Success Rate Of Catheter Ablation Research Articles

Electrophysiological characteristics of tachyarrhythmia and effects of catheter ablation in patients with Fontan circulation

Abstract Introduction Incidence of arrhythmia in complex congenital heart disease is higher than general population. Characteristics of arrhythmia in patients with functional single ventricle is not known. Methods Total 18 patients (age, 22.1 8.5 years, 9 men) with Fontan circulation who had undergone catheter ablation for tachyarrhythmia were retrospectively consecutively included. Characteristics of congenital heart disease, mechanisms of tachyarrhythmia, and efficacy and safety of catheter ablation were analyzed. Results Congenital heart diseases of the patients were as follows: double outlet right ventricle, 9; common atrioventricular septal defect, 5; and pulmonary atresia, 4. Fontan types were as follows: lateral tunnel Fontan, 9; extracardiac conduit Fontan 9. Fontan conduit puncture was successful in all patients. Mechanisms of tachyarrhythmia were as follows: intraatrial macroreentrant tachycardia, 8; focal atrial tachycardia, 4; atrioventricular nodal reentrant tachycardia, 3; twin atrioventricular nodal reciprocating tachycardia, 2; unknown, 2. Success rate of catheter ablation, recurrence rate, and complication rate were 16 of 18 patients, 2 of 18 patients, and 0 of 18 patients, respectively. Conclusion Intraatrial macroreentrant tachycardia is the most common tachycardia mechanism in patients with Fontan circulation. Catheter ablation for tachyarrhythmia is effective and safe in these population.

Usefulness of the systemic immune inflammation index to predict atrial fibrillation recurrence after cryoablation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Catheter-based atrial fibrillation (AF) ablation is an effective and reliable therapy in the treatment of patients with symptomatic and drug-refractory atrial fibrillation [1, 2]. Several factors and noninvasive clinical markers have been investigated to predict the success rate of catheter ablation[3, 4]. Inflammation is a well-established risk factor in the pathogenesis, initiation and perputuation of AF and in the recurrence of AF following ablation procedures [ 5]. The systemic immune inflammation index (SII) has emerged as a new predictor of inflammation and is determined using the following equation: neutrophil (N) × platelet (P) ÷ lymphocyte (L)[6]. The predictive value of this index on routine blood tests have been examined and suggested to be a powerful and independent prognostic factor of several cardiovascular diseases. [7, 8]. The current study sought to assess whether there is a relationship between SII level and recurrence of AF after catheter ablation. Methods This study was a single center and non-randomized study conducted at our city hospital Department of Cardiology. From January 2019 to March 2021 a total of 370 consecutive patients with symptomatic AF who underwent cryoablation were enrolled. The study population consisted of patients (mean age 56.1±12.3 years, 50.5% male) with drug-resistant symptomatic AF who underwent initial PV isolation with cryoballoon technique for documented AF. The patients were divided into two groups according to receurrence development Results After a mean follow-up period of 25.0±6.7 months, early recurrence was developed in 36 (9.7%) patients and recurrence after blanking period was observed in 77 patients (20.8%) patients. According to multivariate Cox proportional hazard regression analysis, pre-ablation SII level (HR: 2.32, 95% CI: 1.35–3.98, P: 0.002), left ventricular ejection fraction (HR: 0.96, 95% CI: 0.93–0.99, P : 0.020) and EHRA Score (HR: 2.04, 95% CI: 1.34–3.10, P : 0.001) were independent predictors of AF recurrence after cryoablation. In ROC curve analysis, using a cut-off level of 532, the pre-ablation SII level predicted AF recurrence with a sensitivity of 71.4% and a specificity of 67.9% (AUC: 0.88, 95% CI: 0.67–0.80; P <0.001) (Figure 1). In addition, correlation analysis revealed that there was a positive correlation of pre-procedural SII level with pre-procedural hsCRP level (r: 0.340, P <0.001). Figure 2 represent the Kaplan–Meier curves for the freedom from AF recurrence according to SII cut-off level of 532 (log-rank, P < 0.001). Conclusions Our findings revealed that, in patients with paroxysmal and/or persistent AF undergoing cryoablation, increased pre-ablation SII levels were associated with a higher rate of AF recurrence. As a readily available, low-cost and easy to access marker of inflammation, pre-ablation SII level has well-predicted AF recurrence after cryoballoon-based ablation.

