scholarly journals Regions of Highly Recurrent Electrogram Morphology at Sites of Low Cycle Length Accurately Reflect Arrhythmogenic Substrate for Atrial Fibrillation – Implications For a New, Mechanism Guided Therapeutic Approach for Atrial Fibrillation

2020 ◽  
Author(s):  
Shin Yoo ◽  
Markus Rottmann ◽  
Jason Ng ◽  
David Johnson ◽  
Bassel Shanab ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Cycle Length ◽  
Dominant Frequency ◽  
Nerve Fibers ◽  
Atrial Pacing ◽  
Parasympathetic Innervation ◽  
Complexity Measures ◽  
Parasympathetic Nerve ◽  
Arrhythmogenic Substrate ◽  
Before And After

ABSTRACTBackgroundAlthough atrial electrograms (EGMs) are thought to reflect pathophysiological substrate for atrial fibrillation (AF), it is not known which electrograms are suitable targets during AF ablation. We hypothesized that electrogram morphology recurrence (EMR) better reflects arrhythmogenic AF substrate than traditional frequency and complexity measures of AF. In a canine rapid atrial pacing (RAP) model of AF, we assessed the relationship between EMR and traditional AF electrogram measures, rotational activity in the atria, fibrosis, myofiber orientation and parasympathetic innervation.MethodsPersistent AF was induced in 13 dogs by RAP for 6-8 weeks. High-density epicardial mapping (117 electrodes) was performed in six atrial sub-regions. EMR measures Recurrence percentage (Rec%) and cycle length of the most frequent electrogram morphology (CLR), Fractionated Interval (FI), Organization Index (OI), Dominant Frequency (DF) and Shannon’s Entropy (ShEn) were analyzed before and after atropine administration. Myocyte fiber orientation, amount of fibrosis and spatial distribution of parasympathetic nerve fibers were quantified.ResultsRec% was greatest in the appendages, and CLR was lowest in the posterior left atrium. Rec%/CLR correlated with FI, OI and the complexity measure ShEn, but not with DF. All electrogram measures were poorly correlated with fibrosis and myofiber anisotropy. Rec% correlated closely with stability of rotational activity. Unlike other measures, Rec% correlated closely with spatial heterogeneity of parasympathetic nerve fibers; this was reflected in CLR response to atropine.ConclusionEMR correlates closely with stability of rotational activity and with the pattern of atrial parasympathetic innervation. CLR may therefore be a viable therapeutic target in persistent AF.

Abstract 4104: Organization of Atrial Signals is Critical Prior to Cardioversion of Atrial Fibrillation with Intravenous Flecainide: Insight from Spectral Analysis of Intracardiac Electrograms

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Jiun Tuan ◽  
Suman Kundu ◽  
Mohamed Jeilan ◽  
Faizel Osman ◽  
Rajkumar Mantravadi ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Spectral Analysis ◽  
Catheter Ablation ◽  
Cycle Length ◽  
Dominant Frequency ◽  
Relative Increase ◽  
Significant Difference ◽  
Before And After ◽  
Atrial Activation ◽  
Relative Change

Introduction & Hypothesis: Studies in catheter ablation of atrial fibrillation (AF) show that an increase in cycle length (CL) and higher organization index (OI) is associated with termination of AF. We hypothesize that similar changes can be seen in chemical cardioversion with Flecainide Methods: Patients who were still in AF at the end of catheter ablation for AF were given intravenous flecainide. OI and dominant frequency (DF) were obtained by Fast Fourier Transform of coronary sinus electrograms over 10s in AF, before and after flecainide infusion. Mean CL was also calculated. Results: 28 patients were identified (18 paroxysmal AF and 10 persistent AF). 8 cardioverted to sinus rhythm (SR) with flecainide. In all patients, mean CL increased from 211 ± 44 ms to 321 ± 85 ms (p <0.001). Mean DF decreased from 5.2 ± 1.03 Hz to 3.6 ± 1.04 Hz (p <0.001). Mean OI was 0.33 ± 0.13 before and 0.32 ± 0.11 after flecainide (p = 0.90). Comparing patients who cardioverted to SR with those who did not, OI post-flecainide was 0.41 ± 0.12 vs 0.29 ± 0.10 (p=0.013) and relative change in OI was 29 ± 33% vs −3.9 ± 27% (p=0.016) respectively. No significant difference was noted in the change in CL and DF in the 2 groups. Logistic regression showed that a greater relative increase in OI (p=0.04), a higher OI post-flecainide (p=0.03) and SR at start of procedure (p=0.03) are independently associated with cardioversion to SR with flecainide. Conclusion: Increase in OI, independent of changes to the CL and DF, appears critical to AF termination with flecainide. The increase in OI may reflect an increase in size and reduction in the number of re-entrant circuits, which together with slowing of atrial activation, result in return to SR.

