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Europace : European Pacing,... Nov 2023Areas of conduction inhomogeneity (CI) during sinus rhythm may facilitate the initiation and perpetuation of atrial fibrillation (AF). Currently, no tool is available to...
AIMS
Areas of conduction inhomogeneity (CI) during sinus rhythm may facilitate the initiation and perpetuation of atrial fibrillation (AF). Currently, no tool is available to quantify the severity of CI. Our aim is to develop and validate a novel tool using unipolar electrograms (EGMs) only to quantify the severity of CI in the atria.
METHODS AND RESULTS
Epicardial mapping of the right atrium (RA) and left atrium, including Bachmann's bundle, was performed in 235 patients undergoing coronary artery bypass grafting surgery. Conduction inhomogeneity was defined as the amount of conduction block. Electrograms were classified as single, short, long double (LDP), and fractionated potentials (FPs), and the fractionation duration of non-single potentials was measured. The proportion of low-voltage areas (LVAs, <1 mV) was calculated. Increased CI was associated with decreased potential voltages and increased LVAs, LDPs, and FPs. The Electrical Fingerprint Score consisting of RA EGM features, including LVAs and LDPs, was most accurate in predicting CI severity. The RA Electrical Fingerprint Score demonstrated the highest correlation with the amount of CI in both atria (r = 0.70, P < 0.001).
CONCLUSION
The Electrical Fingerprint Score is a novel tool to quantify the severity of CI using only unipolar EGM characteristics recorded. This tool can be used to stage the degree of conduction abnormalities without constructing spatial activation patterns, potentially enabling early identification of patients at high risk of post-operative AF or selection of the appropriate ablation approach in addition to pulmonary vein isolation at the electrophysiology laboratory.
Topics: Humans; Atrial Fibrillation; Heart Rate; Heart Atria; Epicardial Mapping; Atrioventricular Node
PubMed: 37931071
DOI: 10.1093/europace/euad324 -
Current Cardiology Reports Aug 2014Atrial fibrillation (AF) is the most common arrhythmia targeted by catheter ablation. Despite significant advances in our understanding of AF, ablation outcomes remain... (Review)
Review
Atrial fibrillation (AF) is the most common arrhythmia targeted by catheter ablation. Despite significant advances in our understanding of AF, ablation outcomes remain suboptimal, and this is due in large part to an incomplete understanding of the underlying sustaining mechanisms of AF. Recent developments of patient-tailored and physiology-based computational mapping systems have identified localized electrical spiral waves, or rotors, and focal sources as mechanisms that may represent novel targets for therapy. This report provides an overview of Focal Impulse and Rotor Modulation (FIRM) mapping, which reveals that human AF is often not actually driven by disorganized activity but instead that disorganization is secondary to organized rotors or focal sources. Targeted ablation of such sources alone can eliminate AF and, when added to pulmonary vein isolation, improves long-term outcome compared with conventional ablation alone. Translating mechanistic insights from such patient-tailored mapping is likely to be crucial in achieving the next major advances in personalized medicine for AF.
Topics: Atrial Fibrillation; Catheter Ablation; Electrocardiography; Heart Atria; Heart Conduction System; Humans
PubMed: 24950671
DOI: 10.1007/s11886-014-0509-0 -
JACC. Clinical Electrophysiology Mar 2021
Topics: Atrial Fibrillation; Catheter Ablation; Cicatrix; Embolic Stroke; Heart Atria; Humans
PubMed: 33736752
DOI: 10.1016/j.jacep.2020.12.002 -
BMC Cardiovascular Disorders Feb 2022Left atrial roof-dependent tachycardias (LARTs) are common macroreentrant atrial tachycardias (ATs). We sought to characterize clinical LARTs using an ultra-high...
BACKGROUND
Left atrial roof-dependent tachycardias (LARTs) are common macroreentrant atrial tachycardias (ATs). We sought to characterize clinical LARTs using an ultra-high resolution mapping system.
METHODS
This study included 22 consecutive LARTs in 21 patients who underwent AT mapping/ablation using Rhythmia systems.
