arrhythmias involving the right atrium (RA) for which radiofrequency catheter ablation has been widely used as a therapy of choice. However, there is limited data on the effect of this intervention on cardiac size and function. A retrospective study was conducted on 468 patients who underwent ablation for CTI dependent typical AFL at a single institution between 2010 and 2019. After excluding patients with congenital or rheumatic heart disease, heart transplant recipients, or those without baseline echocardiogram, a total of 130 patients were included in the analysis. Echocardiographic data were analyzed at baseline before ablation, and at early follow-up within 1-year postablation. Follow-up echocardiographic data was available for 55 patients. Of the 55 patients with CTI-AFL, the mean age was 64.2 ± 14.8 years old with 14.5% (n = 8) female. The average left ventricular ejection fraction (LVEF) significantly improved on follow-up echo (40.2 ± 16.9 to 50.4 ± 14.9%, p < .0001), of which 50% of patients had an improvement in LVEF of at least 10%. There was a significant reduction in left atrial volume index (82.74 ± 28.5 to 72.96 ± 28 mL/m2 , p = .008) and RA volume index (70.62 ± 25.6 to 64.15 ± 31 mL/m2 , p = .046), and a significant improvement in left atrial reservoir strain (13.04 ± 6.8 to 19.10 ± 7.7, p < .0001). Patients who underwent CTI dependent AFL ablation showed an improvement in cardiac size and function at follow-up evaluation. While long-term results are still unknown, these findings indicate that restoration of sinus rhythm in patients with typical AFL is associated with improvement in atrial size and left ventricular function.

Catheter ablation for atypical atrial flutter: characterization and recurrence predictors

Abstract Background Atypical atrial flutter (AFLA) is a macro-reentrant atrial tachycardia not using the cavotricuspid isthmus. Due to recent innovations in technology, catheter ablation has emerged as the most viable option to treat AFLA. Data related to electrophysiologic characteristics and predictor prognostic factors is limited. Purpose Our study aimed to analyze long-term outcomes after catheter ablation and to identify predictors for atrial arrhythmia (AA) recurrence (documented atrial fibrillation (AF), atrial tachycardia, or atrial flutter). Methods We performed a retrospective single-center review of all consecutive patients treated for AFLA ablation in our center from October 2008 to July 2022. All patients underwent radiofrequency ablation with a 3D mapping system. Results From 64 patients (mean age 61.0 ± 11.28 years, 60.9% male and mean follow-up period (FUP) 58.5 ± 47.79 months) 32 (50.0%) had history of previous catheter ablation (35.9% PVI), 14 (21.9%) previous cardiac surgery and 18 (28.1%) corresponded to AFLA not related to ablation or previous cardiac surgery. Most patients (79.7%) had paroxysmal AFLA, 50% concomitant AF, 50% were on anthyarrhytmic drugs (AAD) and 35.9% underwent previous electrical cardioversion (ECV). Mean left ventricular ejection fraction was 55.1 ± 10.44%, 25 (39.1%) patients had moderate to severe left atrial (LA) dilatation and 11 (17.2%) right atrial (RA) dilatation. Low-voltage areas (LVA) were identified in 38 (59.4%) patients. A total of 81 AFLA were present or induced (1.3 ± 0.74 AFLA per patient) and in 7 (10.9%) patients an atrial arrhythmia was not induced. The LA was involved in 70.3% and the RA in 29­.7%. The location of the circuit is described in the table 1 as well as ablation details. Acute procedural success was achieved in 87.5%. AA recurrence occurred in 32.8% at 1 year, 35.9% at 2 years and 40.6% at FUP (14.1 ± 41.41 months after ablation), for which 3.1% had re-ablation (17.0 ± 23.99 months after index ablation), 5 (7.8%) ECV and 15 (23.4%) maintained or initiated AAD. 10 (15.6%) went to the emergency department (ED) due to AA (mean time since ablation until the first ED visit 31.4 ± 69.07 months). One patient had an ischemic stroke and 6 patients cardiovascular (CV) hospitalization. There were 5 non-CV deaths and there were no CV deaths. Female gender was an independent predictor of AA recurrence (15 (60.0%) vs 11 (31.4%), hazard ratio (HR): 3.496 [95% CI: 1.761 – 200.000], p=0.046) as well as moderate or severe LA dilatation (14 (51.9%) vs 3 (17.6%), HR 3.257 [95%CI 1.715 – 38.462], p=0.033). The presence of fibrosis or the ablation strategy were not associated with recurrence. Conclusion AFLA most frequently originated in the LA, LVA were frequent, as well as the presence of structural changes and previous ablation or cardiac surgery. In our cohort study, female gender and the severity of LA dilatation were independent predictors of AA recurrence.

