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Cardiology Journal 2020Catheter ablation (CA) is a well-known treatment option for patients with symptomatic drug-resistant atrial fibrillation (AF). Multiple factors have been identified to... (Review)
Review
BACKGROUND
Catheter ablation (CA) is a well-known treatment option for patients with symptomatic drug-resistant atrial fibrillation (AF). Multiple factors have been identified to determine AF recurrence after CA, however their predictive value is rather small. Identification of novel predictors of CA outcome is therefore of primary importance to reduce health costs and improve long-term results of intervention. The recurrence of AF following CA is related to severity of left ventricular (LV) dysfunction, extent of atrial dilatation and fibrosis. The aim of this paper was to present and discuss the latest studies on the utility of echocardiographic parameters in terms of CA effectiveness in patients with paroxysmal and persistent AF.
METHODS
PubMed, Google Scholar, EBSCO databases were searched for studies reporting echocardiographic preprocedural predictors of AF recurrence after CA. LV systolic and diastolic function, as well as atrial size, strain and dyssynchrony were taken into consideration.
RESULTS
Twenty one full-text articles were analyzed, including three meta-analyses. Several echocardiographic parameters have been reported to determine a risk of AF recurrence after CA. There are conventional methods that measure left atrial size and volume, LV ejection fraction, parameters assessing LV diastolic dysfunction, and methods using more innovative technologies based on speckle tracking echocardiography to determine left atrial synchrony and strain. Each of these parameters has its own predictive value.
CONCLUSIONS
Regarding CA effectiveness, every patient has to be evaluated individually to estimate the risk of AF recurrence, optimally using a combination of several echocardiographic parameters.
Topics: Atrial Fibrillation; Catheter Ablation; Echocardiography; Heart Atria; Humans; Predictive Value of Tests; Recurrence; Treatment Outcome
PubMed: 29924375
DOI: 10.5603/CJ.a2018.0067 -
Journal of the American College of... Jul 2021
Topics: Atrial Appendage; Atrial Fibrillation; Humans; Thrombosis
PubMed: 34294268
DOI: 10.1016/j.jacc.2021.05.028 -
Cardiovascular Research Jun 2022Recent developments in imaging, mapping, and ablation techniques have shown that the epicardial region of the heart is a key player in the occurrence of ventricular... (Review)
Review
Recent developments in imaging, mapping, and ablation techniques have shown that the epicardial region of the heart is a key player in the occurrence of ventricular arrhythmic events in several cardiac diseases, such as Brugada syndrome, arrhythmogenic cardiomyopathy, or dilated cardiomyopathy. At the atrial level as well, the epicardial region has emerged as an important determinant of the substrate of atrial fibrillation, pointing to common underlying pathophysiological mechanisms. Alteration in the gradient of repolarization between myocardial layers favouring the occurrence of re-entry circuits has largely been described. The fibro-fatty infiltration of the subepicardium is another shared substrate between ventricular and atrial arrhythmias. Recent data have emphasized the role of the epicardial reactivation in the formation of this arrhythmogenic substrate. There are new evidences supporting this structural remodelling process to be regulated by the recruitment of epicardial progenitor cells that can differentiate into adipocytes or fibroblasts under various stimuli. In addition, immune-inflammatory processes can also contribute to fibrosis of the subepicardial layer. A better understanding of such 'electrical fragility' of the epicardial area will open perspectives for novel biomarkers and therapeutic strategies. In this review article, a pathophysiological scheme of epicardial-driven arrhythmias will be proposed.
Topics: Atrial Fibrillation; Brugada Syndrome; Catheter Ablation; Heart Atria; Heart Ventricles; Humans; Myocardium
PubMed: 34152392
DOI: 10.1093/cvr/cvab213 -
Journal of the American College of... Jul 2020Atrial flutter (AFL) and atrial fibrillation (AF) are associated with AF-promoting atrial remodeling, but no experimental studies have addressed remodeling with...
BACKGROUND
Atrial flutter (AFL) and atrial fibrillation (AF) are associated with AF-promoting atrial remodeling, but no experimental studies have addressed remodeling with sustained AFL.
