Ablation Of Typical Atrial Flutter Research Articles

Ablation of CTI-dependent flutter using different ablation technologies: acute and long-term outcome from the LEONARDO study.

A novel ablation catheter has been released to map and ablate the cavo-tricuspid isthmus (CTI) in patients with atrial flutter (AFL), improving ablation efficiency. We evaluated the acute and long-term outcome of CTI ablation aiming at bidirectional conduction block (BDB) in a prospective, multicenter cohort study enrolling 500 patients indicated for typical AFL ablation. Patients were grouped on the basis of the AFL ablation method (linear anatomical approach, Conv group n = 425, or maximum voltage guided, MVG group, n = 75) and ablation catheter (mini-electrodes technology, MiFi group, n = 254, or a standard 8-mm ablation catheter, BLZ group, n = 246). Complete BDB according to both validation criteria (sequential detailed activation mapping or mapping only the ablation site) was achieved in 443 patients (88.6%). The number of RF applications needed to achieve BDB was lower in the MiFi MVG group vs both the MiFi Conv group and the BLZ Conv group (3.2 ± 2 vs 5.2 ± 4 vs 9.3 ± 5, p < 0.0001 for all comparisons). Fluoroscopy time was similar among groups, whereas we observed a reduction in the procedure duration from the BLZ Conv group (61.9 ± 26min) to the MiFi MVG group (50.6 ± 17min, p = 0.048). During a mean follow-up of 548 ± 304 days, 32 (6.2%) patients suffered an AFL recurrence. No differences were found according to BDB achieved by both validation criteria. Ablation was highly effective in achieving acute CTI BDB and long-term arrhythmia freedom irrespective of the ablation strategy or the validation criteria for CTI chosen by the operator. The use of an ablation catheter equipped with mini-electrodes technology seems to improve ablation efficiency. Atrial Flutter Ablation in a Real World Population. (LEONARDO). gov Identifier: NCT02591875.

Abstract 15879: Impact of Pulmonary Hypertension on In-Hospital Outcomes for Patients Undergoing Typical Atrial Flutter Ablation

Introduction: Pulmonary hypertension (PHT) is a progressive disease with a clinical course characterized by frequent decompensations in advanced stages. Atrial arrhythmias, including typical atrial flutter, are common in patients with PHT. We sought to investigate the effect of presence of pulmonary hypertension to the outcomes after typical atrial flutter ablation. Methods: We utilized the National Inpatient database from 2016 to 2019 to perform this study. By utilizing the ICD-10-CM codes all hospitalizations for typical atrial flutter ablation were identified. Patients with atypical flutter and ablation were excluded. Among these subjects, those with associated diagnosis of pulmonary hypertension (WHO Group 1 to 5) were identified and they formed the study group. Primary outcome was to in-hospital mortality and complications. Secondary outcomes included analysis of patient clinical characteristics, length of hospital stay (LOS) and total hospital charges (TOTCH). Multivariate regression analysis was used to predict outcomes. Results: A total of 7,784 patients with PHT were hospitalized for typical atrial flutter ablation during the study period. Patients with PHT were slightly older (66 vs 67 years, p&lt;0.001). The proportion of males was lower in the PHT group (57vs 67 %, p&lt;0.001). For Typical AFL patients undergoing ablation, the presence of PHT was associated with higher odds of mortality (a0R= 1.8, p=0.003), acute kidney injury (a0R= 1.6, p&lt;0.001), heart failure exacerbation (a0R= 1.3, p&lt;0.001) and cardiogenic shock (a0R= 2.2, p&lt;0.001) on multivariate regression analysis. They also had higher LOS (+2.3 days, p&lt;0.001) and TOTCH (+$30,501, p&lt;0.001). Conclusion: Our data shows that pulmonary hypertension is independently associated with worse in-hospital outcomes in patients undergoing typical atrial flutter ablation, including higher mortality. Further prospective studies are required to confirm our findings.

Novel "red-bull sign" during cavotricuspid isthmus ablation: Indication of an ablation catheter stuck in the subeustachian pouch.