PO-01-100 TEMPORAL TRENDS AND LESION SETS FOR PERSISTENT ATRIAL FIBRILLATION ABLATION – A META-ANALYSIS WITH TRIAL SEQUENTIAL ANALYSIS AND META-REGRESSION

Ablation for persistent atrial fibrillation (PsAF) has been performed for over 20 years though success rates have remained modest. Several adjunctive lesion sets have been studied but none have become standard of practice. Recent meta-analyses have suggested posterior wall isolation (PWI) is a beneficial lesion set in PsAF. In this study, we sought to describe how the efficacy of ablation for PsAF has evolved in the last two decades, with a focus on the effect of adjunctive ablation strategies. Databases were searched for prospective studies of PsAF ablation. We performed a systematic review with meta-regression and cumulative meta-analysis and trial sequential analysis (TSA). A total of 92 studies (12893 patients) were included. Ablation for PsAF achieved the primary outcome (freedom from AF/AT at 12 months follow-up) in 47.8% (CI 95% 43.4-52.1). Meta-regression showed freedom from AF/AT at 12 months has improved over time, while procedure time and fluoroscopy time have significantly reduced. TSA can be used to better control meta-analyses for type 1 and type 2 errors. TSA graphs are divided broadly into four zones, TSA area of benefit (green), TSA area of harm (red), area of futility (blue) and non-statistically significant zone (yellow) (Figure 1). The conventional boundaries (blue lines) indicate where conclusions of benefit or harm would be reached with traditional meta-analysis. In our analysis, TSA showed that complex fractionated atrial electrogram ablation is ineffective and further study of this treatment would be futile (Figure 1A). The last 3 randomized controlled trials (RCTs) were in fact were not required to reach this conclusion. PWI currently does not have sufficient evidence for routine use in PsAF ablation (Figure 1B). Importantly, prior to the recent CAPLA trial, meta-analysis without TSA would incorrectly conclude that PWI was beneficial. Overall success rates for catheter ablation of PsAF have increased steadily over time, with a reduction in procedure/fluoroscopy times. Through the use of TSA, we show the importance of adequately powered RCTs and meta-analyses prior to widespread adoption of novel therapies. This is particularly apparent for PWI, which despite recent promise and enthusiasm, does not currently have sufficient evidence to support its routine adoption, and requires further study.

Feasibility and safety of interventional electrophysiology and catheter ablation in the South African public sector: Challenges and opportunities for comprehensive cardiac electrophysiology in South Africa.

The spectrum and outcomes of catheter ablation procedures performed in South Africa are unknown, and therefore, the feasibility of interventional electrophysiology in the South African public sector is undetermined. This study was a retrospective review of all patients that underwent invasive electrophysiology procedures and catheter ablation at Groote Schuur Hospital (GSH) and the University of Cape Town Private Academic Hospital (UCTPAH) between 01 January 2013 and 31 December 2020.One thousand one hundred eighty-six invasive electrophysiology procedures were performed during the study period. Of these were 1102 catheter ablation procedures. There were 76 redo catheter ablation procedures, predominantly for atrial fibrillation (AF), which accounted for 39% (30/76) of the repeat procedures. There were only 0.8% (9/1102) catheter ablation related complications which were mostly access related. Atrial fibrillation accounted for most of the ablation procedures, 28.9% (318/1102); these were mainly performed at UCTPAH than at GSH, 300 vs 18 p< .0001. Cavotricuspid isthmus (CTI) dependent atrial flutter ablation was the second most commonly performed catheter ablation procedure, accounting for 21.6% (238/1102) of the catheter ablation procedures. More CTI dependent atrial flutter ablations were performed at GSH than a UCTPAH, 156 vs 82 p< .0001. The overall success rate of catheter ablation was 92%. A broad spectrum of catheter ablation procedures was performed with a high success rate and limited complications, thus demonstrating the feasibility of safe cardiac electrophysiology and catheter ablation in the South African public sector.

