Long-term outcomes of the pentaspline pulsed-field ablation catheter for the treatment of paroxysmal atrial fibrillation: results of the prospective, multicentre FARA-Freedom Study.

AIMS: Pulmonary vein isolation (PVI) is a well-established strategy for the treatment of paroxysmal atrial fibrillation (PAF). Despite randomized controlled trials and real-world data showing the promise of pulsed-field ablation (PFA) for this treatment, long-term efficacy and safety data demonstrating single-procedure outcomes off antiarrhythmic drugs remain limited. The aim of the FARA-Freedom Study was to evaluate the long-term efficacy and safety of PFA using the pentaspline catheter for PAF. METHODS AND RESULTS: FARA-Freedom, a prospective, non-randomized, multicentre study, enrolled patients with PAF undergoing de novo PVI with PFA, who were followed for 12 months with weekly transtelephonic monitoring and a 72-h Holter ECG at 6 and 12 months. The primary safety endpoint was a composite of device- or procedure-related serious adverse events out to 7 days post-ablation and PV stenosis or atrioesophageal (AE) fistula out to 12 months. Treatment success is a composite of acute PVI and chronic success, which includes freedom from any documented atrial tachyarrhythmia longer than 30 s, use of antiarrhythmic drugs or cardioversion after a 3-month blanking period, or use of amiodarone or repeat ablation at any time. The study enrolled 179 PAF patients (62 ± 10 years, 39% female) at 13 centres. At the index procedure, all PVs were successfully isolated with the pentaspline PFA catheter. Procedure and left atrial dwell times, with a 20-min waiting period, were 71.9 ± 17.6 and 41.0 ± 13.3 min, respectively. Fluoroscopy time was 11.5 ± 7.4 min. Notably, monitoring compliance was high, with 88.4 and 90.3% with weekly events and 72-h Holter monitors, respectively. Freedom from the composite primary effectiveness endpoint was 66.6%, and 41 patients had atrial tachyarrhythmia recurrence, mostly recurrent atrial fibrillation (31 patients). The composite safety endpoint occurred in two patients (1.1%), one tamponade and one transient ischaemic attack. There was no coronary spasm, PV stenosis, or AE fistula. There were four cases of transient phrenic nerve palsy, but all resolved during the index procedure. CONCLUSION: In this prospective, non-randomized, multicentre study, PVI using a pentaspline PFA catheter was effective in treating PAF patients despite rigourous endpoint definitions and high monitoring compliance and demonstrated favourable safety. REGISTRATION: Clinical Trials.gov Identifier: NCT05072964 (sponsor: Boston Scientific Corporation).

Telemedicine in arrhythmology.

Telemedicine can be defined as a health care service that, specifically in the field of diagnostics, employs remote transfer of a large volume of data from a large number of subjects at the same time. This data is subsequently processed on a central basis and returned to a large number of health care providers by whom the service was ordered on national or international level. In arrhythmology, telemedicine is used particularly in long-term ECG monitoring to diagnose arrhythmias and check out treatment outcome via external recorders, smart watch, and implantable devices. To facilitate analysis of large telemedicine data volume, artificial intelligence is being increasingly exploited.

Stereotactic radiosurgery for ablation of ventricular tachycardia.