A subeustachian pouch (SEP) often hinders the completion of a cavotricuspid isthmus (CTI) ablation of typical atrial flutter (AFL) and sometimes causes steam-pops during a power-controlled ablation. We hypothesized that real-time bull's-eye monitoring of the catheter surface temperature might be useful to locate the SEP where the temperature can rise rapidly, and a temperature-controlled ablation might avoid steam pops. This study aimed to demonstrate this hypothesis. A temperature-controlled CTI ablation with a QDOT MICRO™ catheter (n=10) and a conventional power-controlled CTI ablation (n=10) were performed with an output power of 35 W. During the RF application, the bull's eye monitor for monitoring the catheter surface temperatures was assessed. A "red-bull sign" was defined as an entire red-colored bull's-eye monitor, indicating that the catheter-tip temperature of all 6 thermocouples rose rapidly over 47°C. In a total of 115 lesions (12 ± 3 per patient), a "red-bull sign" was observed in 39 (33.9%) lesions where the RF output was reduced to 26 ± 8W. All 39 "red-bull sign" lesions corresponded to the location of the SEP as delineated by ICE before the ablation. The red-bull sign accurately indicated the presence of a SEP with a sensitivity of 84.7% and specificity of 100%. Bidirectional block of the CTI was completed in all patients in either catheter group without any steam-pops. Real-time surface temperature monitoring and a red-bull sign might be useful to detect the SEP. A temperature-controlled CTI ablation with the QDOT MICRO catheter might be safe for avoiding steam pops.

A novel wide-band dielectric imaging system to guide radiofrequency ablation for pulmonary vein isolation.

Recently, the wide-band dielectric mapping system Kodex-EPD was introduced. This study reports the first clinical experience using a novel system to guide pulmonary vein isolation (PVI) with radiofrequency (RF)ablation. METHODSAND RESULTS: The study included 20 consecutive patients undergoing de-novo PVI for symptomatic paroxysmal or persistent atrial fibrillation guided by Kodex-EPD. The primary efficacy endpoint was successful PVI. Secondary endpoints included procedural parameters and complications. In all 20 patients (mean age 68 ± 8 years, 12 male patients, paroxysmal fibrillation in 14/20 [70%] patients), PVI was successfully completed. One patient underwent additional cavo-tricuspid isthmus ablation for concomitant typical atrial flutter and one patient required additional ablation of a focal atrial tachycardia. A conventional three-dimensional image of the left atrium as well as the innovative endocardial panoramic view were used to guide catheter manipulation and ablation. Median procedure time was 115 [1st; 3rd quartile 93,75; 140] min and median total fluoroscopy time was 9.9 [9.7; 11.2] min, of which a median of 0.8 [0.6; 0.9] min was required to create left atrial maps. Complete left atrial imaging using Kodex-EPD was achieved within a median of 7.1 [5.7; 8.3] min. Median RFablation time was 45.1 [34.6; 58.7] min. No major complications were observed. RF ablation PVI guided by Kodex-EPD seems safe and feasible. The system provides effective three-dimensionalguidance for PVI.

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.

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.

Cuantificación de la fibrosis auricular derecha mediante resonancia magnética cardiaca: verificación del método para la estandarización de umbrales

