Ablation Of Focal Atrial Tachycardia Research Articles

Prognostic factors for the effectiveness of catheter ablation of focal atrial tachycardia in school-age children: data from a single-center registry study

Prognostic factors for the effectiveness of catheter ablation of focal atrial tachycardia in school-age children: data from a single-center registry study

Comparison of safety and effectiveness of different sheaths in ablation of focal atrial tachycardia: a retrospective study.

A novel visualized steerable sheath, referred to as the Vizigo sheath, has been utilized in clinical interventions. The objective of this study was to evaluate and contrast the efficacy and safety of the Vizigo sheath with other sheaths in the catheter ablation (CA) for focal atrial tachycardia (FAT). A retrospective cohort study was conducted on consecutive patients with CA for FAT from March 2019 to February 2022. Objectives were to assess the impact of the Vizigo sheath on acute and long-term ablation success rates, procedural and fluoroscopy times, and contact force (CF). A total of 164 patients, mean age 50±15 years, 97 (59.1%) women, underwent CA of FAT using the Vizigo sheath (N=42), non-visualized steerable sheath (N=36), or other conventional sheath (N=86). Age, sex, body mass index (BMI), presence of hypertension, heart failure, and diabetes mellitus were not significantly different among the three groups. The acute success rate of 94.0% was similar among the three groups. Over a follow-up of 14±2 months, the Vizigo sheath was associated with superior arrhythmia-free survival (88.1%) when compared to non-visualized steerable (69.4%; P=0.04) and other conventional (72.1%, P=0.046) sheaths. Procedural duration, number of ablation lesions, and ablation times were similar among the three groups. However, the Vizigo sheath was associated with lower fluoroscopy times (e.g., 145 vs. 250 s with Vizigo versus non-visualized steerable sheaths, P=0.03) and higher CF (e.g., average CF 12.0 versus 8.0 g with Vizigo versus non-visualized steerable sheaths, P=0.003). The application of Vizigo sheath can improve the long-term success rate of FAT and reduce the radiation exposure of patients and medical staff in our single-center limited sample study. More research may be needed in the future to confirm our findings.

Abstract 17192: Characterization and Localization of Focal Atrial Tachycardia in Adult Congenital Heart Disease

Introduction: Patients with adult congenital heart disease (ACHD) often develop atrial arrhythmias, including focal atrial tachycardia (FAT). In non-ACHD patients, algorithms using surface ECG P-wave morphology are helpful to predict FAT location to assist in planning targeted ablation procedures, but similar algorithms have not been fully developed for ACHD patients with complex anatomy, including prior surgical correction and other anatomic differences. Methods: In this single-center retrospective cohort study, 29 patients with ACHD who underwent catheter ablation for FAT were included. FAT P-waves from 12-lead electrocardiograms obtained in clinic or the electrophysiology laboratory were classified as 1) positive, 2) negative, 3) isoelectric, or 4) biphasic. FAT ablation sites identified by electroanatomic mapping were grouped by region: right atrium (RA), paraseptal (PS), and left atrium (LA). Accuracy of P-wave classification criteria to predict FAT region were determined. Results: Thirty FATs were assessed in 29 patients (mean age 47 +/- 16 yrs, female 55%). RA FAT sites: crista terminalis (14), Fontan baffle (3) non-septal tricuspid annulus (1). PS FAT sites: PS tricuspid annulus (2), coronary sinus ostium (3), foramen ovale (1). LA FAT sites: mitral annulus (2), right superior pulmonary vein (1), left atrial appendage (3). Based on previously reported P-wave morphology localization criteria in normal hearts, sensitivities and specificities were analyzed in these ACHD patients and are shown in the Table. Additional algorithms were also tested. We determined that a biphasic (+/-) or negative P-wave in lead V1 was associated with a 100% specificity for the RA compared to PS or LA. Conclusions: P-wave morphology may be useful in predicting atrial location of FAT in ACHD patients. Similar to patients with normal hearts, lead V1 P-wave morphology in ACHD patients provides the most useful information for localizing FAT with a high degree of specificity.

Paced P-wave morphology templates to guide atrial tachycardia localization: A derivation and validation study.