AIMS: Stereotactic body radiotherapy (SBRT) for ventricular tachycardias (VTs) could be an option after failed catheter ablation. In this study, we analysed the long-term efficacy and toxicity of SBRT applied as a bail-out procedure. METHODS AND RESULTS: Patients with structural heart disease and unsuccessful catheter ablations for VTs underwent SBRT. The planning target volume (PTV) was accurately delineated using exported 3D electroanatomical maps with the delineated critical part of re-entry circuits. This was defined by detailed electroanatomic mapping and by pacing manoeuvres during the procedure. Using the implantable cardioverter-defibrillator lead as a surrogate contrast marker for respiratory movement compensation, 25 Gy was delivered to the PTV using CyberKnife. We evaluated occurrences of sustained VT, electrical storm, antitachycardia pacing, and shock; time to death; and radiation-induced events. From 2014 until March 2017, 10 patients underwent radiosurgical ablation (mean PTV, 22.15 mL; treatment duration, 68 min). After radiosurgery, four patients experienced nausea and one patient presented gradual progression of mitral regurgitation. During the follow-up (median 28 months), VT burden was reduced by 87.5% compared with baseline (P = 0.012) and three patients suffered non-arrhythmic deaths. After the blanking period, VT recurred in eight of 10 patients. The mean time to first antitachycardia pacing and shock were 6.5 and 21 months, respectively. CONCLUSION: Stereotactic body radiotherapy appears to show long-term safety and effectiveness for VT ablation in structural heart disease inaccessible to catheter ablation. We report one possible radiation-related toxicity and promising overall survival, warranting evaluation in a prospective multicentre clinical trial.

Functional improvement after successful catheter ablation for long-standing persistent atrial fibrillation.

AIMS: Identifying patients who benefit from restored sinus rhythm (SR) would optimize the selection of candidates for ablation of long-standing persistent atrial fibrillation (LSPAF). This prospective study sought to identify the hitherto unknown factors associated with global functional improvement after successful radiofrequency catheter ablation of LSPAF. METHODS AND RESULTS: In 171 LSPAF patients (84% of the total consecutive 203 patients) who were examined in SR 12 months after ablation, the individual per cent change from baseline value in maximum oxygen consumption at exercise test (VO2 max), left ventricular ejection fraction (LVEF), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and five-dimensional descriptive system (EQ-5D) of quality-of-life questionnaire were classified in quartiles by 0 (worse) to 3 (best) grades. The individual grades were summed into a composite score (SCORE, 0 … 12) reflecting global functional improvement. Significant improvement in VO2 max (3.4 ± 4.7 mL/kg/min), LVEF (7.5 ± 9.1%), NT-proBNP (-861 ± 809 pg/mL), and EQ-5D (0.7 ± 0.12) was observed (all P < 0.0001). On multivariable analysis, younger age (P = 0.001), male gender (P = 0.02), timely post-ablation left atrial appendage (LAA) outflow (P = 0.005) with improvement in outflow velocity (P = 0.0002), and withdrawal of Class I/III antiarrhythmic drugs (P < 0.05) were positively and independently correlated with the SCORE. CONCLUSIONS: Younger male patients benefited most from catheter ablation of LSPAF. Delayed or non-improved LAA outflow and inability to discontinue Class I/III antiarrhythmic medication reduced the post-ablation functional improvement.

Catheter ablation of atrial fibrillation in patients with diabetes mellitus: a systematic review and meta-analysis.

AIMS: Diabetes mellitus (DM) and atrial fibrillation (AF) share pathophysiological links, as supported by the high prevalence of AF within DM patients. Catheter ablation of AF (AFCA) is an established therapeutic option for rhythm control in drug resistant symptomatic patients. Its efficacy and safety among patients with DM is based on small populations, and long-term outcome is unknown. The present systematic review and meta-analysis aims to assess safety and long-term outcome of AFCA in DM patients, focusing on predictors of recurrence. METHODS AND RESULTS: A systematic review was conducted in MEDLINE/PubMed and Cochrane Library. Randomized controlled trials, clinical trials, and observational studies including patients with DM undergoing AFCA were screened and included if matching inclusion and exclusion criteria. Fifteen studies were included, adding up to 1464 patients. Mean follow-up was 27 (20-33) months. Overall complication rate was 3.5 (1.5-5.0)%. Efficacy in maintaining sinus rhythm at follow-up end was 66 (58-73)%. Meta-regression analysis revealed that advanced age (P < 0.001), higher body mass index (P < 0.001), and higher basal glycated haemoglobin level (P < 0.001) related to higher incidence of arrhythmic recurrences. Performing AFCA lead to a reduction of patients requiring treatment with antiarrhythmic drugs (AADs) from 55 (46-74)% at baseline to 29 (17-41)% (P < 0.001) at follow-up end. CONCLUSIONS: Catheter ablation of AF safety and efficacy in DM patients is similar to general population, especially when performed in younger patients with satisfactory glycemic control. Catheter ablation of AF reduces the amount of patients requiring AADs, an additional benefit in this population commonly exposed to adverse effects of AF pharmacological treatments.