Left atrial appendage velocity as an instrument of predicting atrial fibrillation recurrence after successful catheter ablation – a useful tool?

Abstract Introduction Catheter ablation for the treatment of Atrial Fibrillation (AF) is a modality of treatment in growing expansion. However the sustained long term response in preventing AF recurrence is poor for most patients, namely in those with a dilated left atrium. Purpose Our aim was to assess the utility of an echocardiographic parameter for left atrium function, the left atrial appendage velocity (LAAV), in predicting recurrences after catheter ablation. Methods We performed a 9 year retrospective analysis of all patients who underwent a successful catheter ablation for the treatment of atrial fibrillation and had a valid pre-procedural transesophagic echocardiogram in a single expert centre. Medical records were analysed for demographic, procedural data and outcomes. Results Seventy-three (73) patients fulfilled all inclusion criteria and were analysed. The mean age was 62±11 with a male preponderance (58,7%). The majority of patients (82,7%) had preserved left ventricle ejection fraction. Only 46% of patient had a volumetric assessment of the left atrium dimensions prior to ablation, with slight, moderate and severe dilation of the left atrium in 20%; 8,6% and 28,6% of patients. Of the patients subjected to an AF ablation the average LAAV was 50,6±19 cm/s, with 78% of patients with normal atrial appendage velocities. Patients with low LAAV (&amp;lt;40cm/s) had a higher proportion of AF recurrences at 3 and 6 months (58,3 vs 12,8% and 89% vs 21,7%; p&amp;lt;0,05 for all) with a linear correlation between the presence of recurrences and LAAV (LAAV of 39,1 vs 57,5 cm/s; p&amp;lt;0,05 OR 0,91 (CI 95% = 0,85–0,97); r2=0,34 at 3 months and LAAV of 43,5 vs 59 cm/s; p=0,01; OR 0,94 (CI 95% = 0,89–0,99); r2=0,24 at 6 months respectively). There was a trend towards association with recurrences at 1 year although it did not reach statistical significance. There was no significant difference in the use of antiarritmic drugs, either prior or post ablation, in both groups. It was not possible to assess the additive predictive value to the left atrium dimensions due to the low percentage of volumetric assessment of left atrium prior to AF ablation. Conclusions Patients with low left atrial appendage velocities had a lower long term success rate of catheter ablation, with higher rates of recurrence at 3 and 6 months and a trend towards higher recurrences at 1 year, with linear correlation which hypothesises the use of the left atrial appendage velocity as novel predictive parameter for an integrative model. Funding Acknowledgement Type of funding sources: None.

Catheter ablation of long-standing persistent atrial fibrillation: the ugly type of AF?