Surface ECG is a useful tool to guide mapping of focal atrial tachycardia (AT). We aimed to construct 12-lead ECG templates for P-wave morphology (PWM) during endocardial pacing from different sites in both atria in patients with no apparent structural heart disease (derivation cohort), with the goal of creating a localization algorithm, which could subsequently be validated in a cohort of patients undergoing catheter ablation of focal AT (validation cohort). We prospectively enrolled consecutive patients who underwent electrophysiology study, had no structural heart disease and no atrial enlargement. Atrial pacing, at twice diastolic threshold, was carried out at different anatomical sites in both atria. Paced PWM and duration were assessed. An algorithm was generated from the constructed templates of each pacing site. The algorithm was applied on a retrospective series of successfully ablated AT patients. Overall and site-specific accuracy were determined. Derivation cohort included 65 patients (25 men, age 37±13 years). Atrial pacing was performed in 1025 sites in 61 patients (95%) in RA and in 15 patients (23%) in LA. The validation cohort included 71 patients (28 men, age 52±19 years). AT were right atrial in 66.2%. The algorithm successfully predicted AT origin in 91.5% of patients (100% in LA and 87.2% in RA). It was off by one adjacent segment in the remaining 8.5%. A simple ECG algorithm based on paced PWM templates was highly accurate in localizing site of origin of focal AT in patients with structurally normal hearts.

10-year single center experience of catheter ablation of focal atrial tachycardia.

Focal atrial tachycardias (ATs) represent 5-15% of sustained supraventricular tachycardias (SVTs). Characteristic distribution of sites of origin and detailed electrophysiologic characterization of AT from specific sites of origin (SOO) have been described. Acute success and recurrence are less favorable than for other SVTs. In this series, we present our experience of focal AT ablation over a 10-year period. We undertook a retrospective review of an electronically maintained database of all patients undergoing AT ablation at our institution between January 2011 and December 2020. Demographic, procedural, and outcomes data were reviewed. A total of 293 distinct atrial tachycardias were treated during 279 procedures in 256 patients, including 207 first AT ablations. Acutely successful AT suppression was achieved in 91% of first-time ablations. Acute success was dependent on SOO of AT with lowest rates of acute suppression in the para-Hisian region and the crista terminalis (CT). The most common reason for failure to acutely suppress the AT was proximity to a critical structure (phrenic nerve, sinus node, and AV node). 8.9% of patients in this series presented with a tachycardia-mediated cardiomyopathy (TCM). 48% of TCM patients underwent an ablation attempt during an acute medical admission. Among the TCM group, median LV ejection fraction increased from 25% (range 10-50%) to 55% (range 35-65%) with successful treatment of AT. Five patients undergoing a repeat procedure had planned pericardial access for displacement of the phrenic nerve to permit ablation of the AT, which was successful in all cases. Among patients without a pre-existing diagnosis of AF, peri-procedural AF was not associated with a higher incidence of a subsequent diagnosis of AF (odds ratio 1.169, 95% CI 0.4058-3.475, p = 0.7628). Median duration of follow-up was 832days. By Kaplan-Meier estimate, recurrence-free survival was 78% (95% CI 67-88%). In this series, focal AT ablation is associated with good acute results and a low rate of complications, but outcomes remain less favorable than previously reported for other forms of SVT.

Ablation index predicts outcomes of catheter ablation of focal atrial tachycardia: results of a multicenter study

