scholarly journals Location of Parasympathetic Innervation Regions From Electrograms to Guide Atrial Fibrillation Ablation Therapy: An in silico Modeling Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Chiara Celotto ◽  
Carlos Sánchez ◽  
Konstantinos A. Mountris ◽  
Pablo Laguna ◽  
Esther Pueyo
Keyword(s):  
Atrial Fibrillation ◽  
Signal To Noise Ratio ◽  
Diffuse Fibrosis ◽  
Noise Levels ◽  
Parasympathetic Innervation ◽  
Ablation Therapy ◽  
Optimal Thresholds ◽  
In Silico Modeling ◽  
Study Support ◽  
Af Recurrence

The autonomic nervous system (ANS) plays an essential role in the generation and maintenance of cardiac arrhythmias. The cardiac ANS can be divided into its extrinsic and intrinsic components, with the latter being organized in an epicardial neural network of interconnecting axons and clusters of autonomic ganglia called ganglionated plexi (GPs). GP ablation has been associated with a decreased risk of atrial fibrillation (AF) recurrence, but the accurate location of GPs is required for ablation to be effective. Although GP stimulation triggers both sympathetic and parasympathetic ANS branches, a predominance of parasympathetic activity has been shown. This study aims was to develop a method to locate atrial parasympathetic innervation sites based on measurements from a grid of electrograms (EGMs). Electrophysiological models representative of non-AF, paroxysmal AF (PxAF), and persistent AF (PsAF) tissues were developed. Parasympathetic effects were modeled by increasing the concentration of the neurotransmitter acetylcholine (ACh) in randomly distributed circles across the tissue. Different circle sizes of ACh and fibrosis geometries were considered, accounting for both uniform diffuse and non-uniform diffuse fibrosis. Computational simulations were performed, from which unipolar EGMs were computed in a 16 × 1 6 electrode mesh. Different distances of the electrodes to the tissue (0.5, 1, and 2 mm) and noise levels with signal-to-noise ratio (SNR) values of 0, 5, 10, 15, and 20 dB were tested. The amplitude of the atrial EGM repolarization wave was found to be representative of the presence or absence of ACh release sites, with larger positive amplitudes indicating that the electrode was placed over an ACh region. Statistical analysis was performed to identify the optimal thresholds for the identification of ACh sites. In all non-AF, PxAF, and PsAF tissues, the repolarization amplitude rendered successful identification. The algorithm performed better in the absence of fibrosis or when fibrosis was uniformly diffuse, with a mean accuracy of 0.94 in contrast with a mean accuracy of 0.89 for non-uniform diffuse fibrotic cases. The algorithm was robust against noise and worked for the tested ranges of electrode-to-tissue distance. In conclusion, the results from this study support the feasibility to locate atrial parasympathetic innervation sites from the amplitude of repolarization wave.

Abstract 4307: New Insights into Surgical Atrial Fibrillation Ablation Therapy: Initial Experience with a Novel Permanently Implantable Heart Rhythm Monitor Device

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Thorsten Hanke ◽  
Antje Karlub ◽  
Efstratios Charitos ◽  
Axel Hagemann ◽  
Bernhard Graf ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Heart Rhythm ◽  
Holter Monitoring ◽  
Ecg Monitoring ◽  
Time Intervals ◽  
Ablation Therapy ◽  
Implantable Monitor ◽  
Monitor Device ◽  
Rhythm Monitoring ◽  
Af Recurrence

Introduction: Surgical atrial fibrillation (AF) therapy is gaining widespread acceptance among cardiothoracic surgeons. However, assessment of therapy success is until now solely based on short time -“snapshot”-rhythm surveillance often at irregular time intervals. In order to evaluate the ablation’s success we intraindividually compared two different types of follow-up strategies: conventional 24h-Holter monitoring and direct long time rhythm surveillance achieved by a new implantable monitor device (IRMD). Methods: 20 cardiac surgical patients (male 16, mean age 69±9y) with a mean AF of 30±48m (paroxysmal n=7, persistent n=9, long standing persistent n=4) were treated intraoperatively with epicardial high intensity focus ultrasound (HIFU) ablation (+CABG n=10, +AVR n=5, +AVR/CABG n=2, +valve preserving ascending aorta replacement n=2, +endoaneurymoraphy n=1, lone atrial fibrillation n=1). Postoperative heart rhythm monitoring was accomplished in all patients with a 24h-Holter-monitor at prescheduled time intervals and additionally with a new implantable monitor device (Reveal XT, Medtronic®, MN, USA). A more than 0.5% of “time in AF” as reported by the IRMD was considered as recurrence of AF. Telemetry of the IRMD was performed simultaneously after completion of 24h-Holter monitoring. Results: During a mean FU of 8.7±1.4m a total of 29 24 h-Holter-monitors were obtained. Sinus rhythm was documented in 21, the IMRD however revealed AF recurrence in 11 of these cases. Thus, conventional 24 h ECG monitoring failed to identify AF recurrence in 59% of cases (p<0.027). Success rate after surgical ablation therapy (defined as freedom from AF recurrence of more than 0.5% of observational period) was 72% with 24h Holter monitoring, but only 35% using continuous ECG monitoring with IRMD. Conclusion: In order to evaluate better “real life” outcomes after atrial fibrillation ablation therapy, long term continuous heart rhythm surveillance instead of -“snapshot” - heart rhythm monitoring is mandatory. This is particularly important for the decision to alter medical therapies, e.g. oral anticoagulation or antiarrhythmic treatment.