Abstract Funding Acknowledgements Type of funding sources: None. Introduction In atrial fibrillation (AF) patients (pts), catheter ablation (CA) by isolating pulmonary veins (PVI) is the most effective therapeutic option in order to maintain sinus rhythm. The success rate of CA relies on type and duration of AF, being more successful in pts with paroxysmal AF and presenting suboptimal success in pts with long-standing persistent AF (LSPAF, &amp;gt;12 months). Purpose To evaluate the success of AF ablation, particularly in LSPAF. Methods Single-center prospective study of pts submitted to CA between 2004 and 2020. The strategy, regardless of the type of AF, was based on PVI, complemented by cavo-tricuspid isthmus line (CTI) in pts with history of flutter. Additional CA strategies were selectively considered in pts with stable atypical flutter conversion, persistent triggers or no electrograms in the VPs. Pts were monitored with Holter/7-day event loop recorder (3, 6, 12 months and annually up to 5 years). Success was assessed from the 90th day after ablation, with the absence of recurrences of any sustained atrial arrhythmias (&amp;gt; 30 sec). Cox regression and Kaplan-Meier survival were used to compare the success of ablation as a function of the clinical type of AF. Results 862 pts were submitted to AF ablation (67.3% male, mean age of 58 ± 0.41 years), including 130 pts (15.1%) with LSPAF, 63.3% with paroxysmal AF and 21.6% with short-duration persistent AF (SDPAF). In LSPAF, PVI was performed with irrigated catheter in 26.4%, PVAC in 39.5% and cryoablation in 34.1%. With a mean follow up period of 838 (IQ 159-1469) days, the 3-year success rate after a single procedure was 54.1% in LSPAF, compared to 72.4% in paroxysmal AF and 61.6% in SDPAF (LogRank - p &amp;lt; 0.0001 - figure 1). The risk of arrhythmic recurrence was 37% higher in patients with LSPAF comparing with other groups (HR 0.63 CI 95% 0.43-0.92, p 0.016). However after a mean of 1.17 procedures/patients, the success difference between groups was not detect (LogRank – p = 0.112 – figure 2). With additional ablation procedures (REDO), the success rate at 3 years was 82.9% LSPAF pts, compared 88.2% in paroxysmal AF pts and 83.6% in SDPAF pts. In LSPAF pts, different ablation techniques did not predict arrhythmic recurrence. Regarding comorbidities, higher prevalence of peripheral arterial disease (PAD, p = 0.005) a higher NT-proBNP (p = 0.006) and left auricular volume (p = 0.045) were associated with arrhythmic relapse. Conclusions AF ablation is more effective when performed earlier in the natural history of the disease. However, even in LSPAF pts, with additional procedures an acceptable rate of success can be achieve, independently from the ablation techniques. Abstract Figures 1 and 2: Success of AF ablation

A novel approach to mapping and ablation of septal outflow tract ventricular arrhythmias: Insights from multipolar intraseptal recordings

Catheter ablation is the preferred treatment option for idiopathic ventricular arrhythmias (VAs).1 Refinements in mapping and ablation technologies have led to a marked improvement in success rates of catheter ablation. Despite these improvements, VAs arising from specific anatomical locations such as the left ventricular summit (LVS) and the interventricular septum pose specific challenges to mapping and delivery of radiofrequency (RF) energy. A major obstacle in treating VAs from these sites is the inaccessibility of mapping from the endocardium or epicardium or the presence of intramural substrate that is challenging to record and target efficiently with standard techniques.

Efficacy of LGE-MRI-guided fibrosis ablation versus conventional catheter ablation of atrial fibrillation: The DECAAF II trial: Study design.

Success rates of catheter ablation in persistent atrial fibrillation (AF) remain suboptimal. A better and more targeted ablation strategy is urgently needed to optimize outcomes of AF treatment. We sought to assess the safety and efficacy of targeting atrial fibrosis during ablation of persistent AF patients in improving procedural outcomes. The DECAAF II trial (ClinicalTrials. gov identifier number NCT02529319) is a prospective, randomized, multicenter trial of patients with persistent AF. Patients with persistent AF undergoing a first-time ablation procedure were randomized in a 1:1 fashion to receive conventional pulmonary vein isolation (PVI) ablation (Group 1) or PVI + fibrosis-guided ablation (Group 2). Left atrial fibrosis and ablation induced scarring were defined by late gadolinium enhancement magnetic resonance imaging at baseline and at 3-12 months postablation, respectively. The primary endpoint is the recurrence of atrial arrhythmia postablation, including atrial fibrillation, atrial flutter, or atrial tachycardia after the 90-day postablation blanking period. Patients were followed for a period of 12-18 months with a smartphone ECG Device (ECG Check Device, Cardiac Designs Inc.). With an anticipated enrollment of 900 patients, this study has an 80% power to detect a 26% reduction in the hazard ratio of the primary endpoint. The DECAAF II trial is the first prospective, randomized, multicenter trial of patients with persistent AF using imaging defined atrial fibrosis as a treatment target. The trial will help define an optimal approach to catheter ablation of persistent AF, further our understanding of influencers of ablation lesion formation, and refine selection criteria for ablation based on atrial myopathy burden.