Evaluation of risk factors for long-term atrial fibrillation development in patients undergoing typical atrial flutter ablation: a multi-center pilot study

Abstract Background/Introduction Atrial flutter (AFL) and atrial fibrillation (AF) are the most commonly detected supraventricular arrhythmia and share similar pathophysiological mechanisms (1). After the successful ablation of AFL, AF frequently occurs in such patients in the long-term follow up (2). As emphasized in some studies, some mechanisms seem to predispose to the development of AF in AFL patients and approximately 20% of such kind of patients have accompanying AFL (3). Purpose We aim to analyze independent risk factors that predict the development of AF in patients who underwent typical AFL ablation. Methods Our study was designed as multi-center, cross-sectional and retrospective. A total of 442 patients who underwent typical AFL ablation at 3 different centers between January 1, 2018 and January 1, 2022 were included retrospectively. The patients after the ablation procedure were divided into those who developed AF and those who did not. The patients were followed up for an average of 12 (4-20) months. In the post-procedure period, atrial arrhythmias were investigated with 24-hour Holter and ECG at 1st month, 6th month, 12th month and at 6-month intervals thereafter. Results AF developed in 206 (46.6%) patients in the long-term follow-up. Age, hypertension (HT), obstructive sleep apnea syndrome (OSAS), previous cerebrovascular accident (CVA), left atrium antero-posterior diameter, severe mitral regurgitation, hemoglobin, blood glucose and HbA1c values were found to be significant in univariable analysis. According to multivariable analysis, HT (p=0.014; HR: 1.483 (1.084 – 2.030)), OSAS (p=0.008; HR: 1.520 (1.117 – 2.068)) and previous CVA (p=0.038; HR: 1.749) (1,031 – 2,968)) were independently associated with the development of AF in AFL patients who underwent ablation procedure. Conclusion In the present study, we found that HT, OSAS and previous CVA were independently correlated with the development of AF in the long-term follow-up of patients who underwent typical AFL ablation. We consider that AFL patients with such risk factors should be followed-up closely following cavo-tricuspid isthmus ablation for the development of AF. Univariable and Multivariable Analyzes Kaplan - Meier Curves

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 (&gt;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.

Abstract 17847: Typical Right Atrial Flutter Ablation Using Subclavian Venous Access in Patients With Interrupted or Occluded Inferior Vena Cava

Introduction: Ablation for typical atrial flutter (AFL) traditionally involves vascular access from the femoral vein to facilitate advancing catheters through the Inferior Vena Cava (IVC) to the right atrium (RA). In patients with interrupted or occluded IVC, this procedure is challenging to perform. We report a case series of typical right AFL ablation using subclavian access in interrupted or occluded IVC. Cases: A 63-year-old female with typical AFL refractory to medical therapy was referred for radiofrequency ablation (RFA). She had a history of surgically corrected atrial septal defect at age 4 years with known IVC interruption draining into RA via an azygous venous extension. Another case involved a 41-year-old male with quadriplegia and typical AFL who underwent an attempted RFA from femoral access that was aborted due to massive thrombosis of IVC. Decision making: In both cases, two sheaths were placed into the left subclavian venous system using ultrasound guidance. A coronary sinus catheter and irrigated tip ablation catheter were advanced into the coronary sinus and RA respectively. Additionally, in the second case, an intracardiac echocardiography probe was inserted via separate venous access. Using the electroanatomic mapping system, entrainment and activation mapping confirmed a tricuspid isthmus-dependent AFL. RFA was performed using an open irrigated RFA catheter in a linear fashion resulting in the termination of the tachycardia to sinus rhythm. In the first case, ablation extended from the tricuspid annulus to the os of the hepatic vein at the 06:00 position. Post ablation, hemostasis was achieved using a suture-mediated closure device. At follow-up, both patients were asymptomatic without evidence of AFL on extended-duration cardiac monitoring. Conclusion: In patients with interrupted or occluded IVC, the subclavian veins can be accessed for mapping and ablation of typical AFL when traditional femoral venous access is challenging.

Abstract 12930: Atrial Myopathy and the Risk of Incident Atrial Fibrillation in People With Newly Diagnosed Cavotricuspid Isthmus-Dependent Atrial Flutter

Background New cavotricuspid isthmus-dependent atrial flutter (AFL) is associated with increased risk of incident atrial fibrillation (AF). It is unclear which patients with AFL will develop AF. Hypothesis: Patients with new AFL who have co-existing atrial myopathy, detected by measuring left atrial emptying fraction (LAEF) and left atrial reservoir strain (LARS), may be at increased risk for developing AF. Methods: There were 210 patients who received an ablation or cardioversion for AFL at a tertiary care medical center between 2015-2022. Patients were excluded for prior AF (118), congenital heart disease (16), valve surgery and heart transplant (9), no echocardiogram available (9), and less than 6 months of follow up (9). Data was obtained by retrospective chart review. Covariates included coronary heart disease, heart failure, diabetes, age, sex, vascular disease, and stroke. Exposure variables included LAEF and LARS. We used Cox proportional hazards models to estimate the risk of AF for LAEF and LARS. Results: 49 patients (mean age 62.3 years, 18.3% female) met criteria for inclusion, and 18 developed atrial fibrillation over a mean follow up period of 29.9 months (19.7 months). Those who developed AF had lower LAEF and LARS compared to those who did not. For every 5% decrease in LAEF and LARS, there was a 1.79 (1.33, 2.38) and 5.26 (1.75, 16.67)-fold increase in risk of AF after adjustment for covariates. Conclusion: Co-existing atrial myopathy, measured by decreased LAEF and LARS, is associated with increased risk of AF in people with new AFL.