Introduction and objectivesLate gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) allows noninvasive detection of left atrial fibrosis in patients with atrial fibrillation (AF). However, whether the same methodology can be used in the right atrium (RA) remains unknown. Our aim was to define a standardized threshold to characterize RA fibrosis in LGE-CMR. MethodsA 3 Tesla LGE-CMR was performed in 53 individuals; the RA was segmented, and the image intensity ratio (IIR) calculated for the RA wall using 1 557 767 IIR pixels (40 994±10 693 per patient). The upper limit of normality of the IIR (mean IIR+2 standard deviations) was estimated in healthy volunteers (n=9), and patients who had undergone previous typical atrial flutter ablation (n=9) were used to establish the dense scar threshold. Paroxysmal and persistent AF patients (n=10 each) were used for validation. IIR values were correlated with a high-density bipolar voltage map in 15 patients undergoing AF ablation. ResultsThe upper normality limit (total fibrosis threshold) in healthy volunteers was set at an IIR = 1.21. In the postablation group, 60% of the maximum IIR pixel (dense fibrosis threshold) was calculated as IIR = 1.29. Endocardial bipolar voltage showed a weak but significant correlation with IIR. The overall accuracy between the electroanatomical map and LGE-CMR to characterize fibrosis was 56%. ConclusionsAn IIR > 1.21 was determined to be the threshold for the detection of right atrial fibrosis, while an IIR > 1.29 differentiates interstitial fibrosis from dense scar. Despite differences between the left and right atria, fibrosis could be assessed with LGE-CMR using similar thresholds in both chambers.

Typical Atrial Flutter Mapping and Ablation.

Isthmus-dependent flutter represents a defeated arrhythmia. Possibly one of the most outstanding successes in terms of understanding the mechanism behind it has led to an effective, relatively simple, and safe targeted therapy. Technology, fulfilling a number of the clinical electrophysiologist's dreams, has linked diagnosis and therapy in computerized systems showing real-time imagines of the right atrium, the arrhythmia circuit, and the ablation target. The entire history of clinical electrophysiology is contained in its path and atrial flutter needs to be regarded with immense respect for a large amount of knowledge that its study always engenders."

Quantification of right atrial fibrosis by cardiac magnetic resonance: verification of the method to standardize thresholds

Introduction and objectivesLate gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) allows noninvasive detection of left atrial fibrosis in patients with atrial fibrillation (AF). However, whether the same methodology can be used in the right atrium (RA) remains unknown. Our aim was to define a standardized threshold to characterize RA fibrosis in LGE-CMR. MethodsA 3 Tesla LGE-CMR was performed in 53 individuals; the RA was segmented, and the image intensity ratio (IIR) calculated for the RA wall using 1 557 767 IIR pixels (40 994±10 693 per patient). The upper limit of normality of the IIR (mean IIR+2 standard deviations) was estimated in healthy volunteers (n=9), and patients who had undergone previous typical atrial flutter ablation (n=9) were used to establish the dense scar threshold. Paroxysmal and persistent AF patients (n=10 each) were used for validation. IIR values were correlated with a high-density bipolar voltage map in 15 patients undergoing AF ablation. ResultsThe upper normality limit (total fibrosis threshold) in healthy volunteers was set at an IIR = 1.21. In the postablation group, 60% of the maximum IIR pixel (dense fibrosis threshold) was calculated as IIR = 1.29. Endocardial bipolar voltage showed a weak but significant correlation with IIR. The overall accuracy between the electroanatomical map and LGE-CMR to characterize fibrosis was 56%. ConclusionsAn IIR > 1.21 was determined to be the threshold for the detection of right atrial fibrosis, while an IIR > 1.29 differentiates interstitial fibrosis from dense scar. Despite differences between the left and right atria, fibrosis could be assessed with LGE-CMR using similar thresholds in both chambers.

The role of interventional cardiac magnetic resonance (iCMR) in a typical atrial flutter ablation: The shortest path may not always be the fastest.

The role of interventional cardiac magnetic resonance (iCMR) in a typical atrial flutter ablation: The shortest path may not always be the fastest.

Experience of Combined Procedure during Percutaneous LAA Closure.