Expression, characterization and homology modeling of a novel eukaryotic GH84 ß-N-acetylglucosaminidase from Penicillium chrysogenum.

ß-N-acetylglucosaminidases from the family 84 of glycoside hydrolases form a small group of glycosidases in eukaryotes responsible for the modification of nuclear and cytosolic proteins with O-GlcNAc, thus they are involved in a number of important cell processes. Here, the first fungal ß-N-acetylglucosaminidase from Penicillium chrysogenum was expressed in Pichia pastoris and secreted into the media, purified and characterized. Moreover, homology modeling and substrate and inhibitor docking were performed to obtain structural information on this new member of the GH84 family. Surprisingly, we found that this fungal ß-N-acetylglucosaminidase with its sequence and structure perfectly fitting to the GH84 family displays biochemical properties rather resembling the ß-N-acetylhexosaminidases from the family 20 of glycoside hydrolases. This work helped to increase the knowledge on the scarcely studied glycosidase family and revealed a new type of eukaryotic ß-N-acetylglucosaminidase.

Long-term results of paediatric radiofrequency catheter ablation: a population-based study.

AIMS: We aimed to evaluate long-term utilization and results of paediatric radiofrequency catheter ablation (RFCA) in a population-based study. METHODS AND RESULTS: Data from all three centres performing paediatric RFCA for the whole population of the Czech Republic between 1993 and 2010 were retrospectively reviewed. A total of 708 ablation procedures in 633 consecutive patients <18 years for 716 different substrates were tracked, with accessory pathways = 439 (61.3%) and atrioventricular nodal reentry tachycardia (AVNRT) = 205 (28.6%) being most frequent. Incidence of RFCA reached 0.049 per 1000 children <18 years of age in the recent era (2006-10). Indications included patient preference (68.0%), drug refractoriness (15.5%), asymptomatic Wolff-Parkinson-White pre-excitation (8.4%), and malignant arrhythmia (6.1%). Median follow-up was 13.7 (interquartile range 5.7-21.5) months. Overall acute/long-term success of the primary procedure was 89.1/77.2% (accessory pathways 87.2/77.7%, AVNRT 98.5/84.4%). Re-ablation was performed in 73 of 163 substrates after a primary unsuccessful ablation resulting in a long-term cumulative efficacy of 96.3%. Between 1993-2005 and 2006-10, procedure/fluoroscopy time decreased from median 154/24 to 105/14 min. (P < 0.001 for both). Serious complications occurred in nine patients (1.4%). CONCLUSION: This population-based study could replicate data from previous single- or multi-centre reports confirming RFCA as a safe method of arrhythmia treatment in children with long-term cumulative efficacy exceeding 90% and significant decrease in the procedure and fluoroscopy time during the study period. The need for RFCA can be estimated at ∼0.05/1000 children <18 years using current indication criteria.

A prospective evaluation of haemodynamics, functional status, and quality of life after radiofrequency catheter ablation of long-standing persistent atrial fibrillation.