Abstract Funding Acknowledgements Type of funding sources: None. Background Ablation index (AI) is a radiofrequency energy lesion quality marker integrating power, contact force, and time, which was recently shown to be linked to successful catheter ablation (CA) of atrial fibrillation, atrial flutter, and premature ventricular complexes. The possible role of AI as a predictor of outcomes after CA of focal atrial tachycardia (AT) has not been explored so far. Purpose To evaluate the role of AI as a predictor of arrhythmia-free survival after CA of focal AT. Methods We retrospectively enrolled forty-five consecutive patients undergoing CA for focal AT in four referral Italian electrophysiology laboratories. Clinical and procedural information were collected. For each patient, maximum and mean (by averaging maximum AI values for each radiofrequency ablation lesion) values of AI were measured. Focal AT-free survival was the primary outcome, and was assessed with repeated Holter monitors or cardiac implantable electronic devices, when available. The Shapiro-Wilk’s test was used to check continuous variables for normality; non-normal variables were expressed as median (1st-3rd quartile), whereas categorical variables were reported as counts and percentages. The primary outcome was assessed in a time-to-event fashion, with the Kaplan-Meier method, and the role of AI as a predictor of focal AT recurrence was tested with univariable Cox proportional hazard regression. Furthermore, differences in AI values between patients experiencing a primary outcome event and patients not experiencing a primary outcome event were analyzed with the Student t test. Discrimination ability of AI was measured with area under the receiver operating characteristic curve, and the optimal AI cutoff value was identified with Youden’s index. An alpha level <0.05 was considered statistically significant, and the software RStudio (RStudio Inc., Boston, MA) was used for statistical analysis. Results CA was acutely effective in every patient; however, 20% (n=9) of the study population had a focal AT recurrence over a median follow-up of 288 (160-560) days. Both maximum and mean AI values were significantly higher among patients without AT recurrences (maximum AI=568±91, mean AI=426±105) than in patients with AT relapses (maximum AI=447±142, mean AI=352±76, p=0.036 and p=0.028, respectively). All other procedural parameters were similar between the two groups. In a time-to-event analysis, only maximum AI was significantly associated with survival free from AT recurrence (p=0.001, Figure), whereas mean AI was not (p=0.08). By receiver operating characteristic (ROC) curve analysis, the optimal maximum AI cutoff for predicting effective CA according to Youden’s index was 461 (sensitivity, 0.89; specificity, 0.56). Conclusion We observed a strong association between maximum AI and outcomes, suggesting that maximum AI may be regarded as a quantitative marker of successful CA of focal AT.

Ablation Index Predicts Successful Ablation of Focal Atrial Tachycardia: Results of a Multicenter Study.

A radiofrequency energy lesion transmurality marker incorporating power, contact force, and time (Ablation Index, AI) was shown to be associated with outcomes of catheter ablation (CA) of multiple arrhythmias, but was never systematically assessed in the CA of focal atrial tachycardias (AT). We aimed to evaluate the role of AI as a predictor of outcomes in focal AT CA, and therefore, retrospectively included 45 consecutive patients undergoing CA for focal AT in four referral electrophysiology laboratories. Clinical and procedural information were collected. For each patient, maximum and mean (by averaging maximum AI values for each radiofrequency ablation lesion) AI were measured. The primary outcome was focal AT-free survival, and was systematically assessed with periodical Holter monitors or cardiac implantable electronic devices. CA was acutely effective in each case; however, 20% (n = 9) of the study population experienced a focal AT recurrence over a median follow-up of 288 days. Both maximum and mean AI values were significantly higher among patients without AT recurrences (maximum AI = 568 ± 91, mean AI = 426 ± 105) than in patients with AT relapses (maximum AI = 447 ± 142, mean AI = 352 ± 76, p = 0.036, and p = 0.028, respectively). The optimal cutoffs associated with freedom from recurrences were 461 for maximum AI (sensitivity, 0.89; specificity, 0.56) and 301 for mean AI (sensitivity, 0.97; specificity, 0.44). In a time-to-event analysis, maximum AI was significantly associated with survival free from AT recurrence (p = 0.001), whereas mean AI was not (p = 0.08). In summary, maximum AI is the best procedural parameter associated with the outcomes of CA for focal AT, and may help standardize the procedural approach.

Single-center experience of ultra-high-density mapping guided catheter ablation of focal atrial tachycardia.

IntroductionCatheter ablation is the treatment of choice for recurrent focal atrial tachycardia (FAT) as medical therapy is limited. Routinely, a three‐dimensional mapping system is used. Whether or not optimized signal detection does improve ablation success rates has not yet been investigated. This retrospective cohort study compared ablation procedures using an ultra‐high‐density mapping system (UHDM, Rhythmia, Boston Scientific) with improved signal detection and automatic annotation with procedures using a conventional electroanatomic mapping system (CEAM, Biosense Webster, CARTO).MethodsAll patients undergoing ablation for FAT using UHDM or CEAM from April 2015 to August 2018 were included. Endpoints comprised procedural parameters, acute success as well as freedom from arrhythmia 12 months after ablation.ResultsA total of 70 patients underwent ablation (48 with UHDM, 22 with CEAM). No significant differences were noted for parameters like procedural and radiation duration, area dose, and RF applications. Acute success was significantly higher in the UHDM cohort (89.6% vs. 68.2%, p = .03). Nevertheless, arrhythmia freedom 12 months after ablation was almost identical (56.8% vs. 60%, p = .87), as more patients with acute success of ablation presented with a relapse during follow‐up (35.0 vs. 7.7%, p = .05).ConclusionAcute success rate of FAT ablation might be improved by UHDM, without an adverse effect on procedural parameters. Nevertheless, further research is needed to understand the underlying mechanism for increased recurrence rates after acute successful ablation.