RESULTS
Three, 13, 4, and 2 LART patients were cardiac intervention naïve (Group-A), post-roof line ablation (Group-B), post-atrial fibrillation ablation without linear ablation (Group-C), and post-cardiac surgery (Group-D), respectively. The mean AT cycle length was 244 ± 43 ms. Coronary sinus activation was proximal-to-distal or distal-to-proximal in 16 (72.7%) ATs. The activation map revealed 13 (59.1%) clockwise and 9 (40.9%) counter-clockwise LARTs. A 12-lead synchronous isoelectric interval was observed in 10/19 (52.6%) LARTs. The slow conduction area was identified on the LA roof, anterior/septal wall, and posterior wall in 18, 6, and 2 ATs, respectively. Twenty concomitant ATs among 13 procedures were also eliminated, and peri-mitral AT coexisted in 7 of 9 non-group-B patients. In group-B, the conduction gap was predominantly located on the mid-roof. Sustained LARTs were terminated by a single application and linear ablation in 6 (27.3%) and 9 (40.9%), while converting to other ATs in 7 (31.8%) LARTs. Complete linear block was created without any complications in all, however, ablation at the mid-posterior wall was required to achieve block in 4 (18.2%) procedures. During 14.0 (6.5-28.5) months of follow-up, 17 (81.0%) and 19 (90.5%) patients were free from any atrial tachyarrhythmias after single and last procedures.
CONCLUSIONS
The LART mechanisms were distinct in individual patients, and elimination of all concomitant ATs was required for the management.
Topics: Action Potentials; Aged; Aged, 80 and over; Catheter Ablation; Electrophysiologic Techniques, Cardiac; Female; Heart Atria; Heart Rate; Humans; Male; Middle Aged; Predictive Value of Tests; Recurrence; Tachycardia, Supraventricular; Time Factors; Treatment Outcome
PubMed: 35172730
DOI: 10.1186/s12872-022-02505-z -
International Journal of Molecular... Mar 2023ANP is mainly synthesized by the atria, and upon excretion, it serves two primary purposes: vasodilation and increasing the renal excretion of sodium and water. The... (Review)
Review
ANP is mainly synthesized by the atria, and upon excretion, it serves two primary purposes: vasodilation and increasing the renal excretion of sodium and water. The understanding of ANP's role in cardiac systems has improved considerably in recent decades. This review focuses on several studies demonstrating the importance of analyzing the regulations between the endocrine and mechanical function of the heart and emphasizes the effect of ANP, as the primary hormone of the atria, on atrial fibrillation (AF) and related diseases. The review first discusses the available data on the diagnostic and therapeutic applications of ANP and then explains effect of ANP on heart failure (HF) and atrial fibrillation (AF) and vice versa, where tracking ANP levels could lead to understanding the pathophysiological mechanisms operating in these diseases. Second, it focuses on conventional treatments for AF, such as cardioversion and catheter ablation, and their effects on cardiac endocrine and mechanical function. Finally, it provides a point of view about the delayed recovery of cardiac mechanical and endocrine function after cardioversion, which can contribute to the occurrence of acute heart failure, and the potential impact of restoration of the sinus rhythm by extensive ablation or surgery in losing ANP-producing sites. Overall, ANP plays a key role in heart failure through its effects on vasodilation and natriuresis, leading to a decrease in the activity of the renin-angiotensin-aldosterone system, but it is crucial to understand the intimate role of ANP in HF and AF to improve their diagnosis and personalizing the patients' treatment.
Topics: Humans; Atrial Fibrillation; Atrial Natriuretic Factor; Heart Atria; Heart Failure; Amyloidosis
PubMed: 37047444
DOI: 10.3390/ijms24076470 -
Europace : European Pacing,... Aug 2023The relationship between local unipolar voltage (UV) in the pulmonary vein (PV)-ostia and left atrial wall thickness (LAWT) and the utility of these parameters as...
AIMS
The relationship between local unipolar voltage (UV) in the pulmonary vein (PV)-ostia and left atrial wall thickness (LAWT) and the utility of these parameters as indices of outcome after atrial fibrillation (AF) ablation remain unclear.
