Persistent Atrial Fibrillation: The Role of Left Atrial Posterior Wall Isolation and Ablation Strategies.
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ABSTRACT:
SUBMITTER: Kaba RA
PROVIDER: S-EPMC8304563 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:A significant proportion of patients' experience recurrence of atrial fibrillation (AF) despite pulmonary venous isolation (PVI), especially those with persistent AF. Isolation of the left atrial appendage (LAA) may reduce AF recurrence. The aim of this study was to assess the efficacy of LAA isolation in addition to PVI compared with PVI alone. We conducted a comprehensive search of electronic databases, up to April 21st, 2017, for all studies comparing the effect LAA electrical isolation or ligation in addition to PVI, as opposed to PVI alone, on the recurrence of atrial fibrillation after catheter ablation. We used random-effects meta-analysis models to summarize the studies. One RCT and four observational studies enrolling 781 patients were retained. Four studies assessed the added effect of LAA catheter ablation, and one study evaluated the effect of LAA ligation with the aim of LAA electrical isolation. Four studies exclusively enrolled patients with persistent atrial fibrillation and one study predominantly enrolled patients with persistent atrial fibrillation. Follow-up ranged from 12 to 15 months. The addition of LAA isolation to PVI reduced AF recurrence compared with the latter alone (odds ratio (OR) = 0.19; 95% confidence intervals (CI) = 0.10-0.37; P < 0.00001). Left atrial appendage isolation was also associated with a reduction in AF recurrence after repeat ablation (OR = 0.40; CI = 0.25-0.65; P = 0.0003). The addition of LAA isolation to PVI was associated with a decrease in AF recurrence in patients with persistent AF. Further studies are needed to assess the effect on long-term risk of stroke.
| S-EPMC6174377 | biostudies-literature
Project description:There is strong evidence in support of pulmonary vein isolation (PVI) with concomitant left atrial (LA) posterior wall (PW) isolation (PWI) for the treatment of patients with persistent atrial fibrillation (persAF). While this may be achieved using surgical and catheter-based strategies, there is growing interest in performing this approach using the cryoballoon. There are several potential advantages to this strategy. First, lesions created using the current-generation cryoballoons are typically large and durable. Second, cryoballoon ablation offers a simple technique to directly ablate and debulk the LAPW. Moreover, some consider cryoenergy a safer modality specifically with regard to collateral structures (ie, the esophagus). Based on the available data, cryoballoon PVI + PWI is associated with greater intraprocedural AF terminations and reductions in long-term AF recurrence (typically by ~20%), as compared to PVI alone in patients with persAF, but with similar rates of adverse events. As such, PVI + PWI has emerged as a significant predictor of freedom from recurrent AF (odds ratio: 3.67, 95% confidence interval: 1.44-9.34; p = 0.006) as well as all atrial arrhythmias (hazard ratio: 2.04, 95% confidence interval: 1.15-3.61; p = 0.015). Adjunct radiofrequency ablation to complete PWI is required in at least one-third of the patients, and this need is highly predicted by the LA size (significantly increased with an LA diameter > 48 mm). LAPW reconnection also seems to be associated with LA dimension, particularly an LA diameter greater than 48 mm (negative predictive value: 89.7%). Nevertheless, based on the analysis of patients who underwent repeat electrophysiology study for arrhythmia recurrences, cryoballoon PVI + PWI yields acceptable long-term durability (> 80%).
| S-EPMC8384303 | biostudies-literature
Project description:We present the case of a 59-year-old patient with persistent atrial fibrillation, referred for atrial fibrillation ablation. The procedure was performed with the help of NAVX 3D mapping system (Saint Jude Medical) and iLAB Ultra ICE Plus ultrasound imaging catheter (Boston Scientific). The catheter permits cross-sectional images perpendicular to catheter's long axis. From inside left atrial appendage (LAA) looks trabeculated, due to pectinate muscles running parallel to each other. The presence of a thrombus was excluded from the appendage. The contractility of LAA was also assessed using multiple frames recorded on videotape. Our case demonstrates that LAA's morphology and function can be directly assessed by intracardiac ultrasound with the probe inserted inside the appendage.