AIMS: Clinical benefit from ablation for long-standing persistent atrial fibrillation has remained unknown. We hypothesized that successful ablation of long-standing persistent atrial fibrillation would improve haemodynamics, functional status, and quality of life. METHODS AND RESULTS: A total of 160 patients (aged 59 ± 9 years, 23% females) undergoing ablation of long-standing (median of 28 months) persistent atrial were enrolled in this prospective study. Morphological and functional echocardiographic parameters, N-terminal prohormone of brain natriuretic peptide (NT-proBNP), maximum oxygen consumption during exercise test (VO2 max), and quality of life were assessed at baseline and 1 year after the ablation.  At the 1-year follow-up visit, 81% patients were examined in sinus rhythm (after repeat ablation in 38% patients). Left atrial appendage outflow velocity increased from 44 ± 20 to 58 ± 23 cm/s, left ventricular ejection fraction from 54 ± 9 to 59 ± 5%, and VO2 max from 20.4 ± 6.4 to 23.7 ± 8.1 mL/kg/min; NT-proBNP decreased from median 897 (interquartile range 603-1424) to 230 (interquartile range 120-420) pg/mL (all P < 0.0001). These beneficial effects of ablation were predominantly associated with the presence of sinus rhythm. Quality of life (range 0-100) increased significantly (EQ-5D index: from 68.8 ± 12.5 to 75.4 ± 14.4; EQ-VAS score: from 62.8 ± 13.2 to 70.6 ± 13.8; both P < 0.0001). CONCLUSION: Ablation of long-standing persistent atrial fibrillation was associated with significant recovery of haemodynamics and exercise capacity that projected onto the long-term improvement in quality of life.

Early ganglion stellate blockade as part of two-step treatment algorithm suppresses electrical storm and need for intubation.

BACKGROUND: For the treatment of patients with electrical storm (ES), we established a two-step algorithm comprising standard anti-arrhythmic measures and early ultrasound-guided stellate ganglion blockade (SGB). In this single-center study, we evaluated the short-term efficacy of the algorithm and tested the hypothesis that early SGB might prevent the need for intubations. METHODS: Overall, we analyzed data for 70 ES events in 59 patients requiring SGB (mean age 67.7 ± 12.4 years, 80% males, left ventricular ejection fraction 30.0% ± 9.1%), all with implantable cardioverter-defibrillators (ICDs). RESULTS: The mean time from ES onset to SGB was 13.2 ± 12.3 hours. Percentage and mean absolute reduction in shocks at 48 hours after SGB reached 86.8% (-6.3 shocks), and anti-tachycardiac pacing (ATP) declined by 65.9% (-51.1 ATPs; all P < 0.001). Patients with the highest sustained ventricular arrhythmia (VA) burden (shocks ≥10/48 h; ATPs 10-99/48 h and ≥100/48 h) experienced the highest percentage decrease in ICD therapy (shocks -99.1%; ATPs -92.1% and -100.0%, respectively). For clinical response by defined criteria and two outcome periods (1/no sustained VA ≤48 hours post SGB, and 2/no ICD shock or <3 ATPs/day from day 3 to discharge/catheter ablation/day 8), 75.7% and 76.1% experienced complete response, respectively. Catecholamine support, no/low-dose ß-blocker therapy, polymorphic/mixed-type VA, and baseline sinus rhythm versus atrial fibrillation were more frequent in patients with early arrhythmia recurrence. Temporary Horner's syndrome occurred in 67.1%, and no other adverse events were recorded. Intubation and general anesthesia during and after SGB were not needed. CONCLUSION: The presented two-step algorithm for treating ES proved efficacious and safe. The results support implementation of early SGB in routine ES management.

Sequencing, cloning and high-yield expression of a fungal ß-N-acetylhexosaminidase in Pichia pastoris.

The ß-N-acetylhexosaminidase from Talaromyces flavus has a remarkable synthetic ability, processing even carbohydrates with various functionalities. Its broader use is partially hampered by low-yield production in the native fungus. Here, we present an optimized 3-day production of this enzyme in the eukaryotic host of Pichia pastoris, in ca 10-fold higher volume activity (10 U/ml) and close-to-perfect purity (one chromatographic step needed). Importantly, the recombinant enzyme features the same biochemical and catalytic properties, including the syntheses with derivatized carbohydrate substrates. This is the first example of the overexpression of a fungal ß-N-acetylhexosaminidase by a single-cell producer in liquid medium. It represents a promising solution for wider biotechnological applications of this outstanding enzyme.