METHODS AND RESULTS
Two-hundred seventy-two AF patients who underwent AF ablation were enrolled. Unipolar voltage of PV-ostia was measured using a CARTO system, and LAWT was measured using computed tomography. The primary endpoint was atrial tachyarrhythmia (ATA) recurrence including AF. The ATA recurrence was documented in 74 patients (ATA-Rec group). The UV and LAWT of the bilateral superior PV roof to posterior and around the right-inferior PV in the ATA-Rec group were significantly greater than in patients without ATA recurrence (ATA-Free group) (P < 0.001). The UV had a strong positive correlation with LAWT (R2 = 0.446, P < 0.001). The UV 2.7 mV and the corresponding LAWT 1.6 mm were determined as the cut-off values for ATA recurrence (P < 0.001, respectively). Multisite LA high UV (HUV, ≥4 areas of >2.7 mV) or multisite LA wall thickening (≥5 areas of >1.6 mm), defined as LA hypertrophy (LAH), was related to higher ATA recurrence. Among 92 LAH patients, 66 had HUV (LAH-HUV) and the remaining 26 had low UV (LAH-LUV), characterized by history of non-paroxysmal AF and heart failure, reduced LV ejection fraction, or enlarged LA. In addition, LAH-LUV showed the worst ablation outcome, followed by LAH-HUV and No LAH (log-rank P < 0.001).
CONCLUSION
Combining UV and LAWT enables us to stratify recurrence risk and suggest a tailored ablation strategy according to LA tissue properties.
Topics: Humans; Atrial Fibrillation; Heart Atria; Atrial Appendage; Tachycardia; Tomography, X-Ray Computed; Catheter Ablation; Pulmonary Veins; Recurrence; Treatment Outcome
PubMed: 37539865
DOI: 10.1093/europace/euad240 -
European Heart Journal. Cardiovascular... Dec 2021Atrial arrhythmias, including atrial fibrillation and atrial flutter, may be treated through catheter ablation. The process of atrial arrhythmia catheter ablation, which... (Review)
Review
Atrial arrhythmias, including atrial fibrillation and atrial flutter, may be treated through catheter ablation. The process of atrial arrhythmia catheter ablation, which includes patient selection, pre-procedural planning, intra-procedural guidance, and post-procedural assessment, is typically characterized by the use of several imaging modalities to sequentially inform key clinical decisions. Increasingly, advanced imaging modalities are processed via specialized image analysis techniques and combined with intra-procedural electrical measurements to inform treatment approaches. Here, we review the use of multimodality imaging for left atrial ablation procedures. The article first outlines how imaging modalities are routinely used in the peri-ablation period. We then describe how advanced imaging techniques may inform patient selection for ablation and ablation targets themselves. Ongoing research directions for improving catheter ablation outcomes by using imaging combined with advanced analyses for personalization of ablation targets are discussed, together with approaches for their integration in the standard clinical environment. Finally, we describe future research areas with the potential to improve catheter ablation outcomes.
Topics: Atrial Fibrillation; Atrial Flutter; Catheter Ablation; Heart Atria; Humans; Multimodal Imaging; Treatment Outcome
PubMed: 34747450
DOI: 10.1093/ehjci/jeab205 -
European Journal of Cardio-thoracic... Apr 2018Atrial fibrillation (AF) is the most common cardiac arrhythmia and the treatment options include medical treatment and catheter-based or surgical interventions. AF is a... (Review)
Review
Atrial fibrillation (AF) is the most common cardiac arrhythmia and the treatment options include medical treatment and catheter-based or surgical interventions. AF is a major cause of stroke, and its prevalence is increasing. The surgical treatment of AF has been revolutionized over the past 2 decades through surgical innovation and improvements in endoscopic imaging, ablation technology and surgical instrumentation. The Cox-maze (CM) procedure, which was developed by James Cox and introduced clinically in 1987, is a procedure in which multiple incisions are created in both the left and the right atria to eliminate AF while allowing the sinus impulse to reach the atrioventricular node. This procedure became the gold standard for the surgical treatment of AF. Its latest iteration is termed the CM IV and was introduced in 2002. The CM IV replaced the previous cut-and-sew method (CM III) by replacing most of the incisions with a combination of bipolar radiofrequency and cryoablation. The use of ablation technologies, made the CM IV technically easier, faster and more amenable to minimally invasive approaches. The aims of this article are to review the indications and preoperative planning for the CM IV, to describe the operative technique and to review the literature including comparisons of the CM IV with the previous cut-and-sew method. Finally, this review explores future directions for the surgical treatment of patients with AF.