MO749CATHETER ABLATION FOR ATRIAL FIBRILLATION IN PATIENTS WITH CHRONIC KIDNEY DISEASE AND ON DIALYSIS - A META-ANALYSIS

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Isaac Chung ◽  
Yasir Khan ◽  
Rao Kondapally ◽  
Manav Sohal ◽  
Debasish Banerjee
Keyword(s):  
Atrial Fibrillation ◽  
Chronic Kidney Disease ◽  
Catheter Ablation ◽  
Kidney Disease ◽  
Meta Analysis ◽  
Recurrence Rates ◽  
Ablation Therapy ◽  
Abnormal Metabolism ◽  
Af Recurrence

Abstract Background and Aims Atrial fibrillation (AF) is common in chronic kidney disease (CKD) patients and is difficult to treat with antiarrhythmics and anticoagulants due to abnormal metabolism and increased side effects. Catheter ablation if successful may be a safer alternative. This review evaluates the efficacy of catheter ablation therapy in CKD and haemodialysis (HD) patients. Method MEDLINE and Embase databases were searched with the following search terms: “(atrial fibrillation AND (chronic kidney disease OR renal failure OR renal function OR dialysis) AND ablation)” for journal articles of any language until December 2020. Two authors abstracted the data independently. Risk ratios were derived using random-effects meta-analysis. Results Of the initially identified 520 studies, 5 and 3 observational studies on CKD and HD patients respectively were found reporting AF recurrence rates. During a mean (SD) follow-up of 25.5 (9.8) months, CKD patients had a higher risk of AF recurrence compared to patients without CKD (RR 2.34, 95% CI 1.36-4.02, p&lt;0.01). The heterogenicity test showed there were significant differences between individual studies (I2 = 91%, 95% CI 82.2%-95.6%, p&lt;0.01). In a mean (SD) follow-up of 40.3 (20.8) months, HD patients may be at a higher risk of AF recurrence compared to healthy non-dialysis AF patients (RR 1.21, 95% CI 0.64-2.30, p=0.55). Heterogeneity analysis showed the studies were heterogeneous (I2 92.3%, 95% CI 80.8%-96.9%, p &lt;0.01). Conclusion Our meta-analysis suggests patients with CKD and patients on HD are more likely to have AF recurrences after catheter ablation compared to AF patients who are otherwise healthy. However, more robust evidence from randomized controlled trials comparing catheter ablation and pharmaceutical rhythm therapy are urgently needed to guide therapy in this difficult to treat population.

The Efficacy of Anti-inflammatory Agents in the Prevention of Atrial Fibrillation Recurrences

2020 ◽  
Vol 28 (1) ◽  
pp. 137-151
Author(s):  
Homa Nomani ◽  
Sara Saei ◽  
Thomas P. Johnston ◽  
Amirhossein Sahebkar ◽  
Amir Hooshang Mohammadpour
Keyword(s):  
Atrial Fibrillation ◽  
Clinical Trials ◽  
Therapeutic Option ◽  
General Rule ◽  
Promising Candidate ◽  
Term Basis ◽  
Inflammatory Drugs ◽  
Anti Inflammatory ◽  
Meta Analyses ◽  
Af Recurrence