OBJECTIVES
This study aimed to define the atrial remodeling caused by sustained atrial flutter (AFL) and/or atrial fibrillation (AF).
METHODS
Intercaval radiofrequency lesions created a substrate for sustained isthmus-dependent AFL, confirmed by endocavity mapping. Four groups (6 dogs per group) were followed for 3 weeks: sustained AFL; sustained AF (600 beats/min atrial tachypacing); AF superimposed on an AFL substrate (AF+AFLs); sinus rhythm (SR) with an AFL substrate (SR+AFLs; control group). All dogs had atrioventricular-node ablation and ventricular pacemakers at 80 beats/min to control ventricular rate.
RESULTS
Monitoring confirmed spontaneous AFL maintenance >99% of the time in dogs with AFL. At terminal open-chest study, left-atrial (LA) effective refractory period was reduced similarly with AFL, AF+AFLs and AF, while AF vulnerability to extrastimuli increased in parallel. Induced AF duration increased significantly in AF+AFLs and AF, but not AFL. Dogs with AF+AFLs had shorter cycle lengths and substantial irregularity versus dogs with AFL. LA volume increased in AF+AFLs and AF, but not dogs with AFL, versus SR+AFLs. Optical mapping showed significant conduction slowing in AF+AFLs and AF but not AFL, paralleling atrial fibrosis and collagen-gene upregulation. Left-ventricular function did not change in any group. Transcriptomic analysis revealed substantial dysregulation of inflammatory and extracellular matrix-signaling pathways with AF and AF+ALs but not AFL.
CONCLUSIONS
Sustained AFL causes atrial repolarization changes like those in AF but, unlike AF or AF+AFLs, does not induce structural remodeling. These results provide novel insights into AFL-induced remodeling and suggest that early intervention may be important to prevent irreversible fibrosis when AF intervenes in a patient with AFL.
Topics: Animals; Atrial Fibrillation; Atrial Flutter; Atrial Remodeling; Catheter Ablation; Dogs; Electrocardiography; Fibrosis; Heart Atria
PubMed: 32703507
DOI: 10.1016/j.jacc.2020.05.062 -
Multimedia Manual of Cardiothoracic... Nov 2020Atrial fibrillation is becoming a disease that needs to be addressed with definitive long-term treatment as opposed to medical management options. Ablation or isolation...
Atrial fibrillation is becoming a disease that needs to be addressed with definitive long-term treatment as opposed to medical management options. Ablation or isolation of focal triggers around the pulmonary veins can eliminate arrhythmia substrates for patients with paroxysmal, lone atrial fibrillation. However, limited pulmonary vein isolation strategies do not address reentrant circuits common in persistent and longstanding persistent patients with structural heart disease and enlarged atria. The convergent procedure is a hybrid ablation treatment for atrial fibrillation. It consists of surgical ablation of the posterior left atrium through a minimally invasive closed-chest approach followed by endocardial catheter ablation. The convergent procedure was developed to treat atrial fibrillation by creating a complete and comprehensive pattern of linear lesions on the left atrial backwall under direct endoscopic visualization while avoiding chest incisions and deflation of the lungs. Endocardial ablation follows the epicardial procedure to confirm lesion integrity and supplement the epicardial procedure, which is performed in a staged fashion.
Topics: Atrial Appendage; Atrial Fibrillation; Catheter Ablation; Endocardium; Endoscopy; Heart Atria; Humans; Male; Middle Aged; Organ Size; Pulmonary Veins; Surgery, Computer-Assisted; Treatment Outcome; Xiphoid Bone
PubMed: 33263364
DOI: 10.1510/mmcts.2020.066 -
Journal of Interventional Cardiac... Oct 2022Understanding of the atrial fibrillation (AF) driven by right atrial appendage (RAA) is limited. This study aimed to understand the characteristics of the AF driven by...
PURPOSE
Understanding of the atrial fibrillation (AF) driven by right atrial appendage (RAA) is limited. This study aimed to understand the characteristics of the AF driven by RAA and explore ablation methods.