Efficacy of Catheter Ablation for Atrial Arrhythmias in Patients with Arrhythmogenic Right Ventricular Cardiomyopathy-A Multicenter Study.

Background: Atrial arrhythmias are present in up to 20% of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). Catheter ablation (CA) is an effective treatment for atrial arrhythmias in the general population. Data regarding CA for atrial arrhythmias in ARVC are scarce. Objective: To assess the safety and efficacy of CA for atrial arrhythmias in patients with ARVC. Methods: In this international collaborative effort, all patients with a definite diagnosis of ARVC undergoing CA for atrial fibrillation (AF), focal atrial tachycardia (AT), or cavotricuspid isthmus (CTI)-dependent atrial flutter (AFl) were extracted from twelve ARVC registries. Demographic, periprocedural, and long-term arrhythmic outcome data were collected. Results: Thirty-seven patients were enrolled in the study (age 50.2 ± 16.6 years, male 84%, CHA2DS2VASc 1 (1,2), HAS-BLED 0 (0–2)). The arrhythmia leading to CA was AF in 23 (62%), focal left AT in 5 (14%), and CTI-dependent AFl in 9 (24%). Acute procedural success was achieved in all procedures but one (n = 1 focal left AT; 97% acute success). The median follow-up period was 27 (13–67) months, and 96%, 74%, and 61% of patients undergoing AF ablation were free from any atrial arrhythmia recurrence after a single procedure at 6 months, 12 months, and last follow-up, respectively. After focal AT ablation, freedom from atrial arrhythmia recurrence was 80%, 80%, and 60% at 6 months, 12 months, and last follow-up, respectively. All patients undergoing CTI ablation were free from atrial arrhythmia recurrences at 6 months, with 89% single-procedural arrhythmic freedom at last follow-up. One major complication (2.7%; PV stenosis requiring PV stenting) occurred. Conclusions: CA is safe and effective in managing atrial arrhythmias in patients with ARVC, with success rates comparable to the general population.

Radiofrequency catheter ablation of focal atrial tachycardia: characteristics and results of a series in a tertiary hospital

Abstract Funding Acknowledgements Type of funding sources: None. Background Focal atrial tachycardia (AT) is a relatively uncommon arrhythmia with poor response to medical treatment. Radiofrequency (RF) ablation appears to be a good option for treatment of symptomatic patients (P). Purpose To describe the clinical characteristics, electrophysiological (EP) findings, safety and short-term efficacy of catheter ablation in P with AT. Methods Retrospective analysis of consecutive P submitted to AT ablation using electroanatomical mapping between 2015 and 2020. If the AT was not present spontaneously, pacing maneuvers (atrial drive or burst pacing with up to 3 extra-stimuli) and isoprenaline was employed until reproducible induction of an ectopic atrial rhythm. Radiofrequency (RF) ablation was delivered at the site of earliest activation after validation of local electrograms until non-inducibility. Results A total of 46P (61% female) were included, with a mean age of 48 ± 23 years (minimum 8 months, maximum 86 years). Idiopathic AT was observed in 47,8%, while 52.2% had other relevant comorbidities (chronic pulmonary disease 17.4%; previous cardiac surgery 8,7%; congenital heart disease 10.9%; coronary artery disease 6.5%). Despite anti-arrhythmic therapy, daily palpitations were present in 87% of the cases and dizziness or syncope occurred in 22%). Nearly half (47.8%) had previously sought urgent medical care and 30.4% had a hospital admission due to arrhythmia. The clinical arrhythmia was documented in 34P (47.8% by 12-lead electrocardiography and 26.1% in 24h Holter monitoring). During the EP study a focal AT was documented in all P (spontaneously in 54.3% and induced with pacing maneuvers in 45.7%). AT origin after electroanatomical activation mapping is depicted in figure 1. After focal RF ablation, a second AT was induced in 16P (34.8%) and a new ablation was performed in 15 cases (93.8%). Total RF time was 508 ± 386 sec. One P developed right phrenic nerve palsy after ablation on the lateral wall of the right atrium. No other complications were noted. On follow-up (mean 320 ± 92 days), symptoms improved in 88.1% of the P, with a 3-fold decrease in urgent medical care visits and hospital admission for arrhythmia. Three P (8.7%) were submitted to a new EP study, in which an AT was documented and ablated in 2P. Conclusion AT is a very symptomatic arrhythmia, associated with increased usage of hospital resources and poor response to antiarrhythmic therapy. Ablation is an efficient treatment option, with a high success rate, low rate of complications and short-term clinical benefits. Abstract Figure. Distribution of focal atrial tachycardia

