scholarly journals Characterization of fibrillatory rhythms by ensemble vector directional analysis

2003 ◽  
Vol 285 (4) ◽  
pp. H1705-H1719 ◽  
Author(s):  
Alan Kadish ◽  
David Johnson ◽  
Willie Choe ◽  
Jeffrey Goldberger ◽  
George Horvath
Keyword(s):  
Atrial Fibrillation ◽  
Ventricular Fibrillation ◽  
Objective Assessment ◽  
Atrial Pacing ◽  
Activation Patterns ◽  
Standard Mapping ◽  
Vector Index ◽  
Mapping Techniques ◽  
Different Characteristics ◽  
Vector Mapping

Recent studies have demonstrated that fibrillatory rhythms are not random phenomena but have definable patterns. However, standard mapping techniques may have limitations in their ability to identify the organization of fibrillation. The purpose of this study was to develop and apply a method, “ensemble vector mapping,” for characterizing the spatiotemporal organization of fibrillation. Ventricular fibrillation was induced by burst pacing in normal mongrel dogs. In a separate protocol, atrial fibrillation was induced by epicardial aconitine application. Epicardial electrograms were recorded from a 112-electrode plaque array using a computerized mapping system. Vectors were created by summing orthogonal bipolar electrograms. The magnitude of the vectors was transformed using a logarithmic function, integrated over time, and normalized for local electrogram amplitude to produce an “ensemble vector” index whose magnitude is high when beat-to-beat activation direction is consistent and low when activation direction is variable. The mean index was 137 ± 36 mV/s during ventricular pacing at a cycle length of 300 ms but only 39 ± 23 mV/s during ventricular fibrillation ( P < 0.001). The ensemble vector index was also lower during atrial fibrillation (60 ± 54 mV/s) than during atrial pacing (115 ± 27 mV/s, P < 0.01 vs. atrial fibrillation) but not as low as during ventricular fibrillation ( P < 0.05, atrial vs. ventricular fibrillation). The index was also capable of distinguishing atrial tachycardia from atrial fibrillation. Ensemble vector mapping produces an objective assessment of the consistency of myocardial activation during fibrillation. The consistency of activation direction differs in different models of fibrillation and is higher during atrial than ventricular fibrillation. This technique has the potential to rapidly characterize repetitive activation patterns in fibrillatory rhythms and may help distinguish among different characteristics of fibrillatory rhythms.

Abstract 15840: Electrogram Morphology Recurrence Analysis Identifies Areas of Consistent Activation Directions and Rotor Activity in a Rapid Atrial Pacing Model of Atrial Fibrillation

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
David Gordon ◽  
Rishi Arora ◽  
Gary L Aistrup ◽  
Jeffrey J Goldberger ◽  
Jason Ng
Keyword(s):  
Atrial Fibrillation ◽  
Right Atrial ◽  
Mapping Technique ◽  
Atrial Pacing ◽  
Average Value ◽  
Vector Index ◽  
The Mean ◽  
Highly Correlated ◽  
Mean Cycle ◽  
Activation Vector

Introduction: Electrogram morphology recurrence (EMR) analysis is a novel mapping technique which characterizes morphology patterns during atrial fibrillation (AF). Using high resolution electrical mapping, we tested the hypothesis that EMR analysis could identify areas of consistent activation directions and rotor activity in a canine rapid atrial pacing model of AF. Methods: Three weeks of rapid right atrial pacing (600 bpm) was performed in six dogs. A triangular plaque was used to obtain 117 simultaneous bipolar AF electrograms from two right and three left atrial locations. EMR plots for each electrogram recording were created by cross-correlation of each activation waveform with each other. The percentage of the most common morphology (REC%) and the mean cycle length (CL) of activations with the most common morphology (CLR) were computed. Activation pattern for each site was classified as either having stable rotors, passive activity, or chaotic activity. Activation vectors were computed and a vector index (VI) was used to measure vector consistency. Results: Figure A shows an example of an EMR plot map from recordings in the left atrium with red indicating areas of high EMR. The sites with the shortest CL had an average CL of 81±13 ms. The sites with the highest REC% had an average value of 99±2%. The sites with the shortest CLR had an average value of 91±17 ms. REC% was highly correlated with VI (Figure B). Minimum CL was only moderately shorter in rotor sites compared to chaotic and passive sites (Figure C). Maximum REC% was significantly higher in rotors sites than in chaotic sites, but not different from passive sites (Figure D). Minimum CLR in the rotor sites were significantly less than both the chaotic and passive sites (Figure E). Conclusions: EMR analysis is a new mapping technique that correlates well with activation vector consistency and can identify rotor activity. This is a promising method for mapping AF that may identify sources that can be targeted for ablation.