Introduction: Percutaneous left atrial appendage closure (LAAC) is an alternative to oral anticoagulants (OAC) in patients with non-valvular atrial fibrillation (AF) and contraindication to long-term OAC. Combined strategy with percutaneous LAAC at the same time of other cardiac structural or electrophysiological procedures has emerged as an alternative to a staged strategy. Aim: To describe our experience with combined LAAC procedures using Watchman™ devices. Methods: All patients with combined LAAC procedures using Watchman™ (WN) devices performed from 2016 to 2021 were included. The primary safety endpoint was a composite of periprocedural complications and adverse events during the follow-up. The primary efficacy endpoint included strokes, systemic embolisms, major bleeding and cardiovascular death. Results: From 2016, among 160 patients who underwent LAAC using WN devices, 19 underwent a combined strategy: 7 transcatheter edge-to-edge mitral valve repair (TEMVR) (37%), 6 typical atrial flutter ablation (31%), 2 leadless pacemaker (LP) implantation (10%) and 4 AF ablation (22%). The WN device was successfully implanted in 98% and 100% of cases for single and combined LAAC procedures, respectively (p = 0.63). Median follow-up was 13 months (IQR 25/75 3/24). Device-related complications occurred in 6 out of 141 patients (4%) who underwent single LAAC and in no (0/19) patient in the combined LAAC procedure (p = ns). The procedural-related complications did not differ significantly between groups (5% vs. 10%, respectively, in the single and combined group, p = 0.1). Conclusion: Combined procedure using the Watchman™ devices and one other structural or electrophysiological procedure appears safe and effective. Larger series are needed to confirm these results.

Zero fluro compared to fluoroscopy guided radiofrequency ablation of typical atrial flutter

Abstract Funding Acknowledgements Type of funding sources: None. Background There is growing evidence of the harm caused by radiation exposure for both patients and health professionals. Current use of electroanatomical 3D mapping systems has allowed the application of zero fluro technique in order to reduce exposure. The efficacy and accuracy of these mapping systems is becoming more apparent, reserving traditional fluoroscopic techniques for simple anatomical cases. Hence, the use of radiation with no electroanatomical mapping for the ablation of typical flutter, still remains the mainstay of treatment in most centers. Purpose We aimed to investigate whether a zero fluro approach in typical atrial flutter ablation results in similar outcomes compared to traditional fluoroscopic techniques. Methods This was a single center retrospective study of (n=388) consecutive patients undergoing typical atrial flutter ablation between 2018 and 2020. Majority of cases were performed under conscious sedation (i.v. midazolam and fentanyl) with two sheaths into the right femoral vein under ultrasound guidance. A steerable Livewire™ quadripolar or an Inquiry™ deccapolar diagnostic catheter was advanced into the coronary sinus. 3D mapping was performed with Ensite Precision™ or Carto 3™. Fluoroscopy was performed in LAO 300 with ablation performed at 6 o’clock on the tricuspid annulus back to inferior vena cava. Ablation catheters used 30-60 seconds per lesion. Procedural endpoints included a bidirectional block across cavotricuspid isthmus and clinical and electrocardiographical recurrence during follow up at 3 months. Baseline characteristics were examined for confounders. Results Atrial flutter ablation was successful in 95% of the procedures with no difference between the two groups (p=0.07). There was a significant exposure to radiation (2.494 ± 3.596 gy/cm² vs 0.1 ± 0.7 gy/cm², p=0.001) and in total fluoroscopy time (8 ± 5.7 min vs 0 ± 0 min, p=0.001) in the fluro guided group compared to zero fluro group. Total ablation time was not significantly different between the two groups (16.1 ± 11.6 min vs 14.7 ± 10.2 min, p=0.40). Patients undergoing fluro guided ablation had a significantly longer procedure when compared to the zero fluro group (77.4 ± 44.8 min vs 66.1 ± 37.1 min, p=0.006). There was no difference in baseline characteristics or procedural complications between the two groups (table 1). Conclusion Ablation of typical atrial flutter can be performed safely and effectively with zero fluro techniques using only 3D anatomical mapping. This work adds to the growing body of evidence to support the use of these technologies in the management of simple cardiac arrhythmias, in order to eliminate the use of radiation and its effect in carcinogenesis, by making them current standard of care.