The characteristics and efficacy of catheter ablation of focal atrial tachycardia arising from an epicardial site.

BackgroundAlthough epicardial structures around the atrium such as adipose tissue possess arrhythmogenicity, little is known about atrial tachycardias (ATs) originating from epicardial sites (Epi‐ATs). This study aimed to elucidate the prevalence, characteristics, and outcome after radiofrequency catheter ablation (RFCA) of Epi‐ATs and to reveal the association between Epi‐ATs and the epicardial structures.MethodsThe electrocardiographic, electrophysiologic, and anatomical properties and results of RFCA were analyzed in 42 patients with a total of 49 ectopic ATs.ResultsSix Epi‐ATs (12%) were observed in six patients (14%). Four of six were respiratory cycle‐dependent ATs and one was a swallowing‐induced AT. The Epi‐AT origins were adjacent to a pulmonary vein (five cases) and vein of Marshall (one case). A Valsalva maneuver or atropine infusion to define the arrhythmia mechanism affected the appearance of the Epi‐ATs. The congruity rate between epicardial adipose tissue and the AT origin was significantly higher (100% vs. 44%, p = .045), and the epicardial adipose tissue volume of the atrium was significantly larger (104.1 vs. 64.6 ml, p = .04) in the Epi‐AT group. Endocardial RFCA targeting the AT foci resulted in acute success in five of five cases. However, electrical isolation including of the AT foci resulted in acute failures (two of three cases) or a recurrence (one of one case).ConclusionsSix Epi‐ATs were associated with thoracic veins and epicardial arrhythmogenic structures. The main cause provoking the Epi‐ATs was associated with autonomic nerve activity.

Catheter ablation of focal atrial tachycardia in children using three-dimensional electroanatomic mapping system: a 6-year single-centre experience.

This study demonstrates the clinical and electrophysiological details of catheter ablation conducted in children with focal atrial tachycardia using three-dimensional electroanatomic mapping systems. Electrophysiological procedures were performed using the EnSite™ system. Between 2014 and 2020, 60 children (median age 12.01 years [16 days-18 years]; median weight 41.5 kg [3-98 kg]) with focal atrial tachycardia and treated with catheter ablation were evaluated retrospectively. Tachycardia-induced cardiomyopathy was developed in 15 patients (25%). Most of the focal atrial tachycardia foci were right-sided (75%), and more than one focus was found in four patients. Radiofrequency ablation was performed in 47 patients (irrigated radiofrequency ablation in seven cases), cryoablation in 9, and radiofrequency ablation and cryoablation in the same session in 4 patients. The median procedural time was 163.5 minutes (82-473 minutes). Fluoroscopy was used in 29 of (48.3%) patients (especially for left-side substrate) with a mean time of 8.6±6.2 minutes. The acute success rate was 95%. The procedure failed in three patients, and recurrence was observed in 3.5% of patients (2/57) during a median follow-up of 17 months (2-69 months). The second ablation was performed in four cases, of which three were successful. Overall success rate was 96.6% with no major complications observed, except in one patient with minimal pericardial effusion. Catheter ablation seems to be an effective and safe treatment in focal atrial tachycardia. Electroanatomic mapping system can facilitate the ablation procedure and minimise radiation exposure.