Sleep Apnea and Atrial Fibrillation

Obstructive sleep apnea (OSA) creates a complex and dynamic substrate for atrial fibrillation (AF), which is characterized by structural remodeling as a result of long-term OSA as well as transient and acute apnea-associated transient atrial electrophysiological changes. OSA is present in 21% to 74% of patients with AF, and nonrandomized studies suggest that treatment of OSA by continuous positive airway pressure may help to maintain sinus rhythm after electrical cardioversion and improve catheter ablation success rates. Management of OSA in patients with AF requires a close interdisciplinary collaboration between the electrophysiologist/cardiologist and sleep specialists.

Radiofrequency Ablation Strategies for Intramural Ventricular Arrhythmias.

Catheter ablation is an established treatment strategy for ventricular arrhythmias. However, the presence of intramural substrate poses challenges with mapping and delivery of radiofrequency energy, limiting overall success of catheter ablation. Advances over the past decade have improved our understanding of intramural substrate and paved the way for innovative treatment approaches. Modifications in catheter ablation techniques and development of novel ablation technologies have led to improved clinical outcomes for patients with ventricular arrhythmias. In this review, we explore mapping techniques to identify intramural substrate and describe available radiofrequency energy delivery techniques that can improve overall success rates of catheter ablation.

Unsupervised Classification of Atrial Fibrillation Triggers Using Heart Rate Variability Features Extracted from Implantable Cardiac Monitor Data.

Catheter ablation is a common treatment of atrial fibrillation (AF), but its success rate is around 60%. It is believed that the success rate can be improved if the procedure were to be guided by the specific AF triggers found in the "Flashback", i.e. the trend of around 500 ventricular beats preceding the AF onset stored in an implantable cardiac monitor (ICM). The need to automatically classify these different triggers: atrial tachycardia (AT), atrial flutter, premature atrial contractions (PAC) or Spontaneous AF has motivated the design in this paper of an unsupervised classification method evaluating statistical and geometrical Heart Rate Variability (HRV) features extracted from the Flashback. From a cohort of 132 patients (57± 12 years, male 67%), 528 Flashbacks were extracted and classified into 5 different clusters after the Principal Component Analysis (PCA) was computed on the HRV features. 2 principal components explained more than 95% of the variance and were a combination of the mean R-R interval, Square root of the mean squared differences of successive R-R intervals (RMSSD), Standard deviation of the R-R intervals (SDNN) and Poincare descriptors, SD1 and SD2. RMSSD and SD1 were significantly different among all clusters (p-value < 0.05, with Holm's correction) showing that distinct patterns can be found using this method.Clinical Relevance-Preliminary step towards ablation strategy guidance using the AF trigger patterns to improve catheter ablation success rates.

Long-term Outcome of Pulmonary Vein Isolation Versus Amiodarone Therapy in Patients with Coexistent Persistent AF and Congestive Heart Failure.

Although pharmacological rhythm control of AF in patients with heart failure with reduced ejection fraction (HFrEF) does not seem to provide any benefit over rate control, catheter ablation of AF has been shown to improve clinical outcomes. These results can be explained with higher success rates of catheter ablation in restoring and maintaining sinus rhythm compared with antiarrhythmic drugs. In addition, pharmacotherapy is not void of side-effects, which are thought to offset its potential antiarrhythmic benefits. Therefore, efforts should be made towards optimisation of ablation techniques for AF in patients with HFrEF.