Catheter ablation versus antiarrhythmic drugs with risk factor modification for treatment of atrial fibrillation: a protocol of a randomised controlled trial (PRAGUE-25 trial).

INTRODUCTION: Atrial fibrillation (AF), with a prevalence of 2%, is the most common cardiac arrhythmia. Catheter ablation (CA) has been documented to be superior to treatment by antiarrhythmic drugs (AADs) in terms of sinus rhythm maintenance. However, in obese patients, substantial weight loss was also associated with AF reduction. So far, no study has compared the modern non-invasive (AADs combined with risk factor modification (RFM)) approach with modern invasive (CA) treatment. The aim of the trial is to compare the efficacy of modern invasive (CA) and non-invasive (AADs with risk factor management) treatment of AF. METHODS AND ANALYSIS: The trial will be a prospective, multicentre, randomised non-inferiority trial. Patients with symptomatic AF and a body mass index >30 will be enrolled and randomised to the CA or RFM arm (RFM+AAD) in a 1:1 ratio. In the CA arm, pulmonary vein isolation (in combination with additional lesion sets in non-paroxysmal patients) will be performed. For patients in the RFM+AAD arm, the aim will be a 10% weight loss over 6-12 months, increased physical fitness and a reduction in alcohol consumption. The primary endpoint will be an episode of AF or regular atrial tachycardia lasting >30 s. The secondary endpoints include AF burden, clinical endpoints associated with AF reoccurrence, changes in the quality of life assessed using dedicated questionnaires, changes in cardiorespiratory fitness and metabolic endpoints. An AF freedom of 65% in the RFM+AAD and of 60% in the CA is expected; therefore, 202 patients will be enrolled to achieve the non-inferiority with 80% power, 5% one-sided alpha and a non-inferiority margin of 12%. ETHICS AND DISSEMINATION: The PRAGUE-25 trial will determine if modern non-invasive AF treatment strategies are non-inferior to CA. The study was approved by the Ethics Committee of the University Hospital Kralovske Vinohrady. Results of the study will be disseminated on scientific conferences and in peer-reviewed scientific journals. After the end of follow-up, data will be available upon request to principal investigator. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT04011800).

[Correlation of intracardiac pressures and electrical atrial potentials with morphology and function of overloaded atria assessed by echocardiography]. / Korelace intraatriálních elektrických potenciálu a tlaku s morfologickými a funkcními ukazateli pretízených síní stanovenými echokardiografií.

BACKGROUND: In patients with chronic complete heart block or single chamber pacing and preserved sinus depolarization, left and right atria (LA, RA) may suffer from increased intraatrial pressure resulting from atrioventricular dyssynchrony (AVDys), dilate and lose their contractile function. The purpose of the study was to find out whether any correlation exists between the echocardiographically measured LA, RA morphological and functional parameters on one hand and the intracardiac RA pressures and electrical potentials on the other hand in patients with chronic AVDys. METHODS: In 26 pts (77 +/- 10 years, 16 males), where a chronic AVDys was the most important patophysiological mechanism of atrial overloading, the intraatrial pressures (atrial, right ventricular, pulmonary arterial and wedge pressure/PWP/) and electrical potentials (upper, middle, lower part of RA and RA appendage) were correlated with atrial diameters, volumes, ejection fraction and filling parameters. RESULTS: There was a moderate inverse correlation between the LA ejection fraction and PWP: r = -0,489, p = 0,025 at a level of significance 0.05, but no relationship between PWP and LA size/volumes. No correlation between RA potentials or intracardiac pressures and RA morphologic or functional features were documented. CONCLUSIONS: In this study, an inverse correlation between the capillary wedge pressure and left atrial ejection fraction in pts with chronic atrioventricular dyssynchrony was documented. No other correlation between echocardiographic parameters and intracardiac pressures or electrical potentials was found.