Clinical characteristics and radiofrequency ablation of focal atrial tachycardia in 125 children

Objective: To investigate the clinical characteristics of focal atrial tachycardia (FAT) and the efficacy of radiofrequency catheter ablation (RFCA) in pediatric FAT. Methods: A total of 125 children with FAT who were treated with RFCA in the First Hospital of Tsinghua University from January 2010 to July 2018 were involved in the study. The clinical characteristics, origin of FAT, success rate of RFCA and recurrence rate and complications post RFCA were retrospectively analyzed, and the efficacy and X-ray radiation were compared between two-dimensional (2D) and 3D mapping system by t test or Chi-square analysis. Results: Among the 125 children, 57 were males and 68 females, age of (7.6±3.5) years old and body weight of (27.7±13.3) kg; and 62 (49.6%) had paroxysmal FAT, and 63 (50.4%) incessant FAT. Twenty-seven patients (21.6%) presented with tachycardia-induced cardiomyopathy (TIC), and 22 of whom (81.5%) were secondary to the incessant FATs. Most of the FATs originated from atrial auricle (46/125, 36.8%). Ablation was successful in 111 children (88.8%), and the recurrence rate was 25.2% (28/111). No complications were identified in the whole group. The efficacy and safety of 3D mapping system (87 cases) was better than that of the 2D mapping system (38 cases), according to the lower recurrence rate ((19.0% (15/79) vs. 40.6% (13/32), χ2 = 3.849, P=0.049), shorter X-ray exposure time ((4.9±2.3) vs. (12.5±5.7) min, t=7.942, P<0.01) and lower radiation doses ((5.3±3.3) vs. (10.9±3.7) mGy, t=8.038, P<0.01). Conclusions: FAT in children is mainly originated from atrial auricle, and incessant FAT is prone to progress to tachycardia-induced cardiomyopathy. RFCA is safe and effective for drug-resistant or drug-intolerant FAT in children, and 3D mapping system should be preferred.

Electrophysiological characteristics and therapeutic efficacy of radiofrequency ablation of focal atrial tachycardia originating from the right atrial appendage during pregnancy

Objective: To analyze the electrophysiological characteristics and the therapeutic efficacy of irrigated-tip catheter radiofrequency ablation(RFA) without radiation for pregnant women with focal atrial tachycardia(AT) originating from the right atrial appendage (RAA). Methods: Data from 55 women with focal AT, who underwent radiofrequency ablation (RFA) in the First Affiliated Hospital of Zhengzhou University from October 2016 to March 2019, were screened. 2 non-pregnant women with right atrial appendage tachycardia (RAAT) and 4 pregnant women with non-RAAT were excluded. The remaining 49 cases were divided into RAAT during pregnancy group (n=6, including 4 cases of tachycardia-induced cardiomyopathy) and non-pregnant and non-RAAT group (control, n=43). Under the guidance of three-dimensional mapping system, the earliest activation site was identified, RFA with the irrigated catheter without x-ray fluoroscopy was performed in RAAT patients during pregnancy, all patients in control group underwent non-zero-ray ablation. Patients were followed up at 3, 6, 12 months post procedure, and yearly follow up thereafter in outpatient clinic. Electrocardiogram or Holter monitoring was performed during follow up. AT recurrence and surgical complications were recorded during follow up. At 6 months after RFA, echocardiography examination and laboratory examination including N-terminal B-type brain natriuretic peptide measurement were performed in the pregnant patients, delivery results were also recorded in the pregnant patients. The electrophysiological characteristics of RAAT during pregnancy were analyzed, the therapeutic efficacy of RFA was compared between the two groups. Results: This study is a retrospective study. Age ((30.7±6.2)years vs. (57.2±11.7)years), left ventricular ejection fraction ((46.0±12.8)% vs. (60.1±5.9)%), proportions of organic heart disease (0% vs. 58%) were significantly lower in the RAAT patients during pregnancy group than in control group (P<0.05), while proportions of patients with persistent tachycardia (100% vs. 7%), symptoms of chest distress and palpitation (6/6 vs. 49%) and left ventricular ejection farction≤50% (4/6 vs. 9%) were significantly higher in RAAT group than in control group (P<0.05), heart rate was similar between the two groups ((163.7±11.1)beats/minutes vs. (153.7±15.2)beats/minutes, P>0.05). The characteristic P-wave morphology was observed in RAAT patients during pregnancy, i.e, P wave was mostly upright (5/6) in inferior-leads (Ⅱ, Ⅲ, aVF) and in lead I and aVL, deep and wide negative P wave was found in V1 lead (5/6), and gradually became positive from V2-V6. The mean tachycardia cycle length was (361.7±38.5) ms. Three-dimensional mapping showed that the origin points of the 6 RAAT pregnant patients were all scattered in the local region, the local region was ablated accordingly, 2 patients (2/6) received extensive ablation of local areas. Immediate successful rate was similar between the two groups (6/6 vs. 93%). During follow up ((15.3±4.0) months), no complications were observed after RFA, postoperative recurrence rate was similar (1/6 vs. 12%). Uncomplicated delivery was reported in all 6 pregnant RAAT post ablation. Normal cardiac structure and function was observed in the 4 pregnant patients with tachycardia-induced cardiomyopathy post ablation. Compared to pre-ablation phase, reduced left atrial dimension ((30.3±1.3) mm vs. (36.8±6.7) mm, P>0.05), increased left ventricular ejection fraction ((64.0±2.9)% vs. (39.8±10.7)%), reduced left ventricular end-diastolic dimension ((44.8±4.0) mm vs. (60.0±2.9) mm) and reduced N-terminal B-type natriuretic peptide value ((136.2±47.5) ng/L vs. (3 408.4±901.3) ng/L) were observed at 6 months post ablation (P<0.05). Conclusion: The electrophysiological characteristics are suggestive for focal AT originating from RAA during pregnancy. Under the guidance of 3-dimension activation mapping, no fluoroscopic RFA with irrigated-tip catheter is a safe and effective strategy for the treatment of focal RAAT during pregnancy.