Topics: Atrial Fibrillation; Catheter Ablation; Heart Atria; Humans; Minimally Invasive Surgical Procedures; Treatment Outcome
PubMed: 29590383
DOI: 10.1093/ejcts/ezx326 -
European Heart Journal Jan 2017Catheter ablation is increasingly offered to patients who suffer from symptoms due to atrial fibrillation (AF), based on a growing body of evidence illustrating its... (Review)
Review
Catheter ablation is increasingly offered to patients who suffer from symptoms due to atrial fibrillation (AF), based on a growing body of evidence illustrating its efficacy compared with antiarrhythmic drug therapy. Approximately one-third of AF ablation procedures are currently performed in patients with persistent or long-standing persistent AF. Here, we review the available information to guide catheter ablation in these more chronic forms of AF. We identify the following principles: Our clinical ability to discriminate paroxysmal and persistent AF is limited. Pulmonary vein isolation is a reasonable and effective first approach for catheter ablation of persistent AF. Other ablation strategies are being developed and need to be properly evaluated in controlled, multicentre trials. Treatment of concomitant conditions promoting recurrent AF by life style interventions and medical therapy should be a routine adjunct to catheter ablation of persistent AF. Early rhythm control therapy has a biological rationale and trials evaluating its value are underway. There is a clear need to generate more evidence for the best approach to ablation of persistent AF beyond pulmonary vein isolation in the form of adequately powered controlled multi-centre trials.
Topics: Anti-Arrhythmia Agents; Atrial Fibrillation; Cardiac Resynchronization Therapy; Catheter Ablation; Chronic Disease; Heart Atria; Humans; Pulmonary Veins; Secondary Prevention; Treatment Outcome
PubMed: 27389907
DOI: 10.1093/eurheartj/ehw260 -
International Journal of Cardiology Jul 2019Atrial fibrillation is the most common arrhythmia in humans and is associated with high morbidity, mortality and health-related expenses. Computational approaches have... (Review)
Review
Atrial fibrillation is the most common arrhythmia in humans and is associated with high morbidity, mortality and health-related expenses. Computational approaches have been increasingly utilized in atrial electrophysiology. In this review we summarize the recent advancements in atrial fibrillation modeling at the organ scale. Multi-scale atrial models now incorporate high level detail of atrial anatomy, tissue ultrastructure and fibrosis distribution. We provide the state-of-the art methodologies in developing personalized atrial fibrillation models with realistic geometry and tissue properties. We then focus on the use of multi-scale atrial models to gain mechanistic insights in AF. Simulations using atrial models have provided important insight in the mechanisms underlying AF, showing the importance of the atrial fibrotic substrate and altered atrial electrophysiology in initiation and maintenance of AF. Last, we summarize the translational evidence that supports incorporation of computational modeling in clinical practice for development of personalized treatment strategies for patients with AF. In early-stages clinical studies, AF models successfully identify patients where pulmonary vein isolation alone is not adequate for treatment of AF and suggest novel targets for ablation. We conclude with a summary of the future developments envisioned for the field of atrial computational electrophysiology.
Topics: Atrial Fibrillation; Catheter Ablation; Computer Simulation; Heart Atria; Humans; Imaging, Three-Dimensional; Magnetic Resonance Imaging, Cine; Models, Cardiovascular; Tomography, X-Ray Computed
PubMed: 30755334
DOI: 10.1016/j.ijcard.2019.01.096