Septal ventricular tachycardia with alternating LBBB-RBBB morphology in isolated ventricular noncompaction.

Knowledge on ventricular tachycardia (VT) in isolated ventricular noncompaction (IVNC) is limited. We report on a patient with IVNC who presented with cardiogenic shock due to an incessant drug-resistant VT that was cured by radiofrequency ablation. The VT had characteristics of a deep septal focal arrhythmia, which was distinctive by ablation-induced alternation of the rightward and leftward exits, and was difficult to ablate from either side of the ventricular septum.

Left atrial voltage during atrial fibrillation in paroxysmal and persistent atrial fibrillation patients.

BACKGROUND: Left atrial (LA) endocardial voltage characteristics assessed during atrial fibrillation (AF) have not been previously compared in different AF types. This study was aimed at investigating the LA voltages and volumes in patients with paroxysmal and persistent AF. METHODS: LA electroanatomic voltage maps acquired during AF were compared between consecutive patients without major structural heart disease undergoing first catheter ablation for paroxysmal AF (n = 100) or persistent AF (n = 100). The groups were comparable in baseline clinical characteristics. RESULTS: Patients with persistent AF presented with lower median LA voltage (median 0.41, interquartile range [IQR] 0.31-0.51 mV versus median 0.99, IQR 0.47-1.56 mV; P < 0.001), and maximum LA voltage (4.07 +/- 1.76 vs 6.42 +/- 2.16 mV; P < 0.001). They also had a higher proportion of the LA points exhibiting voltage <0.2 mV (30 +/- 20 vs 12 +/- 11%; P < 0.001) and voltage 0.2-1.0 mV (55 +/- 15 vs 42 +/- 19%; P < 0.001). They further displayed higher LA volume/body surface area (75 +/- 16 vs 58 +/- 13 mL/m(2); P < 0.001). In the multivariate regression model, both LA voltage (P < 10(-9)) and LA volume (P < 10(-5)) were significant determinants of AF type. CONCLUSION: Patients with persistent AF had significantly lower LA voltage compared with patients with paroxysmal AF even after adjustment for differences in indexed LA volume. LA voltage represents an independent covariate of clinical manifestation of AF.

Comparison of two modes of long-term ECG monitoring to assess the efficacy of catheter ablation for paroxysmal atrial fibrillation.

AIMS: Optimal ECG monitoring in detecting recurrences of atrial fibrillation (AF) or atrial tachycardia (AT) after catheter ablation has not been well established. The purpose of this prospective study was to compare the utility of daily ECG monitoring with episodic card recorder (ECR) vs. periodic monitoring with episodic loop recorder (ELR) for the detection of post-blanking AF/AT recurrences during early (Months 4-6) and late (Months 7-12) periods after catheter ablation for paroxysmal AF. METHODS: The study included 105 consecutive patients, who received ECR for 12 months and were instructed to send at least 2 random ECG recordings daily with extra-recordings during symptoms. The patients were simultaneously monitored for one week with ELR at the end of each period (Months 6 and 12). RESULTS: Thirty-one and 12 patients with AF/AT recurrence were identified by means of ECR and ELR, respectively. In patients with complete and valid data, ELR technology was inferior to ECR by detecting AF/AT in 5 (31%) of 16 and 5 (26%) of 19 patients with arrhythmia identified by ECR in the early and late period, respectively. Overall, ELR had a sensitivity of 8/23 (35%) for detecting AF/AT recurrence. There was no single patient with AF/AT recurrence on ELR that would not be known from ECR monitoring. Only 2 patients with arrhythmia recurrence were completely asymptomatic throughout the study period. CONCLUSION: Daily ECG monitoring with ECR was better than periodic monitoring with ELR in detecting AF/AT recurrences during the follow-up periods. Entirely asymptomatic patients with AF/AT recurrences were rare.