Catheter ablation of supraventricular tachycardia

Supraventricular tachycardias (SVT) are common, with atrioventricular nodal reentry tachycardias (AVNRT) being the most common paroxysmal supraventricular tachycardia. The pathophysiological understanding and the catheter ablation of SVTs have developed steadily in recent years. For example, dividing AVNRT into "typical" and "atypical" depending on the HA-, VA-interval and AH/HA ratio is recommended. Because of higher rates of recurrences after cryoablation, radiofrequency ablation has prevailed in AVNRT. The current ESC guidelines for SVTs recommend the ablation of accessory pathways in asymptomatic high-risk patients and it is now aClassI recommendation. There is no recommendation for the access in left-sided accessory pathways. However, atransseptal compared to transaortic approach seems more promising in acute success. The use of athree-dimensional (3D) mapping system leads to areduction of the fluoroscopy times and procedure duration. Ablation of focal atrial tachycardia remains challenging despite the use of 3D electroanatomical mapping systems. However, new technologies such as high-density (HD) multipoint mapping systems can be helpful. HD mapping systems also allow abetter understanding of left and right atrial macroreentry tachycardia after previous ablation or cardiac surgery and in primary nature. However, in all technological advances, a proficient understanding of the basic techniques in electrophysiology, such as entrainment mapping, is mandatory.

Focal atrial tachycardia ablation: Highly successful with conventional mapping.

Radiofrequency catheter ablation (RFCA) of focal atrial tachycardia (FAT) traditionally is guided by conventional endocardial mapping of earliest atrial activation; however, more recently electro-anatomical mapping is heralded as a more effective, albeit more expensive, tool to guide ablation. Herein we present the results of conventional mapping-guided RFCA. Apropos, we conducted a literature search of studies reporting > 10 FAT patients submitted to RFCA. Conventional mapping-guided RFCA, performed in 63 FAT patients (aged 42.4+17.3years; 14 with incessant tachycardia and 12 with tachycardiomyopathy (TCM)), was successful in 61 (96.8%) patients, applied for single foci in 59 (93.7%) and two foci in 4 patients, right (n = 46) or left sided (n = 17). The earliest atrial activation time at the ablation site was 41.3 ± 16.2ms. Fluoroscopy time averaged 27.3+18.7min, and procedure lasted 2.6+1.7h. Complications occurred in two patients (sinus pauses in one needing a pacemaker and a large inguinal hematoma in one). Over 29.0+22.9months, four patients (6.5%) had recurrences, of whom three were successfully re-ablated. All patients with TCM showed gradual improvement to normalization over 4-6months. Literature search showed that RFCA success is equally high when guided with either conventional (88.5%) or electro-anatomical mapping (90%) with similar recurrences (9.6% vs. 9.5%). Conventional mapping-guided RFCA of FAT had high success (96.8%) with low complication (3.2%) and recurrence rates (6.5%). TCM was fully reversible. These results are comparable to those achieved with the more expensive electro-anatomical mapping, which may be reserved for more complex cases or for those failing the conventional approach.