: Several studies have indicated an association between inflammation and the recurrence of Atrial Fibrillation (AF), especially after ablation, which is a therapeutic option leading to local inflammation. On the other hand, each AF can lead to another AF, as a general rule. Thus, preventing recurrences of AF is extremely important for patient outcomes. In this paper, we attempted to review the effect of medicinal agents with anti-inflammatory properties on the prevention of AF recurrence. There are several randomized controlled trials (RCTs) and meta-analyses on the prevention of AF recurrence using agents with anti-inflammatory properties, which include steroids, colchicine, statins, and n-3 fatty acids (n-3 FA). Clinical trials evaluating the efficacy of anti-inflammatory drugs in preventing the recurrence of AF led to inconsistent results for corticosteroids, statins and n-3 FAs. These results may be related to the fact that inflammation is not the only factor responsible for triggering recurrences of AF. For example, the presence of structural, mechanical and electrical remodeling could potentially be the most important factors that trigger recurrences of AF but these factors have not been addressed in most of the reported studies. Therefore, future clinical trials are needed to compare the efficacy of anti-inflammatory drugs in AF patients with, or without other factors. For colchicine, a potent anti-inflammatory drug, there are limited studies. However, all the studies investigating colchicine in the context of AF were consistent and promising, especially when colchicine was used on a short-term basis following ablation in patients with paroxysmal AF. Therefore, colchicine could be a promising candidate for further clinical studies involving recurrent AF.

Long-term results of thoracoscopic ablation of paroxysmal atrial fibrillation: is the glass half full or half empty?

2021 ◽  
Author(s):  
Igor Belluschi ◽  
Elisabetta Lapenna ◽  
Davide Carino ◽  
Cinzia Trumello ◽  
Manuela Cireddu ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Confidence Interval ◽  
Paroxysmal Atrial Fibrillation ◽  
Left Ventricular ◽  
Class I ◽  
Long Term Results ◽  
Left Ventricular Ejection ◽  
Af Recurrence

Abstract OBJECTIVES Previous series showed the outcomes of thoracoscopic ablation of stand-alone symptomatic paroxysmal atrial fibrillation (AF) for up to 7 years of follow-up. The goal of this study was to assess the long-term durability of surgical pulmonary vein isolation (PVI) beyond 7 years. METHODS Fifty consecutive patients {mean age 55 [standard deviation (SD): 11.2] years, previous catheter ablation in 56%, left ventricular ejection fraction 60% (SD: 4.6), left atrium volume 65 ml (SD: 17)} with stand-alone symptomatic paroxysmal AF underwent PVI through bilateral thoracoscopy ablation between 2005 and 2014. The CHA2DS2-VASc score was ≥2 in 12 patients (24%). RESULTS No hospital deaths occurred. At hospital discharge all patients but 1 (2%) were in sinus rhythm (SR). Follow-up was 100% complete [mean 8.4 years (SD: 2.3), max 15]. The 8-year cumulative incidence function of AF recurrence, with death as a competing risk, on or off class I/III antiarrhythmic drugs (AADs)/electrocardioversion/re-transcatheter ablation (TCA) was 20% (SD: 5; 95% confidence interval: 10, 32); and off class I/III AADs/electrocardioversion/re-TCA was 52% (SD: 7; 95% confidence interval: 0.83, 8.02). At 8 years, the predicted prevalence of patients in SR was 87% and 53% were off class I/III AADs/electrocardioversion/re-TCA. The recurrent arrhythmia was AF in all patients except 2, who had atypical atrial flutter (4%). No predictors of AF recurrence were identified. At the last follow-up, 76% of the patients showed European Heart Rhythm Association class I. No strokes or thromboembolic events were documented and 76% of the subjects were off anticoagulation therapy. CONCLUSIONS Despite a considerable AF recurrence rate, our single-centre, long-term outcome of surgical PVI showed encouraging data, with the majority of patients remaining in SR, although many of them were on antiarrhythmic therapy.

Does Motion Perception Follow Weber's Law?

Perception ◽  
1995 ◽  
Vol 24 (4) ◽  
pp. 363-372 ◽  
Author(s):  
Johannes M Zanker
Keyword(s):  
Motion Perception ◽  
Stimulus Intensity ◽  
Signal To Noise Ratio ◽  
Weber’S Law ◽  
Noise Levels ◽  
Signal To Noise ◽  
Weber's Law ◽  
The Absolute ◽  
Noise Ratio ◽  
Random Dot Patterns