Fluoroless cavotricuspid isthmus radiofrequency ablation of typical atrial flutter achieves success with zero radiation and shorter procedural duration

Abstract Funding Acknowledgements Type of funding sources: None. Background Cavotricuspid isthmus (CTI) ablation in patients with typical atrial flutter (AFL) has improved in the past years, especially by the use of threedimensional (3D) electroanatomic mapping systems. These mapping tools contributed to reduce radiation exposure, but most ablation procedures still require varying amounts of fluoroscopy. Purpose We aim to examine whether fluoroless CTI ablation is effective and safe in reducing AFL recurrence, compared with CTI ablation using fluoroscopy and a 3D mapping system. Methods A retrospective analysis of CTI ablation procedures performed at a tertiary center between December 2008 and December 2020 was conducted. Cases were divided in two groups: fluoroless and fluoroscopic, according to the use of radiation. Procedural duration, fluoroscopy time (FT), use of 3D mapping system, complications and recurrence rate at one year were analyzed. Results A total of 324 CTI ablations performed on patients with documented typical AFL were included. Mean age was 62.3±14.0, with 78.1% male patients. Fluoroless ablations were performed based on a 3D mapping system, and all fluoroscopic procedures also used 3D electroanatomic mapping. The FT was zero in the fluoroless group - 31 cases (9.6%), and 7.0±4.4 minutes in the fluoroscopic group - 291 cases (90.4%) (p&amp;lt;0.001). There was no statistically significant difference between the two groups, regarding AFL recurrence at one year (21.7% in the fluoroless group versus 13% in the fluoroscopic group; odds ratio [OD] 0.54; 95% confidence interval [CI] 0.18-1.62; p=0.27). Total procedure duration was significantly shorter in the fluoroless group (1h07m versus 1h40m; t-test 4.261, p&amp;lt;0.001, CI 0h16m-0h50m). There were no acute complications for both groups. Conclusion Fluoroless CTI ablation avoids radiation exposure to the patient and operator and can be performed in patients with typical AFL, without compromising duration, safety or efficacy of the procedure.

Direct pre- and post-ablation cardiac magnetic resonance imaging of tissue characteristics in patients with typical atrial flutter

Abstract Funding Acknowledgements Type of funding sources: None. Background Real-time cardiac magnetic resonance (CMR) imaging as guidance in electrophysiology (EP) procedures enables a detailed overview of the anatomy of the heart and surrounding structures, active and passive catheter tracking, and real-time visualisation of ablation lesions throughout the ablation procedure, without using fluoroscopy. Purpose To evaluate ablation induced changes in tissue characteristics of the cavotricuspid isthmus (CTI), directly following typical atrial flutter ablation in an interventional cardiac magnetic resonance (iCMR) suite. Methods Nine patients with symptomatic typical atrial flutter were referred for CTI ablation in an iCMR suite. Procedures were performed using a 1.5T MRI scanner. Pre-ablation imaging included T2-weighted edema imaging in the right anterior oblique (RAO) and transversal view. During the ablation procedure, CMR imaging facilitated active tracking and real-time navigation of both diagnostic and ablation catheters, as well as visualisation of the ablated tissue. Post-ablation imaging to evaluate the target tissue again included T2-weighted edema imaging as well as dark-blood late gadolinium enhancement (LGE) imaging. Data regarding post-ablation imaging findings, ablation outcome, and complications were collected for all patients. All patients provided written informed consent. Results In eight of the nine patients, T2-weighted imaging was successfully performed pre- and post-ablation, which identified myocardial edema at the CTI ablation line in all patients (Figure 1A-B). Due to time restraints, post-ablation LGE imaging was performed in five patients, which showed pathological signal intensity at the level of the CTI in all five patients (Figure 1C). Bidirectional block of the CTI was confirmed by differential pacing in eight patients. No complications occurred during or immediately after the procedures. In one patient, the registration of intracardiac electrograms was not possible due to technical problems and the patient was transferred to a conventional EP lab to complete the ablation following our predefined bailout procedure. Conclusion Real-time CMR guided CTI ablation in patients with typical atrial flutter is safe and successful. CMR enables accurate visualisation of the CTI line and provides immediate post-ablation evaluation of tissue characteristics at the ablation target location. Figure 1. T2-weighted edema cardiac magnetic resonance (CMR) imaging in the right anterior oblique (RAO) view acquired pre- (A) and post-ablation (B) during interventional CMR ablation therapy. Late gadolinium enhancement (LGE) CMR in the RAO view post-ablation (C) of the same patient. The blue arrowheads indicate the cavotricuspid isthmus (CTI) line. High signal intensity at the level of CTI is observed post-ablation on both T2-weighted (indicating edema) and LGE (indicating cell membrane rupture) images.