LONG-TERM ABLATION OUTCOME IN PATIENTS WITH COEXISTENT DIABETES AND ATRIAL FIBRILLATION TREATED WITH INSULIN, ORAL ANTIDIABETIC AGENTS OR LIFE-STYLE CHANGE FOR GLYCAEMIA-CONTROL

We evaluated success rate of catheter ablation in AF patients with coexistent diabetes treated with insulin or oral hypoglycemic agents or life-style change. A total of 800 consecutive AF patients with documented diagnosis of diabetes undergoing catheter ablation were classified into 3 groups based

Catheter Ablation of Atrial Fibrillation: State of the Art and Future Perspectives.

Purpose of ReviewAtrial fibrillation (AF), the most common sustained arrhythmia, is associated with high rates of morbidity and mortality. Maintenance of stable sinus rhythm (SR) is the intended treatment target in symptomatic patients, and catheter ablation aimed at isolating the pulmonary veins provides the most effective treatment option, supported by encouraging clinical outcome data. A variety of energy sources and devices have been developed and evaluated. In this review, we summarize the current state of the art of catheter ablation of AF and describe future perspectives.Recent FindingsCatheter ablation is a well-established treatment option for patients with symptomatic AF and is more successful at maintaining SR than antiarrhythmic drugs. Antral pulmonary vein isolation (PVI) as a stand-alone ablation strategy results in beneficial clinical outcomes and is therefore recommended as first-line strategy for both paroxysmal and persistent AF. While radiofrequency-based PVI in conjunction with a three-dimensional mapping system was for many years considered to be the “gold standard”, the cryoballoon has emerged as the most commonly used alternative AF ablation tool, especially in patients with paroxysmal AF. Patients with persistent or long-standing persistent AF and with arrhythmia recurrence after previous PVI may benefit from additional ablation strategies, such as substrate modification of various forms or left atrial appendage isolation. New technologies and techniques, such as identification of the AF sources and magnetic resonance imaging-guided substrate modification, are on the way to further improve the success rates of catheter ablation for selected patients and might help to further reduce arrhythmia recurrence.ConclusionsPulmonary vein isolation is the treatment of choice for symptomatic patients with paroxysmal and persistent drug-refractory AF. The reconnection of previously isolated pulmonary veins remains the major cause of AF recurrence. Novel ablation tools, such as balloon technologies or alternative energy sources, might help to overcome this limitation. Patients with non-paroxysmal AF and with AF recurrence might benefit from alternative ablation strategies. However, further studies are warranted to further improve our knowledge of the underlying mechanisms of AF and to obtain long-term clinical outcomes on new ablation techniques.

"If at first you don't succeed": repeat ablations in young patients with supraventricular tachycardia.

Success rates for catheter ablation of supraventricular tachycardia (SVT) in the young exceed 90%. While studies have described reasons for initial ablation failure, less is known about outcomes of repeat ablation attempts. The purpose of this study was to report acute and mid-term success rates for second ablation attempts in young patients, as well as to analyze factors that may affect these outcomes. Retrospective single-center study of all patients undergoing a second ablation attempt for WPW (Wolff-Parkinson-White) or SVT from 2008 to 2017. Inclusion criteria are all patients < 21years old at the time of their first ablation who underwent a second ablation attempt. An intention to treat analysis was performed. Fifty-five patients met inclusion criteria, with a median age of 15years (IQR 12-16). The most common arrhythmia mechanisms at repeat procedure were single accessory pathways (n = 32, 58%) and AVNRT (n = 14, 25%). Six patients (11%) were found to have a different SVT mechanism than at initial ablation. Acute success at repeat ablation was achieved in 48 patients (87%). At mid-term follow-up (10.5months, IQR 0.6-25), four patients (8% of acute successes) experienced SVT recurrence. The overall success rate of repeat ablations, accounting for acute and mid-term failures, was 80%. In this report of 55 young patients who underwent repeat ablation for WPW and/or SVT, acute and mid-term success rates were 87% and 80%, respectively. These data may help inform decision-making when caring for patients with persistent or recurrent SVT after an initial ablation attempt.

