Electrical atrial fibrillation induction affects the characteristics of induced arrhythmia

Róka, Attila; Tóth, Eszter; Szilágyi, Szabolcs; Merkely, Béla

doi:10.1016/j.jelectrocard.2007.05.015

Cited by 4 publications

(6 citation statements)

References 26 publications

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“…2 However, persistent AF in animal models has not been rigorously defined, which may have led to inconsistencies in the results reported for models versus patients with persistent AF. 8, 10 Fast atrial pacing is a common approach to induce AF in animal models. Yet, some studies use the term “persistent AF” for those episodes in which the arrhythmia sustains in the short term (<7 days) in the absence of pacing, 8, 10 either for cardioversion attempts or electrophysiological measurements.…”

Section: Discussionmentioning

confidence: 99%

“…9 However, those studies were somehow limited by the fact that they addressed persistent AF of relatively short 8 or unconfirmed, duration. 10, 11 In addition, no information was provided on the spatial distribution of the atrial activation rates. Here we aimed at filling those gaps by studying in-vivo the time-course of the changes in DF values and the evolution of the left-to-right DF dispersion during the transition from paroxysmal to persistent AF.…”

Section: Introductionmentioning

confidence: 99%

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Long-Term Frequency Gradients During Persistent Atrial Fibrillation in Sheep Are Associated With Stable Sources in the Left Atrium

Filgueiras-Rama

Price

Martins

et al. 2012

Circ: Arrhythmia and Electrophysiology

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Background Dominant frequencies (DFs) of activation are higher in the atria of patients with persistent than paroxysmal atrial fibrillation (AF) and left-to-right atrial (LA-to-RA) DF gradients have been identified in both. However, whether such gradients are maintained as long-term persistent AF is established remains unexplored. We aimed at determining in-vivo the time-course in atrial DF values from paroxysmal to persistent AF in sheep, and test the hypothesis that a LA-to-RA DF difference is associated with LA drivers in persistent AF. Methods and Results AF was induced using RA tachypacing (N=8). Electrograms were obtained weekly from a RA lead and a loop recorder (ILR) implanted near the LA. DFs were determined for 5-sec-long electrograms (QRST subtracted) during AF in-vivo and in ex-vivo optical mapping. Underlying structural changes were compared to weight-matched controls (N=4). Following the first AF episode, DF increased gradually over a 2-week period (7±0.21 to 9.92±0.31 Hz, N=6, p<0.05). During 9–24 weeks of AF the DF values on the ILR were higher than the RA (10.6±0.08 vs. 9.3±0.1 Hz, respectively; N=7, p<0.0001). Subsequent optical mapping confirmed a DF gradient from posterior LA-to-RA (9.1±1.0 to 6.9±0.9 Hz. p<0.05) and demonstrated patterns of activation compatible with drifting rotors in the posterior LA (PLA). Persistent AF sheep showed significant enlargement of the PLA compared to controls. Conclusions In the sheep transition from paroxysmal to persistent AF shows continuous LA-to-RA DF gradients in-vivo together with enlargement of the PLA, which harbors the highest frequency domains and patterns of activation compatible with drifting rotors.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Long-Term Frequency Gradients During Persistent Atrial Fibrillation in Sheep Are Associated With Stable Sources in the Left Atrium

Filgueiras-Rama

Price

Martins

et al. 2012

Circ: Arrhythmia and Electrophysiology

View full text Add to dashboard Cite

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“…The ECG pattern of the AF (i.e. the absence of P waves, disorganized electrical activity in their place, and irregular R-R intervals due to irregular conduction iimparted to the ventricles) induced intraoperatively in our experimental setting was similar to that found clinically in patients [19]–[21]. This set-up for arrhythmia generation was chosen for motion control and tracking purposes only and not for the functional aspect of rhythm disturbances.…”

Section: Methodsmentioning

confidence: 86%

“…The method of inducing atrial fibrillation (AF) by electrically stimulating right atrium has been used in the literature for easy and reliable modeling of AF [19]–[21]. The AF was induced by stimulating the right atrium via two electrodes connected to an Electric Transformer with 2.5V AC @60 Hz.…”

Section: Methodsmentioning

confidence: 99%

Towards Active Tracking of Beating Heart Motion in the Presence of Arrhythmia for Robotic Assisted Beating Heart Surgery

et al. 2014

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In robotic assisted beating heart surgery, the control architecture for heart motion tracking has stringent requirements in terms of bandwidth of the motion that needs to be tracked. In order to achieve sufficient tracking accuracy, feed-forward control algorithms, which rely on estimations of upcoming heart motion, have been proposed in the literature. However, performance of these feed-forward motion control algorithms under heart rhythm variations is an important concern. In their past work, the authors have demonstrated the effectiveness of a receding horizon model predictive control-based algorithm, which used generalized adaptive predictors, under constant and slowly varying heart rate conditions. This paper extends these studies to the case when the heart motion statistics change abruptly and significantly, such as during arrhythmias. A feasibility study is carried out to assess the motion tracking capabilities of the adaptive algorithms in the occurrence of arrhythmia during beating heart surgery. Specifically, the tracking performance of the algorithms is evaluated on prerecorded motion data, which is collected in vivo and includes heart rhythm irregularities. The algorithms are tested using both simulations and bench experiments on a three degree-of-freedom robotic test bed. They are also compared with a position-plus-derivative controller as well as a receding horizon model predictive controller that employs an extended Kalman filter algorithm for predicting future heart motion.

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“…Recordings from 4 dogs used in our previous study were analyzed [8]. Bipolar epicardial electrodes were applied to the right and left atrial appendages after thoracotomy, atrial fibrillation was induced with 4.5 V direct current and 50 Hz high-frequency stimulation.…”

Section: Intracardiac Electrogram Recordingmentioning

confidence: 99%

Development and validation of a model of atrioventricular conduction in atrial fibrillation based on junctional intracardiac electrograms

Róka

Merkely

2008

2008 Computers in Cardiology

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Ventricular activation in atrial fibrillation (AF) is irregular. Our aim was to develop and validate a new model of atrioventricular conduction (AVC) in AF.Intracardiac electrograms (IEGM) were recorded in 4 dogs in AF near the AV junction. Four timing intervals with 8 parameters were used to create a model of AVC: absolute and relative refractory periods, slow and normal conduction times. 26406 RR intervals were used to calculate and 2142 intervals to validate the prediction accuracy.Using the optimal combination of the parameters the RR interval prediction had an average error of 99±80 ms, validation showed a value of 99±77 ms.In conclusion, prediction of RR intervals in AF is possible using IEGM near the AV junction.

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Electrical atrial fibrillation induction affects the characteristics of induced arrhythmia

Cited by 4 publications

References 26 publications

Long-Term Frequency Gradients During Persistent Atrial Fibrillation in Sheep Are Associated With Stable Sources in the Left Atrium

Long-Term Frequency Gradients During Persistent Atrial Fibrillation in Sheep Are Associated With Stable Sources in the Left Atrium

Towards Active Tracking of Beating Heart Motion in the Presence of Arrhythmia for Robotic Assisted Beating Heart Surgery

Development and validation of a model of atrioventricular conduction in atrial fibrillation based on junctional intracardiac electrograms

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