The Relationship Between Electrogram Cycle Length and Dominant Frequency in Patients with Persistent Atrial Fibrillation

2009 ◽  
Vol 20 (12) ◽  
pp. 1336-1342 ◽  
Author(s):  
SHELDON M. SINGH ◽  
E. KEVIN HEIST ◽  
JACOB S. KORUTH ◽  
CONOR D. BARRETT ◽  
JEREMY N. RUSKIN ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Cycle Length ◽  
Persistent Atrial Fibrillation ◽  
Dominant Frequency ◽  
The Relationship

scholarly journals Panoramic Endocardial Optical Mapping Demonstrates Serial Rotors Acceleration and Increasing Complexity of Activity During Onset of Cholinergic Atrial Fibrillation

2021 ◽  
Author(s):  
Óscar Salvador‐Montañés ◽  
Rafael J. Ramirez ◽  
Yoshio Takemoto ◽  
Steven R. Ennis ◽  
Daniel Garcia‐Iglesias ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Cycle Length ◽  
Optical Mapping ◽  
Dominant Frequency ◽  
Right Atrial ◽  
Mapping System ◽  
Left And Right ◽  
Initiation Stage ◽  
Mean Cycle ◽  
Onset Atrial Fibrillation

Background Activation during onset of atrial fibrillation is poorly understood. We aimed at developing a panoramic optical mapping system for the atria and test the hypothesis that sequential rotors underlie acceleration of atrial fibrillation during onset. Methods and Results Five sheep hearts were Langendorff perfused in the presence of 0.25 µmol/L carbachol. Novel optical system recorded activations simultaneously from the entire left and right atrial endocardial surfaces. Twenty sustained (>40 s) atrial fibrillation episodes were induced by a train and premature stimuli protocol. Movies obtained immediately (Initiation stage) and 30 s (Early Stabilization stage) after premature stimulus were analyzed. Serial rotor formation was observed in all sustained inductions and none in nonsustained inductions. In sustained episodes maximal dominant frequency increased from (mean±SD) 11.5±1.74 Hz during Initiation to 14.79±1.30 Hz at Early Stabilization ( P <0.0001) and stabilized thereafter. At rotor sites, mean cycle length (CL) during 10 prerotor activations increased every cycle by 0.53% ( P =0.0303) during Initiation and 0.34% ( P =0.0003) during Early Stabilization. In contrast, CLs at rotor sites showed abrupt decreases after the rotors appearances by a mean of 9.65% ( P <0.0001) during both stages. At Initiation, atria‐wide accelerations and decelerations during rotors showed a net acceleration result whereby post‐rotors atria‐wide minimal CL (CLmin) were 95.5±6.8% of the prerotor CLmin ( P =0.0042). In contrast, during Early Stabilization, there was no net acceleration in CLmin during accelerating rotors (prerotor=84.9±11.0% versus postrotor=85.8±10.8% of Initiation, P =0.4029). Levels of rotor drift distance and velocity correlated with atria‐wide acceleration. Nonrotor phase singularity points did not accelerate atria‐wide activation but multiplied during Initiation until Early Stabilization. Increasing number of singularity points, indicating increased complexity, correlated with atria‐wide CLmin reduction ( P <0.0001). Conclusions Novel panoramic optical mapping of the atria demonstrates shortening CL at rotor sites during cholinergic atrial fibrillation onset. Atrial fibrillation acceleration toward Early Stabilization correlates with the net result of atria‐wide accelerations during drifting rotors activity.

Frequency Analysis for Surface Electrocardiogram Of Atrial Fibrillation

2013 ◽  
Vol 64 (5) ◽  
Author(s):  
Anita Ahmad ◽  
Salinda Buyamin ◽  
Nurhamizah Senin
Keyword(s):  
Atrial Fibrillation ◽  
Positive Result ◽  
Frequency Analysis ◽  
Dominant Frequency ◽  
Ecg Signal ◽  
Preprocessing Method ◽  
Before And After ◽  
Electrocardiogram Ecg ◽  
Surface Electrocardiogram ◽  
Established Technique

This paper presents the behaviour of the dominant frequency of the electrocardiogram (ECG) signal for atrial fibrillation patients before and after preprocessing. The preprocessing method (QRST subtraction) is useful to obtain a clean atrial signal before performing frequency analysis. The QRST subtraction was performed and the dominant frequency before and after QRST subtraction was compared. This study demonstrates a positive result with this technique in comparison with another established technique. 

Abstract 17454: The Effect of Catheter Ablation on Coronary Sinus Cycle Length in Persistent Atrial Fibrillation

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Ghaith Zaatari ◽  
Jorge Bohorquez ◽  
Raul Mitrani ◽  
Jason Ng ◽  
Justin Ng ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Coronary Sinus ◽  
Cycle Length ◽  
Persistent Atrial Fibrillation ◽  
Posterior Wall ◽  
Quality Signals ◽  
Before And After ◽  
Ventricular Activation ◽  
Ablation Success