Zero-fluoroscopy catheter ablation of focal atrial tachycardia in a pregnant woman with tachycardia induced cardiomyopathy

Introduction: Occurrence of tachycardias increase during pregnancy in line with the increased propensity to ectopic activity.Case presentation: We present a case of a 30-year-old woman in the 18th week of pregnancy with atrial tachycardia and tachycardia-induced cardiomyopathy that was successfully treated with zero fluoroscopy catheter ablation.Discussion: The described method is safe and efficient and could be used in the future when drug refractory tachycardias occur during pregnancy.

Acute and long-term outcome of focal atrial tachycardia ablation in the real world: results of the german ablation registry.

Catheter ablation of focal atrial tachycardia (FAT) can be a challenging procedure and results have been rarely described. The purpose of this study was to determine the characteristics and results of FAT ablation in the large cohort of the German Ablation Registry. The German Ablation Registry is a nationwide prospective multicenter database including 12566 patients who underwent an ablation procedure between 2007 and 2010. Among them 431 (3.4%) underwent an FAT ablation and 413 patients with documented locations were analyzed. Patients were divided into three groups according to the FAT location: biatrial (BiA, n = 31, 7.5%), left atrial (LA, n = 110, 26.5%), and right atrial (RA, n = 272, 66%). Acute success rate was 84% (68 vs. 85 vs. 85% in biA, LA, and RA, respectively, p = 0.038). 4.8% of patients had an early recurrence during hospitalization, most in biatrial location (p < 0.001). No major acute complication occurred. At 12months, 81% were asymptomatic or improved. The incidence of major adverse cardiovascular and cerebrovascular events (MACCE) was 3.7%. Arrhythmia freedom without antiarrhythmic drugs was 58% and was lower in biA (34 vs. 56% in LA vs. 62% in RA, p = 0.019). Early recurrence during hospitalization was an outstanding predictive factor for recurrence during follow-up. In this large patient population, FAT ablation had a relatively high acute success rate with a low complication rate. During follow-up, the recurrence rate was high, particularly in biatrial location. This was frequently predicted by an early recurrence during hospitalization.

Radiofrequency Ablation of Focal Atrial Tachycardia from Coronary Sinus

Focal atrial tachycardia (AT) is defined as atrial activation originating from a discrete focus with centrifugal spread. Available information suggests that focal activity can be caused by automaticity, triggered activity, or microreentry. Generally, AT response poorly to medication but can be treated by radiofrequency ablation with high long-term success. Focal AT represents approximately 3% to 17% of the patients referred for supraventricular tachycardia (SVT) radiofrequency ablation (RFA). Electrophysiology study is important to correctly diagnose the mechanism of the SVT before RFA is performed. Observation and several pacing maneuver could be done to identify the mechanism of SVT.A 54 year old female came with chief complaint of palpitation. During palpitation her ECG showed narrow complex regular tachycardia with the P-wave that was difficult to ascertain clearly. Electrophysiology study showed VA interval 130 ms, differences between VA interval during tachycardia and VA interval during RV pacing was 55 ms, no advanced in atrial activation, difference between ventricular post pacing interval (PPI) and tachycardia cycle length (TCL) was 130 ms, ventricular pacing during tachycardia results in V-A-A-V response before tachycardia resumes, and showed concentric atrial activation with earliest point at CS 9-10, indicating an AT from coronary sinus origin. AT was terminated during the RFA.Electrophysiology study is important to correctly diagnose AT, especially when P-wave during tachycardia in the surface ECG is uncertain. Several pacing maneuver during electrophysiology study can be very helpful to verify the diagnosis of AT.

PP-152 [AJC » Transcatheter ablation for tachyarrhythmias - Supraventricular tachycardia] Successful Radiofrequency Ablation Of Focal Atrial Tachycardia Arising From The Superior Mitral Annulus

PP-152 [AJC » Transcatheter ablation for tachyarrhythmias - Supraventricular tachycardia] Successful Radiofrequency Ablation Of Focal Atrial Tachycardia Arising From The Superior Mitral Annulus