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.

Single-center outcome after ablation of atrial fibrillation using very high-power short duration pulmonary vein isolation

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation of atrial fibrillation is (AF) an established second line therapy for patients with symptomatic paroxysmal (PAF) and persistent AF (persAF). Novel ablation catheters with integrated thermocouples allow fast application of radiofrequency lesions with powers up to 90W. We aimed to describe primary and secondary outcomes after very high-power short duration (vHPSD) ablation. Methods 126 consecutive patients (78 PAF, 43 persAF, 5 longstanding persistent AF) underwent pulmonary vein isolation (PVI) using the QDOT Micro Catheter (Biosense Webster) with the ablation mode QMODE+ (90W, 4s, interlesion distance ≤4mm anterior, ≤6mm posterior). Results Mean age was 62±9 years, 33% were female, median CHA2DS2-VASc Score was 2 (0, 7). Median follow up duration was 204 (14, 461) days. 30% of patients had additional ablation of typical right atrial flutter. Primary success rate to achieve pulmonary vein isolation was achieved in all patients, no catheter-related complications (e.g., charring, steam pop) occurred. First pass isolation of all 4 PVs was achieved in 48% of patients, re-ablations were necessary in the carina regions (right: 37% of cases, left: 29%) and ridge (14%). Median procedure for PVI only were 102 (45-210) minutes. Arrhythmia-free survival was 79,6% (see Figure 1). Eight patients underwent re-do procedures during follow-up showing most commonly showing gaps in the right inferior PV (63%) and ridge (50%). Conclusion Very high-power short duration ablation allows safe and quick pulmonary vein isolation. However, first pass isolation rate is low due to gaps in the carina regions. Arrhythmia-free survival is comparable to other pulmonary vein isolation techniques. Figure 1: Left panel: Sample image of a vHPSD-PVI, posterior view of the left atrium. Right panel: Single procedure arrhythmia-free survival after vHPSD-PVI.

Very high-power short-duration temperature-controlled ablation for cavotricuspid isthmus block : the Fast-and-Furious CTI study

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation for typical right atrial flutter (AFL) provides an effective treatment associated with encouraging clinical outcome. The novel micro-electrode ablation catheter allows very high-power short-duration (vHP-SD, 90 W/4 sec) ablation and potentially offers the ability to perform a safe, effective and faster cavotricuspid isthmus (CTI) ablation. Aims We evaluated feasibility and efficacy of a vHP-SD (90 W/4 sec) temperature-controlled radiofrequency (RF) CTI ablation for AFL using a novel contact force (CF) sensing ablation catheter with micro-electrodes. Methods Fifteen consecutive patients (median age 75 years (interquartile range, IQR: 67, 79), 67 % male) with documented typical AFL were prospectively enrolled and underwent vHP-SD based CTI ablation (90 W/4 sec). Durability of CTI block was proven by pacing maneuvers from both sides of the ablation line. Results Complete CTI block using vHP-SD ablation was achieved in all patients (Figure 1). At median 23 (IQR 20; 39) RF applications over a median RF ablation time of 92 (IQR 78, 154) seconds were applied. It was not necessary to switch to the standard temperature-controlled mode to achieve durable CTI block. No periprocedural complications, no charring and no steam pops were observed. Conclusions Very high-power short-duration (90 W/4 sec) CTI ablation for the treatment of typical AFL is feasible and efficient. Effective CTI block can be achieved in about 1.5 minutes of RF time.

Atrial Fibrillation in a Patient with Interatrial Block after Successful Atrial Flutter Ablation: May Interatrial Block Be a Link for a Continuum of Atrial Arrhythmias?