Catheter ablation of ventricular tachycardia in the pediatric patients: A single-center experience.

Ventricular tachycardia (VT) with or without structural heart disease is uncommon but well-recognized clinically in children. With this retrospective study, we collected the data from the in-hospital pediatric patients of VT with catheter ablation therapy. The purpose of this study is to assess the acute results and the long-term outcome of catheter ablation in pediatric patients of VT in our single pediatric center. This study included 53 consecutive children (male/female=33/20, mean age=8.2±3.4 years, mean bodyweight=32.6±13.7kg). All patients underwent electrophysiological study with an attempt of catheter ablation for clinical monomorphic VT. Acute and long-term success rate of catheter ablation for the treatment of VT were compared between right and left VT as well as fascicular VT (FVT) and nonfascicular VT. There were 53 idiopathic VT forms found in the children, including FVT (n=32), outflow tract VT (n=15), papillary muscle VT (n=5), and bundle branch reentry VT (n=1). Acute success of catheter ablations for VT was achieved in 57 of all the 59 ablation procedures (97%) with VT recurrence occurred in six of 53 patients (11%). During a mean follow-up period of 29.2±21.7 months (range 1-76 months) after hospital discharge, ablations in nonfascicular VT were as successful as FVT. There was no significant difference in the success rate between the right and left VT. Catheter ablation is an effective treatment for idiopathic VT in children. The acute and long-term success rates of catheter ablation for idiopathic VT in pediatric patients with normal heart structure are satisfying.

Catheter ablation of ventricular arrhythmias originating from the para-Hisian region with reversed C-curve technique.

Ventricular arrhythmias (VAs) originating from the para-Hisian region represent a challenging location. The long-term success rate of catheter ablation above the septal leaflet of the tricuspid valve is not ideal. This study aimed to investigate the safety and efficacy of catheter ablation for para-Hisian VAs via a direct approach under the septal valve with reversed C-curve technique. Twenty-five consecutive patients with para-Hisian VAs were included. Systematic mapping was performed in the right ventricle septum, including both the regions above and under the septal valve. Radiofrequency (RF) ablation was preferentially performed under the valve with reversed C-curve technique in all patients. If the ablation failed under the valve, it was then performed above the valve and even in aortic sinus cusps. The earliest ventricular activation preceding surface QRS (V-QRS) under the valve was significantly larger than that above the valve (34.8 ± 5.3 vs 27.8 ± 5.7 ms, P < .01). RF ablation under the valve with reversed C-curve technique achieved acute success in 22 of 25 (88%) patients. Junctional rhythm developed during ablation in 3 of 25 (12%) patients and no atrioventricular block occurred. In the remaining three patients, RF application above the valve failed to eliminate the VAs and one of them achieved successful ablation in the right coronary cusp. During a mean follow-up of 17.8 ± 9.4 months, no patients presented with VAs recurrence and no postprocedure complications occurred. Catheter ablation under the valve with reversed C-curve technique shows to be effective and safe for para-Hisian VAs.