METHODS
This was a retrospective study and patients who were identified as having the AF driven by RAA were reviewed. Ablation was performed during AF. Potential maps of the left and right atrium, electrophysiological examinations, and ablation methods were studied.
RESULTS
Among the 20 identified patients (mean age 67.0 ± 11.2 years; ejection fraction 62.9 ± 6.0%; LA diameter 43.1 ± 4.9 mm; RA diameter 51.7 ± 8.3 × 42.9 ± 3.7 mm), the AF cycle length in RAA (134.0 ± 10.9 ms) was the shortest, and the fastest frequency potentials were located in the RAA in 65% of patients. For the left atrium, the AF cycle length of the roof (145.5 ± 14.9 ms) was the shortest, followed by the left atrial appendage (153.7 ± 17.1 ms) and bottom (154.8 ± 11.8 ms). High-frequency potentials of RAA could be rapidly conducted to left atrium via sagittal bundle and Bachmann's bundle, and the conduction time (55.0 ± 5.0 ms) was significantly shorter than the mean bi-atrial activation time (176.7 ± 10.3 ms, P < 0.0001). AF could be terminated after ablation at the RAA base (17 patients) or mechanical stimulation within the RAA (3 patients). To date, only two patients had recurrent atrial flutter, while the remaining patients maintained sinus rhythm.
CONCLUSION
The AF driven by RAA is characterized by high-frequency potentials in RAA, and ablation at the RAA base can achieve a satisfactory therapeutic effect.
Topics: Aged; Atrial Appendage; Atrial Fibrillation; Atrial Flutter; Catheter Ablation; Heart Atria; Humans; Middle Aged; Retrospective Studies
PubMed: 35179671
DOI: 10.1007/s10840-021-01106-8 -
JACC. Clinical Electrophysiology Nov 2020Atrial fibrillation is a common disease of increasing prevalence. Catheter ablation has evolved into an established therapeutic option that mainly aims to electrically... (Review)
Review
Atrial fibrillation is a common disease of increasing prevalence. Catheter ablation has evolved into an established therapeutic option that mainly aims to electrically isolate the pulmonary veins from atrial myocardium. The traditional method comprises point-by-point radiofrequency current ablation guided by electroanatomical mapping and has proven to be effective and safe in experienced hands. However, this approach is technically highly demanding and associated with a long learning curve, limiting its widespread utilization. To address these shortcomings, simplified ablation tools for pulmonary vein isolation are needed. In this context, balloon devices promise to ease the procedure by approaching the entire orifice of a targeted pulmonary vein in a single maneuver. This requires less catheter manipulation in the left atrium and often allows ablation of a large volume of tissue with a single application of ablative energy. Two balloon devices-one using cryoenergy, the other laser energy-have already been established in clinical routine and have demonstrated noninferiority when compared with radiofrequency ablation in large randomized trials. More balloon devices are on the verge of being introduced into clinical practice and bear the potential to expand the interventional electrophysiologist's armamentarium when treating atrial fibrillation. The authors review the use of the established balloon devices available for atrial fibrillation ablation and provide a detailed outlook on upcoming balloon technologies, including 3 different balloons utilizing radiofrequency energy as well as a novel cryoballoon.