Termination of long-lasting persistent versus short-lasting persistent and paroxysmal atrial fibrillation by ablation.

BACKGROUND: Left atrial (LA) structures for the maintenance of different atrial fibrillation (AF) forms are not uniform. The incidence, electrophysiological patterns, and LA sites of sinus rhythm (SR) restoration during ablation of different AF forms were evaluated. METHODS: One hundred patients with long-lasting persistent AF were retrospectively compared to 35 patients with short-lasting persistent AF and 59 patients with a sustained episode of paroxysmal AF. All patients underwent a first ablation using a stepwise ablation approach with the endpoint of SR restoration by ablation. RESULTS: SR was restored in 38%, 83%, and 97% of patients with long-lasting persistent, short-lasting persistent, and paroxysmal AF, respectively (P <0.001 for long-lasting persistent vs paroxysmal AF; P = 0.02 for long-lasting persistent vs short-lasting persistent AF). When modes and sites of SR restoration were evaluated among the patients with long-lasting persistent, short-lasting persistent, and paroxysmal AF, SR was restored via conversion into LA tachycardia in 79%, 52%, and 4% of patients (P <0.001 for long-lasting persistent vs paroxysmal AF); by the pulmonary vein encircling in 8%, 24%, and 93% patients (P <0.001 for long-lasting persistent vs paroxysmal AF); and by ablation at the LA anterior wall or inside the coronary sinus in 66%, 45%, and 2% patients (P <0.001 for long-lasting persistent and paroxysmal AF). During the 31 +/- 14 month follow-up since the first ablation, of the 50 patients with long-term SR maintenance (38 patients free of class I or III antiarrhythmic drugs), SR was restored by ablation in 29 (58%) patients versus nine (18%) patients out of 50 patients with unsuccessful clinical outcome (P = 0.009). CONCLUSION: Ablation of long-lasting persistent AF was characterized by more frequent failure to restore SR, and predominant conversion into LA tachycardia prior to SR restoration, and SR restoration by ablation outside the LA posterior wall. SR restoration by ablation was associated with better clinical outcome in these patients.

Pulmonary vein isolation using segmental versus electroanatomical circumferential ablation for paroxysmal atrial fibrillation: over 3-year results of a prospective randomized study.

PURPOSE: We tested the hypothesis that electroanatomic pulmonary vein (PV) antra encircling for the PV isolation will improve the outcome in treatment of paroxysmal atrial fibrillation (PAF), compared with segmental PV isolation. METHODS: Fifty-four patients underwent segmental PV isolation (group 1) and 56 patients circumferential PV isolation (group 2) for symptomatic PAF in a randomized study. RESULTS: Following single ablation procedure, at the 48 +/- 8 month follow-up, 30 (56%) and 32 (57%) patients in groups 1 and 2 remained free of arrhythmia (P = 0.41). After repeat ablation, 43 (80%) and 45 (80%) patients in groups 1 and 2 were free of arrhythmia without antiarrhythmic drugs (AADs); 48 (89%) and 51 (91%) patients in groups 1 and 2 did not have arrhythmia recurrences without or with AADs. CONCLUSION: This study demonstrates no advantage in long-term arrhythmia-free clinical outcome after circumferential PV isolation in patients with frequent PAF.

Results of complex left atrial ablation of long-lasting persistent atrial fibrillation.