Background: While pulmonary vein isolation (PVI) for treatment of persistent atrial fibrillation (PeAF) is successful in approximately 50%, acute termination of PeAF is rarely observed. Prolongation of cycle length (CL) by 10% is often utilized as an indicator of successful catheter ablation (CA). Objective: To evaluate coronary sinus (CS) cycle length (CL) before and after CA for PeAF. Methods: CA for PeAF was performed in 31 patients (24males, age 63±9 yrs, CHA2DS2-VASc 2.3±1.7, LVEF 49±10%) with PVI, with 4 (13%) also having posterior wall isolation. A multielectrode catheter was placed in the CS and maintained throughout the procedure. CS electrograms were recorded for 10 seconds prior to CA and after completion of CA. No patient reverted to sinus rhythm during CA. CS CL was determined using customized software for activation detection and verified visually, excluding ventricular activation and low quality signals (n=3). The shortest CL among the recording electrodes was used for analysis. Results: CS CL pre- and post-CA were 182.4±23.0 and 191.6± 29.9 ms (p= 0.04) with change from baseline of 5.4±12.7%. The figure shows the histogram for change in CS CL from baseline. Only 7/28 (25%) of patients had CS CL prolongation >10%. Of ten patients who were free of AF off anti-arrhythmic drugs at 1 year, CS CL increased 4.0±6.1%; 2/10 had CS CL prolongation >10%. Of 6 patients with recurrent AF, CS CL increased 13.8±20.7%; 4/6 had CS CL prolongation >10%. Conclusion: Our data demonstrate that CS CL prolongation >10% is not a useful marker of outcomes in patients undergoing catheter ablation for PeAF. This highlights the need to identify other indicators of acute ablation success.

scholarly journals Heartbeat Cycle Length Detection by a Ballistocardiographic Sensor in Atrial Fibrillation and Sinus Rhythm

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Matthias Daniel Zink ◽  
Christoph Brüser ◽  
Patrick Winnersbach ◽  
Andreas Napp ◽  
Steffen Leonhardt ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Heart Rate ◽  
Sinus Rhythm ◽  
Quality Index ◽  
Cycle Length ◽  
Heart Rate Monitoring ◽  
Mechanical Vibrations ◽  
Before And After ◽  
Registration Number ◽  
Novel Algorithm

Background.Heart rate monitoring is especially interesting in patients with atrial fibrillation (AF) and is routinely performed by ECG. A ballistocardiography (BCG) foil is an unobtrusive sensor for mechanical vibrations. We tested the correlation of heartbeat cycle length detection by a novel algorithm for a BCG foil to an ECG in AF and sinus rhythm (SR).Methods.In 22 patients we obtained BCG and synchronized ECG recordings before and after cardioversion and examined the correlation between heartbeat characteristics.Results.We analyzed a total of 4317 heartbeats during AF and 2445 during SR with a correlation between ECG and BCG during AF ofr=0.70(95% CI 0.68–0.71,P<0.0001) andr=0.75(95% CI 0.73–0.77,P<0.0001) during SR. By adding a quality index, artifacts could be reduced and the correlation increased for AF to 0.76 (95% CI 0.74–0.77,P<0.0001,n=3468) and for SR to 0.85 (95% CI 0.83–0.86,P<0.0001,n=2176).Conclusion.Heartbeat cycle length measurement by our novel algorithm for BCG foil is feasible during SR and AF, offering new possibilities of unobtrusive heart rate monitoring. This trial is registered with IRB registration number EK205/11. This trial is registered with clinical trials registration numberNCT01779674.

Optimal ventricular rate slowing during atrial fibrillation by feedback AV nodal-selective vagal stimulation

2002 ◽  
Vol 282 (3) ◽  
pp. H1102-H1110 ◽  
Author(s):  
Youhua Zhang ◽  
Kent A. Mowrey ◽  
Shaowei Zhuang ◽  
Don W. Wallick ◽  
Zoran B. Popović ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Vagal Stimulation ◽  
Atrioventricular Node ◽  
Nerve Fibers ◽  
Ventricular Rate ◽  
Parasympathetic Nerve ◽  
Beneficial Effects ◽  
Sinus Cycle Length ◽  
Precise Relationship ◽  
Feedback Algorithm

Although the beneficial effects of ventricular rate (VR) slowing during atrial fibrillation (AF) are axiomatic, the precise relationship between VR and hemodynamics has not been determined. We hypothesized that selective atrioventricular node (AVN) vagal stimulation (AVN-VS) by varying the nerve stimulation intensity could achieve precise graded slowing and permit evaluation of an optimal VR during AF. The aims of the present study were the following: 1) to develop a method for computerized vagally controlled VR slowing during AF, 2) to determine the hemodynamic changes at each level of VR slowing, and 3) to establish the optimal anterograde VR during AF. AVN-VS was delivered to the epicardial fat pad that projects parasympathetic nerve fibers to the AVN in 14 dogs. Four target average VR levels, corresponding to 75%, 100%, 125%, and 150% of the sinus cycle length (SCL), were achieved by computer feedback algorithm. VR slowing resulted in improved hemodynamics and polynomial fit analysis found an optimum for the cardiac output at VR slowing of 87% SCL. We conclude that this novel method can be used to maintain slow anterograde conduction with best hemodynamics during AF.

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