Background: Electrocardiographic interatrial block (IAB) typically exists when a conduction delay over the Bachmann’s bundle is present. By analogy to other types of block, there is a continuum of IAB severity; partial IAB is defined as a P-wave duration 120 ms and advanced interatrial block (aIAB) is defined as a P-wave duration 120 ms in conjunction with biphasic P-wave morphology in inferior leads II, III, and aVF. Moreover, IAB seems to be a key factor in the genesis of atrial fibrillation (AF). On the contrary, it is not clear if the presence of advanced IAB may be associated with an occurrence of AF after cavotricuspid atrial flutter ablation in patients without previous episodes of atrial fibrillation. So, may be useful to evaluate on surface electrocardiogram the P-wave morphology and duration in sinus rhythm after the ablation procedure just to identify patients at high risk for atrial fibrillation development. Advanced IAB is frequently associated with atrial tachyarrhythmias, and it was found to predict AF and may be helpful for clinical decisions. Case presentation: In this case involving a man who underwent a typical atrial flutter ablation, we documented that aIAB during the post-ablation period which seems to induce atial fibrillation episodes. To our knowledge, it is unusual to detect an aIAB after cavotricuspid atrial flutter ablation and subsequently associate it with a new onset of AF. Conclusions: Our observation supports a possible aIAB induction of AF after cavotricuspid atrial flutter ablation and potentially may representing a link in the continuum of atrial arrhythmias. P-wave morphology and duration should be better evaluated soon after AFlu ablation to better stratify patients who are at high risk for atrial fibrillation development and eventually prolonged anti-coagulation therapy.

Ablation of typical atrial flutter as therapeutic component in carcinoid heart disease: a case report

BackgroundCarcinoid heart disease is the cardiac manifestation of carcinoid syndrome. There is limited research on rhythm management in patients with carcinoid heart disease. The association of typical atrial flutter and carcinoid heart disease in particular is poorly described.Case presentationHere we present a case of a 77-year-old German woman with carcinoid heart disease and recurrent typical atrial flutter complicating the postoperative course after tricuspid valve replacement and its successful long-term rhythm control by ablation therapy.ConclusionThere is limited evidence on rhythm management in patients with the rare diagnosis of carcinoid heart disease. Typical atrial flutter repeatedly complicated the postoperative course of our patient with carcinoid heart disease and could finally be treated curatively by ablation. Radiofrequency ablation should be considered as a valuable therapeutic component in the challenging therapy of this disease.

Recurrent atrial arrhythmia in a randomised controlled trial comparing contact force-guided and contact force-blinded ablation for typical atrial flutter.

Contact force (CF)-guided catheter ablation (CA) is a novel technology developed to improve efficacy and reduce complications. In a randomised controlled trial (RCT), we previously documented that after 3months, rate of persistent conduction block was similar with and without using CF while performing CA for typical atrial flutter (AFL). Clinical effect of CF on recurrent arrhythmia is unknown. Our objective is to study recurrent atrial arrhythmia during 12-month follow-up in a RCT investigating whether CF-guided CA for typical AFL is superior to CF-blinded CA. Patients were randomised 1:1 to CA guided by CF (intervention group) or blinded to CF (control group). After 12months, patients attended clinical check-up preceded by a 5-day ambulatory Holter monitor recording. Primary outcome was any recurrent atrial arrhythmia ≥ 30s within 12months and documented in 12-lead ECG or Holter monitor recording. We included 156 patients, four patients withdrew consent and two died during follow-up. Thus, 150 patients were included in final analysis. Recurrent arrhythmia was detected in 36 of 77 (47%) patients in the intervention group, and 32 of 73 patients (44%) in the control group (p = 0.51). Atrial fibrillation was detected in 23 (30%) and 29 (40%) patients in the intervention and control groups respectively. AFL was detected in 11 (14%) and 5 (7%) patients in the intervention and control groups respectively. Contact force-guided ablation for typical atrial flutter does not reduce recurrent atrial arrhythmia after 12-month follow-up as compared with ablation blinded for contact force.