| S-EPMC5761508 | biostudies-literature
Project description:BACKGROUND:Combined 'hybrid' thoracoscopic and percutaneous atrial fibrillation (AF) ablation is a strategy used to treat AF in patients with therapy-resistant symptomatic AF. We aimed to study efficacy and safety of single-stage hybrid AF ablation in patients with symptomatic persistent AF, or paroxysmal AF with failed endocardial ablation, and assess determinants of success and quality of life. METHODS:We included consecutive patients undergoing single-stage hybrid AF ablation. First, we performed epicardial ablation, via thoracoscopic access, to isolate the pulmonary veins and superior caval vein and to create a posterior left atrial box. Thereafter, isolation was assessed endocardially and complementary endocardial ablation was performed, followed by cavotricuspid isthmus ablation. Efficacy was assessed by 12-lead electrocardiography and 72-hour Holter monitoring after 3, 6 and 12 months. Recurrence was defined as AF/atrial flutter/tachycardia recorded by electrocardiography or Holter monitoring lasting >30?s during 1?year follow-up. RESULTS:Fifty patients were included, 57?±?9 years, 38 (76%) men, 5 (10%) paroxysmal, 34 (68%) persistent and 11 (22%) long-standing persistent AF. At 1?year 38 (76%) maintained sinus rhythm off antiarrhythmic drugs. Majority of recurrences were atrial flutter (9/12 patients). Success was associated with type of AF (p?=?0.039). Patients with paroxysmal AF had highest success, patients with longstanding persistent AF had lowest success. Seven (14%) patients had procedure-related complications. Quality of life improved after ablation in patients who maintained sinus rhythm. CONCLUSION:Success of single-stage hybrid AF ablation was 76% off antiarrhythmic drugs, being associated with type of AF. Quality of life improved significantly, Procedure-related complications occurred in 14%.
| S-EPMC6393682 | biostudies-literature
Project description:BackgroundAlthough Ablation Index (AI)-guided ablation facilitates creation of lesions of consistent depth, pulmonary vein (PV) reconnection is still commonly observed after AI-guided pulmonary vein isolation (PVI). The present study aimed to investigate the impact of local left atrial wall thickness on the incidence of acute PV reconnection after AI-guided atrial fibrillation (AF) ablation.Methods and resultsSeventy patients (63% paroxysmal AF, 67% male, mean age 63 ± 8 years) who underwent preprocedural CT imaging and AI-guided AF ablation were studied. Occurrence of acute PV reconnection after initial PVI was assessed after a 30-minute waiting period. Ablation procedures were retrospectively analyzed and each ablation circle was subdivided into 8 segments. Minimum AI, force-time integral, contact force, ablation duration, power, impedance drop and maximum interlesion distance were determined for each segment. PV antrum wall thickness was assessed for each segment on reconstructed CT images based on patient-specific thresholds in Hounsfield Units. Acute reconnection occurred in 27/1120 segments (2%, 15 anterior/roof, 12 posterior/inferior) in 19/140 ablation circles (14%). Reconnected segments were characterized by a greater local atrial wall thickness, both in anterior/roof (1.87 ± 0.42 vs. 1.54 ± 0.42 mm; p < 0.01) and posterior/inferior (1.43 ± 0.20 vs. 1.16 ± 0.22 mm; p < 0.01) segments. Minimum AI, force-time integral, contact force, ablation duration, power, impedance drop and maximum interlesion distance were not associated with acute reconnection.ConclusionsLocal atrial wall thickness is associated with acute pulmonary vein reconnection after AI-guided PVI. Individualized AI targets based on local wall thickness may be of use to create transmural ablation lesions and prevent PV reconnection after PVI.