PURPOSE: The aim of the study was to identify variables associated with successful long-term maintenance of sinus rhythm (SR) after a single ablation of long-lasting persistent atrial fibrillation (AF). METHODS: Complex left atrial (LA) ablation was performed in 100 patients. Restoration of SR by ablation was the desired procedure endpoint. RESULTS: SR was restored by ablation in 38 patients during the first procedure. Following one ablation, 50 patients remained in SR for 31 +/- 14 months. SR maintenance was associated with shorter duration of the persistent AF (median 14 vs. 22 months; P = 0.05), lower proportion of the LA points exhibiting voltage <0.2 mV (median 20% vs. 33%; P = 0.006), and higher proportion of LA points showing voltage >1 mV (median 15% vs. 11%; P = 0.02). CONCLUSION: Among clinical variables, shorter duration of persistent AF and higher voltage recorded around the LA predicted long-term maintenance of SR after single ablation.

Atrial macroreentry tachycardia in patients without obvious structural heart disease or previous cardiac surgical or catheter intervention: characterization of arrhythmogenic substrates, reentry circuits, and results of catheter ablation.

INTRODUCTION: Atrial macroreentry tachycardia (AMRT) in patients without obvious structural heart disease or previous surgical or catheter intervention has not been characterized in detail. METHODS AND RESULTS: Electroanatomical mapping and ablation of right or left AMRT were performed in 33 patients. Right atrial central conduction obstacle was formed by an electrically silent area (ESA) in 15 (68%) patients and by a line of double potentials (DPs) in seven (32%) patients. Left atrial ESAs were found in all 11 patients with the left AMRT. Reentry circuit was reconstructed in 19 (86%) patients with right AMRT and seven (64%) patients with left AMRT. Of the ESA-related right AMRT, eight (50%) were double-loop reentry circuits utilizing a narrow critical isthmus within the ESA and eight (50%) were single-loop reentry circuits with a critical isthmus bounded by ESA and either ostium of the vena cava. Single-loop DP-related AMRTs had the critical isthmus between the DP line and the ostium of the inferior vena cava (IVC). Left AMRTs included a variety of single-, double-, or triple-loop reentry circuits and their critical isthmuses. During the 37 +/- 15 month follow-up, atrial tachyarrhythmia-free clinical outcome was achieved in 21 (95%) patients (18 patients, 82%, without antiarrhythmic drugs) with the right AMRT and in nine (82%) patients (six patients, 55%, without antiarrhythmic drugs) with the left AMRT. CONCLUSION: The majority of right and left AMRTs were related to the presence of ESA. Ablation can be successful with a favorable risk of atrial tachyarrhythmia recurrence.

Conduction recovery following catheter ablation in patients with recurrent atrial fibrillation and heart failure.

BACKGROUND: Atrial fibrillation (AF) catheter ablation is increasingly proposed for patients suffering from AF and concomitant heart failure (HF). However, the optimal ablation strategy remains controversial. We performed this study to assess the prevalence of pulmonary vein (PV) or linear lesion reconnection in HF patients undergoing repeated procedures. METHODS AND RESULTS: At seven high-volume centres, 165 patients with HF underwent a repeat procedure after a first AF ablation including PV isolation alone (47 patients, group A) or PV isolation plus left atrial lines (118 patients, group B). Group A patients presented more often paroxysmal AF (p<0.001), less enlarged left atrium (p<0.001) and less left ventricular systolic dysfunction (p=0.031) compared to Group B, that more commonly had atypical atrial flutter (p<0.001). Forty-one (87%) patients in Group A and 69 (58%) in Group B presented at least one reconnected PV (p<0.001). Sixty-one (52%) patients in Group B presented at least one reconnected atrial line (left isthmus or roof). Patients without any reconnected PV (n=54, 33%) more frequently experienced persistent AF (p<0.001), had longer AF duration (p=0.047) and larger left atrial volume (p<0.001). Twenty-five patients (15%) with no PV and/or line reconnection did not significantly differ, concerning baseline characteristics, compared to those with at least one reconnected ablation site. CONCLUSION: As in the general AF population undergoing catheter ablation, PV reconnection is frequent in patients with HF and symptomatic recurrence. However, one third of patients presented arrhythmic recurrences even in the absence of PV reconnection, highlighting the importance of the underlying atrial substrate.