The subjective strength of a percept often depends on the stimulus intensity in a nonlinear way. Such coding is often reflected by the observation that the just-noticeable difference between two stimulus intensities (JND) is proportional to the absolute stimulus intensity. This behaviour, which is usually referred to as Weber's Law, can be interpreted as a compressive nonlinearity extending the operating range of a sensory system. When the noise superimposed on a motion stimulus is increased along a logarithmic scale (in order to provide linear steps in subjective difference) in motion-coherency measurements, observers often report that the subjective differences between the various noise levels increase together with the absolute level. This observation could indicate a deviation from Weber's Law for variation of motion strength as obtained by changing the signal-to-noise ratio in random-dot kinematograms. Thus JNDs were measured for the superposition of uncorrelated random-dot patterns on static random-dot patterns and three types of motion stimuli realised as random-dot kinematograms, namely large-field and object ‘Fourier’ motion (all or a group of dots move coherently), ‘drift-balanced’ motion (a travelling region of static dots), and paradoxical ‘theta’ motion (the dots on the surface of an object move in opposite direction to the object itself). For all classes of stimuli, the JNDs when expressed as differences in signal-to-noise ratio turned out to increase with the signal-to-noise ratio, whereas the JNDs given as percentage of superimposed noise appear to be similar for all tested noise levels. Thus motion perception is in accordance with Weber's Law when the signal-to-noise ratio is regarded as stimulus intensity, which in turn appears to be coded in a nonlinear fashion. In general the Weber fractions are very large, indicating a poor differential sensitivity in signal-to-noise measurements.

Role of the Ambulatory Assessed Apnea-Hypopnea Index for Predicting Recurring Atrial Fibrillation After Ablation Therapy

2021 ◽  
Author(s):  
Teresa Trenkwalder ◽  
Christian Grebmer ◽  
Madeleine Tydecks ◽  
Patrick Blažek ◽  
Marc Kottmaier ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Apnea Hypopnea Index ◽  
Ablation Therapy

Predictors of recurrence after durable pulmonary vein isolation for paroxysmal atrial fibrillation

EP Europace ◽  
2020 ◽  
Author(s):  
Michelle Lycke ◽  
Maria Kyriakopoulou ◽  
Milad El Haddad ◽  
Jean-Yves Wielandts ◽  
Gabriela Hilfiker ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Vein ◽  
Pulmonary Vein Isolation ◽  
Paroxysmal Atrial Fibrillation ◽  
Prospective Trial ◽  
High Rate ◽  
Binary Logistic Regression Analysis ◽  
Ablation Time ◽  
Increased Risk ◽  
Af Recurrence

Abstract Aims Catheter ablation of paroxysmal atrial fibrillation (AF) reduces AF recurrence, AF burden, and improves quality of life. Data on clinical and procedural predictors of arrhythmia recurrence are scarce and are flawed by the high rate of pulmonary vein reconnection evidenced during repeat procedures after pulmonary vein isolation (PVI). In this study, we identified clinical and procedural predictors for AF recurrence 1 year after CLOSE-guided PVI, as this strategy has been associated with an increased PVI durability. Methods and results Patients with paroxysmal AF, who received CLOSE-guided PVI and who participated in a prospective trial in our centre, were included in this study. Uni- and multivariate models were plotted to find clinical and procedural predictors for AF recurrence within 1 year. Three hundred twenty-five patients with a mean age of 63 years (CHA2DS2VASc 1 [1–3], left atrium diameter 41 ± 6 mm) were included. About 60.9% were male individuals. After 1 year, AF recurrence occurred in 10.5% of patients. In a binary logistic regression analysis, the diagnosis-to-ablation time (DAT) was found to be the strongest predictor of AF recurrence (P = 0.011). Diagnosis-to-ablation time ≥1 year was associated with a nearly two-fold increased risk for developing AF recurrence. Conclusion The DAT is the most important predictor of arrhythmia recurrence in low-risk patients treated with durable pulmonary vein isolation for paroxysmal AF. Whether reducing the DAT could improve long-term outcomes should be investigated in another trial.

Ablation Therapy for Atrial Fibrillation: Implications for the Anesthesiologist

2015 ◽  
Vol 29 (5) ◽  
pp. 1341-1356 ◽  
Author(s):  
Himani V. Bhatt ◽  
Georgios Syros ◽  
Michael Greco ◽  
Marc Miller ◽  
Gregory W. Fischer
Keyword(s):  
Atrial Fibrillation ◽  
Ablation Therapy

Abstract P172: Circulating Heat Shock Protein 70 and Antiheat Shock Protein 70 Antibodies in Atrial Fibrillation: Relation with Atrial Fibrillation Type and Response to Catheter Ablation