Topics: Atrial Fibrillation; Catheter Ablation; Heart Atria; Humans; Pulmonary Veins
PubMed: 33213820
DOI: 10.1016/j.jacep.2020.08.041 -
Medical Image Analysis Apr 2022Late gadolinium enhancement magnetic resonance imaging (LGE MRI) is commonly used to visualize and quantify left atrial (LA) scars. The position and extent of LA scars... (Review)
Review
Late gadolinium enhancement magnetic resonance imaging (LGE MRI) is commonly used to visualize and quantify left atrial (LA) scars. The position and extent of LA scars provide important information on the pathophysiology and progression of atrial fibrillation (AF). Hence, LA LGE MRI computing and analysis are essential for computer-assisted diagnosis and treatment stratification of AF patients. Since manual delineations can be time-consuming and subject to intra- and inter-expert variability, automating this computing is highly desired, which nevertheless is still challenging and under-researched. This paper aims to provide a systematic review on computing methods for LA cavity, wall, scar, and ablation gap segmentation and quantification from LGE MRI, and the related literature for AF studies. Specifically, we first summarize AF-related imaging techniques, particularly LGE MRI. Then, we review the methodologies of the four computing tasks in detail and summarize the validation strategies applied in each task as well as state-of-the-art results on public datasets. Finally, the possible future developments are outlined, with a brief survey on the potential clinical applications of the aforementioned methods. The review indicates that the research into this topic is still in the early stages. Although several methods have been proposed, especially for the LA cavity segmentation, there is still a large scope for further algorithmic developments due to performance issues related to the high variability of enhancement appearance and differences in image acquisition.
Topics: Atrial Fibrillation; Cicatrix; Contrast Media; Gadolinium; Heart Atria; Humans; Magnetic Resonance Imaging
PubMed: 35124370
DOI: 10.1016/j.media.2022.102360 -
Current Cardiology Reviews 2021Atrial fibrillation is the most common supraventricular arrhythmia affecting an increasing proportion of the population in which mainstream therapy, i.e. catheter...
Atrial fibrillation is the most common supraventricular arrhythmia affecting an increasing proportion of the population in which mainstream therapy, i.e. catheter ablation, provides freedom from arrhythmia in only a limited number of patients. Understanding the mechanism is key in order to find more effective therapies and to improve patient selection. In this review, the structural and electrophysiological changes of the atrial musculature that constitute atrial remodeling in atrial fibrillaton and how risk factors and markers of disease progression can predict catheter ablation outcome will be discussed in detail.
Topics: Atrial Fibrillation; Atrial Remodeling; Catheter Ablation; Comorbidity; Disease Progression; Heart Atria; Humans; Treatment Outcome
PubMed: 32693769
DOI: 10.2174/1573403X16666200721153620 -
JACC. Clinical Electrophysiology Feb 2020The goal of this study was to find effective parameters that can be used in real-time that result in chronic scar verified by left atrial (LA) late gadolinium...
OBJECTIVES
The goal of this study was to find effective parameters that can be used in real-time that result in chronic scar verified by left atrial (LA) late gadolinium enhancement cardiac magnetic resonance (LGE-CMR).
BACKGROUND
Automated annotation can be a useful tool while ablating in tagging areas that will result in scar, but the effective settings that best predict chronic scar are still unknown.
METHODS
Patients underwent pulmonary vein isolation using a CARTO3 mapping system with a VISITAG Module and 3-month post-ablation LGE-CMR. The electroanatomical map (EAM) was used to retrospectively tag ablated areas with 5 different parameters: catheter stability; stability duration; force over time; minimum contact force; and impedance drop. The ablation tags in EAM were projected to the 3-month post-ablation LGE-CMR. Tags were divided into 2 groups depending on if they correlated with CMR-based scar tags (STAGs) or nonscar tags (NTAGs); the effective parameters were estimated for the 2 groups at different power levels.
RESULTS
This study assessed 70 consecutive patients and 28,939 ablation tags. Ablation time and force time integral (FTI) were significantly larger in the STAG group. Mean contact force, change of catheter tip temperature, and impedance were not significantly different between STAGs and NTAGs. The minimum ablation time and FTI to make durable scar lesions were 17.6, 13.6, and 11.0 s and 226.1, 187.4, and 161.4 g at 25, 35, and 50 W, respectively.
CONCLUSIONS
Minimum ablation time and FTI values are critical parameters that determine durable atrial scar creation and their minimum values vary with the ablation power setting.
Topics: Aged; Atrial Fibrillation; Cardiac Imaging Techniques; Catheter Ablation; Cicatrix; Female; Heart Atria; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Pulmonary Veins; Retrospective Studies; Treatment Outcome
PubMed: 32081215
DOI: 10.1016/j.jacep.2019.10.001