Association between left atrial reverse remodeling and maintenance of sinus rhythm after catheter ablation of persistent atrial fibrillation

The success rate of catheter ablation of persistent atrial fibrillation (AF) is not satisfactory, for reasons that are unclear. The purpose of this study was to examine the relationship between left atrial reverse remodeling after ablation and recurrence of AF in patients with persistent AF. One hundred and thirty-two patients with persistent AF were enrolled. Extensive encircling pulmonary vein isolation plus ablation of complex fractionated atrial electrograms was performed. Bepridil or amiodarone was prescribed for 3 months after ablation. All patients were studied by serial echocardiography and 24-h ambulatory electrocardiogram at baseline, for the day after ablation, and at 1-, 3-, and 6-month intervals after ablation. Recurrence of AF was observed in 42 patients at 2-year follow-up. The duration of AF (median 12 (IQR 6–37) vs 8 (IQR 5–17) months, p < 0.05), and early recurrence of AF (69 vs 26%, p < 0.05) after ablation were significantly different between the patients with AF recurrence and those without. The left atrial dimensions at 3 months (40 ± 6 vs 44 ± 6 mm, p < 0.001) and 6 months (40 ± 6 vs 44 ± 6 mm, p < 0.001) were significantly smaller than those just after ablation in the patients without AF recurrence. A 5% reduction from baseline in the left atrial dimension at 6 months after ablation was associated with freedom from late AF recurrence (p < 0.05). Left atrial reverse remodeling after ablation of persistent AF was associated with freedom from late recurrence of AF.

Current Concepts of Anatomy, Electrophysiology, and Therapeutic Implications of the Interatrial Septum

The interatrial septum (IAS), a fibromuscular structure separating the right (RA) and left (LA) atrium, plays an important role in both intra- and interatrial conduction. Electropathological changes in the IAS such as discordant activation of theright and left septal layer and conduction disorders may facilitate intraseptal re-entry and promote development of atrial tachyarrhythmias such as atrial fibrillation (AF). Various experimental studies have emphasized the importance ofthe IAS in AF initiation and perpetuation. Moreover, a thicker IAS has been associated with atrial tachyarrhythmias anda lower success rate of catheter ablation. Therefore, it is assumed that the septal interatrial connections, which may be more pronounced in patients with a thicker IAS, may furnish an anatomic pathway for re-entry and may explain failureof catheter ablation therapy. However, the exact role of the IAS in the treatment of AF still remains an enigma. Moreprofound understanding of the role of the IAS in the pathophysiology of AF and other atrial tachyarrhythmias isnecessary to improve success of current therapeutic options and develop new treatment modalities. This review outlines the current knowledge on the relationship between anatomic and electrophysiological properties of theIASanddiscusses its involvement in atrial tachyarrhythmias.

ПРОГНОЗИРОВАНИЕ РЕЦИДИВА ФИБРИЛЛЯЦИИ ПРЕДСЕРДИЙ У ПАЦИЕНТОВ С ПЕРСИСТИРУЮЩЕЙ ФОРМОЙ АРИТМИИ, СТРАДАЮЩИХ СИНДРОМОМ ОБСТРУКТИВНОГО АПНОЭ/ГИПОПНОЭ СНА

Background. Untreated obstructive sleep apnoea-hypopnoea syndrome (OSAHS) in atrial fibrillation (AF) patients influences the efficacy of antiarrhythmic drug therapy and reduces electrical cardioversion and catheter ablation success rates. The aim: to elaborate a predictive model, which will help to identify high-risk patients with AF recurrence during the first year after electrical cardioversion in patients with non-valvular persistent AF, suffering from OSAHS. Material and methods. We examined 46 non-valvular persistent AF patients, undergoing electrical cardioversion; mean age 57,2±6,4 year. All patients were subjected to cardiorespiratory monitoring. The AF recurrence data were obtained on the study patients during one year following cardioversion. Statistical analysis was performed using STATISTICA 10.0 (StatSoft, Inc., USA) and programm «RStudio 1.1.183». Results. A predictive model, which will help to identify high-risk patients with AF recurrence during the first year after electrical cardioversion in patients with non-valvular persistent AF, suffering from OSAHS, was elaborated (sensitivity 82,76 , specificity 82,35%). Conclusion. The use of the statistical model will enable more carefully to predict the recurrence of AF in patients with non-valvular persistent AF, suffering from OSAHS, and to perfom appropriate management of such patients.