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Jelena Kornej ◽  
Claudia Reinhardt ◽  
Jedrzej Kosiuk ◽  
Arash Arya ◽  
Gerhard Hindricks ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Regression Analysis ◽  
Catheter Ablation ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Recurrence Rates ◽  
Multivariable Regression Analysis ◽  
Multivariable Regression ◽  
Af Recurrence

Background: HSP and anti-HSP antibodies have been associated with AF development and progression. This study investigated the possible association between circulating heat shock protein 70 (HSP70) and anti-HSP70 antibodies as well their changes and rhythm outcome after atrial fibrillation (AF) catheter ablation. Methods: In 67 patients with AF (59±11 years, 66 % male, 66 % lone AF) undergoing catheter ablation, circulating HSP70 and anti-HSP70 antibodies levels were quantified before and 6 months after catheter ablation. Serial 7-day Holter ECGs were used to detect AF recurrences. Results: At baseline, HSP70 was detectable in 14 patients (21 %), but there was no correlation between clinical or echocardiographic variables and the presence or the level of HSP70. Patients with paroxysmal AF (n=39) showed lower anti-HSP70 antibodies (median 43, IQR 28 - 62 µg/ml) than patients with persistent AF (n=28; 53, 41 - 85 µg/ml, p=.035). Using multivariable regression analysis, AF type was the only variable associated with anti-HSP70 antibodies (Beta=.342, p=.008). At 6 months, HSP70 was present in 27 patients (41 %, p<.001 vs. baseline) with an overall increase (median 0, IQR 0 - 0 vs. 0, 0 - 0.09 ng/ml, p=.029). Similarly, there was an increase of anti-HSP70 antibodies (48, 36 - 72 vs. 57, 43 - 87 µg/ml, p<.001). AF recurrence rates were higher in patients with HSP70 increase >0.025 ng/ml (32 vs. 11 %, p=.038) or anti-HSP70 antibodies increase >2.5 µg/ml (26 vs. 4 %, p=.033). Conclusion: HSP70 and anti-HSP70 antibodies may be involved in the progression of AF and AF recurrence after catheter ablation.

Abstract 13793: Role of Cardiac Autoantibodies for the Prediction of Recurrence Following Cryoballoon-based Lone Atrial Fibrillation Ablation

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Muhammed U Yalcin ◽  
Kadri M Gurses ◽  
Duygu Kocyigit ◽  
Sacit A Kesikli ◽  
Hikmet Yorgun ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Predictive Value ◽  
Cox Regression ◽  
Muscarinic Acetylcholine Receptor ◽  
Left Atrial Volume ◽  
Volume Index ◽  
Lone Atrial Fibrillation ◽  
Left Atrial Volume Index ◽  
One Year ◽  
Af Recurrence

Introduction: Recent evidence have suggested that autoantibodies may play an important role in the development of atrial fibrillation (AF). Predictive value of pre-procedural autoantibodies against beta-1 adrenergic receptor (anti-β1-R) and M2-muscarinic acetylcholine receptor (anti-M2-R) for AF recurrence following cryoballoon-based pulmonary vein isolation (PVI) is still unclear. We aimed to determine the predictive value of pre-procedural anti-β1-R and anti-M2-R levels for AF recurrence in lone AF patients following cryoballoon-based PVI. METHODS: 80 patients (mean age 54.25±7.7 years; 40% males) with lone AF who underwent cryoballoon-based PVI were included in the study. Pre-procedural anti-M2-R and anti-β1-R levels were measured with ELISA. RESULTS: At one-year follow-up after ablation, late AF recurrence was observed in 17 (21.25%) patients. In the Cox regression model including number of antiarrhythmic drugs, early AF recurrence, anti-β1-R levels >159.88 ng/mL, anti-M2-R levels >277.65 ng/mL, AF duration and left atrial volume index; only anti-β1-R levels >159.88 ng/mL (HR: 4.281, p=0.039) and anti-M2-R levels >277.65 ng/mL (HR: 4.313, p=0.030) were found to be independent predictors of late AF recurrence. Anti-β1-R level >159.88 ng/mL was shown to predict late AF recurrence with a sensitivity of 70.59% and specificity of 90.48%. A cut-off value of 277.65 ng/mL for anti-M2-R level predicted AF recurrence with a sensitivity of 70.59% and specificity of 95.24%. CONCLUSION: Pre-procedural serum anti-β1-R and anti-M2-R levels are independent predictors of late AF recurrence following cryoballoon-based PVI in lone AF patients. Detection of pre-procedural anti-β1-R and anti-M2-R levels may serve as a novel method for determination of lone AF patients who may not benefit from cryoballoon-based PVI.

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