| S-EPMC7334811 | biostudies-literature
Project description:Atrial stretch may contribute to the mechanism of atrial fibrillation (AF) recurrence after atrial fibrillation catheter ablation (AFCA). We tested whether the left atrial (LA) wall stress (LAW-stress[measured]) could be predicted by artificial intelligence (AI) using non-invasive parameters (LAW-stress[AI]) and whether rhythm outcome after AFCA could be predicted by LAW-stress[AI] in an independent cohort. Cohort 1 included 2223 patients, and cohort 2 included 658 patients who underwent AFCA. LAW-stress[measured] was calculated using the Law of Laplace using LA diameter by echocardiography, peak LA pressure measured during procedure, and LA wall thickness measured by customized software (AMBER) using computed tomography. The highest quartile (Q4) LAW-stress[measured] was predicted and validated by AI using non-invasive clinical parameters, including non-paroxysmal type of AF, age, presence of hypertension, diabetes, vascular disease, and heart failure, left ventricular ejection fraction, and the ratio of the peak mitral flow velocity of the early rapid filling to the early diastolic velocity of the mitral annulus (E/Em). We tested the AF/atrial tachycardia recurrence 3 months after the blanking period after AFCA using the LAW-stress[measured] and LAW-stress[AI] in cohort 1 and LAW-stress[AI] in cohort 2. LAW-stress[measured] was independently associated with non-paroxysmal AF (p < 0.001), diabetes (p = 0.012), vascular disease (p = 0.002), body mass index (p < 0.001), E/Em (p < 0.001), and mean LA voltage measured by electrogram voltage mapping (p < 0.001). The best-performing AI model had acceptable prediction power for predicting Q4-LAW-stress[measured] (area under the receiver operating characteristic curve 0.734). During 26.0 (12.0-52.0) months of follow-up, AF recurrence was significantly higher in the Q4-LAW-stress[measured] group [log-rank p = 0.001, hazard ratio 2.43 (1.21-4.90), p = 0.013] and Q4-LAW-stress[AI] group (log-rank p = 0.039) in cohort 1. In cohort 2, the Q4-LAW-stress[AI] group consistently showed worse rhythm outcomes (log-rank p < 0.001). A higher LAW-stress was associated with poorer rhythm outcomes after AFCA. AI was able to predict this complex but useful prognostic parameter using non-invasive parameters with moderate accuracy.
| S-EPMC8285096 | biostudies-literature
Project description:Pulmonary vein isolation (PVI) with radiofrequency ablation (RFA) is the cornerstone of atrial fibrillation (AF) therapy, but few strategies exist for when it fails. To guide RFA, phase singularity (PS) mapping locates reentrant electrical waves (rotors) that perpetuate AF. The goal of this study was to test existing and develop new RFA strategies for terminating rotors identified with PS mapping. It is unsafe to test experimental RFA strategies in patients, so they were evaluated in silico using a bilayer computer model of the human atria with persistent AF (pAF) electrical (ionic) and structural (fibrosis) remodeling. pAF was initiated by rapidly pacing the right (RSPV) and left (LSPV) superior pulmonary veins during sinus rhythm, and rotor dynamics quantified by PS analysis. Three RFA strategies were studied: (i) PVI, roof, and mitral lines; (ii) circles, perforated circles, lines, and crosses 0.5-1.5 cm in diameter/length administered near rotor locations/pathways identified by PS mapping; and (iii) 4-8 lines streamlining the sequence of electrical activation during sinus rhythm. As in pAF patients, 2 ± 1 rotors with cycle length 185 ± 4 ms and short PS duration 452 ± 401 ms perpetuated simulated pAF. Spatially, PS density had weak to moderate positive correlations with fibrosis density (RSPV: r = 0.38, p = 0.35, LSPV: r = 0.77, p = 0.02). RFA PVI, mitral, and roof lines failed to terminate pAF, but RFA perforated circles and lines 1.5 cm in diameter/length terminated meandering rotors from RSPV pacing when placed at locations with high PS density. Similarly, RFA circles, perforated circles, and crosses 1.5 cm in diameter/length terminated stationary rotors from LSPV pacing. The most effective strategy for terminating pAF was to streamline the sequence of activation during sinus rhythm with >4 RFA lines. These results demonstrate that co-localizing 1.5 cm RFA lesions with locations of high PS density is a promising strategy for terminating pAF rotors. For patients immune to PVI, roof, mitral, and PS guided RFA strategies, streamlining patient-specific activation sequences during sinus rhythm is a robust but challenging alternative.
| S-EPMC4828663 | biostudies-literature
Project description:Atrial fibrillation (AF)-the most common arrhythmia-significantly increases the risk of stroke and heart failure. Although catheter ablation can restore normal heart rhythms, patients with persistent AF who develop atrial fibrosis often undergo multiple failed ablations, and thus increased procedural risks. Here, we present personalized computational modelling for the reliable predetermination of ablation targets, which are then used to guide the ablation procedure in patients with persistent AF and atrial fibrosis. First, we show that a computational model of the atria of patients identifies fibrotic tissue that, if ablated, will not sustain AF. Then, we report the results of integrating the target ablation sites in a clinical mapping system and testing its feasibility in ten patients with persistent AF. The computational prediction of ablation targets avoids lengthy electrical mapping and could improve the accuracy and efficacy of targeted AF ablation in patients while eliminating the need for repeat procedures.
| S-EPMC6842421 | biostudies-literature
Project description:BackgroundLeft atrial volume index (LAVI) of >34 mL/m2 is the cutoff value for identifying an enlarged left atrium. The definition of left atrial (LA) reverse remodeling after atrial fibrillation (AF) ablation is undetermined. We hypothesized that patients with LA dilatation who achieve normal LA volume (LAVI<34 mL/m2) after AF ablation have better long-term outcomes than those who do not. Furthermore, we investigated whether patients with a normal LA volume can also achieve normal LA function with AF ablation.MethodsWe enrolled 140 AF patients with baseline LAVI of ≥34 mL/m2, without AF recurrence for 1 year after the initial AF ablation. We acquired conventional and speckle-tracking echocardiographic parameters within 24 hour and at 1 year after the procedure. To define the normal range of LA function, age- and sex-matched controls without a history of AF were also enrolled.ResultsAfter restoration of sinus rhythm, LA structural and functional parameters significantly improved, and 75 patients (54%) had normal LA volume. During a median follow-up of 44 (31-61) months, 32 patients (23%) experienced a late recurrence of AF (AF recurrence >1 year). Patients who achieved normal LA volume after AF ablation had fewer late recurrences than those who did not (P < .01). However, LA abnormalities, especially LA dysfunction, persisted in AF patients even when the LA volume was normalized compared with controls.ConclusionPatients who achieved normal LA volume had better long-term outcomes of AF ablation than those who did not; however, LA abnormalities persisted even after successful ablation of AF.
| S-EPMC8485788 | biostudies-literature
Project description:The management of non-paroxysmal atrial fibrillation (AF) remains controversial. We examined the efficacy and safety of the 2 stage Hybrid AF ablation approach by analysing the largest series of this technique reported so far.MethodsThe approach aims to electrically isolate the left atrial posterior wall incorporating the pulmonary veins ('box-set'pattern). An initial video-assisted thoracoscopic (VATS) epicardial ablation is followed after a minimum of 8 weeks by endocardial radiofrequency catheter ablation.ResultsOf 175 patients from 4 European cardiothoracic centers, who underwent the surgical (COBRA Fusion, AtriCure Inc) 1st stage ablation, 166 went on to complete 2nd stage catheter ablation. At median follow up of 18 months post 2nd stage procedure 93/166 (56%) had remained free of AF or atrial tachycardia (AT) recurrence off antiarrhythmic drugs. 110/175 62.9% were in sinus rhythm off all antiarrhythmic drugs at last clinic follow-up (132/175 75.4% including those on antiarrhythmic drugs). 18 patients (10.8%) underwent a further re-do ablation (mean of 1.1 ablations per patient) 105/166 (63%) remained free of AF/AT recurrence off antiarrhythmic drugs following last ablation procedure.Latterly, ILRs have been implanted in patients (n = 56); 60% have remained fully arrhythmia free and 80% have shown AF burden < 5% at a median 14 months follow-up [IQR: 13.5 (8-21.5)]. Only 10.9% have reverted to persistent AF. 5 patients (2.9%) had a perioperative stroke and 4 patients (2.3%) exhibited persistent weakness of the right hemidiaphragm following stage 1 VATS epicardial ablation. One patient died following stroke (overall mortality 0.6%).ConclusionsIn patients with non-paroxysmal AF with unfavourable characteristics for catheter ablation, the staged hybrid approach results in acceptable levels of freedom from recurrent atrial arrhythmia, however, complication rates are higher than with catheter ablation alone.
| S-EPMC7046539 | biostudies-literature