Local Capture by Atrial Pacing in Spontaneous Chronic Atrial Fibrillation

Circulation ◽  
1997 ◽  
Vol 95 (10) ◽  
pp. 2416-2422 ◽  
Author(s):  
Claudio Pandozi ◽  
Leopoldo Bianconi ◽  
Mauro Villani ◽  
Antonio Castro ◽  
Giuliano Altamura ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Chronic Atrial Fibrillation ◽  
Atrial Pacing ◽  
Local Capture

A cool modality to restore sinus rhythm

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
O Yasin ◽  
A Sugrue ◽  
M Van Zyl ◽  
A Ladejobi ◽  
J Tri ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Body Temperature ◽  
Sinus Rhythm ◽  
Animal Experiments ◽  
Funding Source ◽  
Atrial Pacing ◽  
Exact Test ◽  
Chi Squared ◽  
Cool Device ◽  
Atrial Defibrillation

Abstract Background Slowing electrical conduction by cooling the myocardium can be used for defibrillation. We previously demonstrated the efficacy of a small cold device placed in oblique sinus (OS) in terminating atrial fibrillation (AF). However, the parameters needed to achieve effective atrial defibrillation are unknown. Purpose Assess effect of the size of cooled myocardium on frequency of AF termination in acute canine animal models. Methods Sternotomy was performed under general anesthesia in 10 acute canine experiments. AF was induced using rapid atrial pacing and intra-myocardial epinephrine and acetylcholine injections. Once AF sustained for at least 30s, either a cool (7–9°C) or placebo (body temperature) device was placed in the OS. Four device sizes were tested; ½X½, ¾X¾, and 1X1 inch devices and two ¾X¾ inch devices placed side by side simultaneously. Time to AF termination was recorded. Chi-squared or Fisher's exact test were used to compare the frequency of arrhythmia termination with cooling versus placebo. Results A total of 166 applications were performed (89 cool vs 77 placebo) in 10 animal experiments. Overall, AF terminated in 82% of the cooling applications vs. 67.5% of placebo (P=0.03, Figure 1). For the ½X½ inch device 88% of cold applications restored sinus rhythm vs. 63.6% for placebo (P=0.05). The frequency of sinus restoration for cold ¾X¾, 1X1 and two ¾X¾ side by side devices was 86.7%, 83.3% and 70% respectively. Time to sinus restoration when achieved was within three minutes was also not significantly changed. Conclusion Placing a cool device in the oblique sinus can terminate AF and efficacy is not affected by the size of device. Funding Acknowledgement Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): MediCool Technologies

scholarly journals Distribution of atrial electrogram types during atrial fibrillation: Effect of rapid atrial pacing and intercaval junction ablation

1996 ◽  
Vol 27 (7) ◽  
pp. 1713-1721 ◽  
Author(s):  
Huagui Li ◽  
John Hare ◽  
Kashef Mughal ◽  
David Krum ◽  
Michael Biehl ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Atrial Pacing ◽  
Atrial Electrogram

Atrial fibrillation followed by torsade de pointes degenerated into ventricular fibrillation spontaneously terminated and restored sinus rhythm

2013 ◽  
Vol 166 (3) ◽  
pp. e39-e40 ◽  
Author(s):  
Francesco Santoro ◽  
Riccardo Ieva ◽  
Armando Ferraretti ◽  
Luisa De Gennaro ◽  
Matteo Di Biase ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Ventricular Fibrillation ◽  
Sinus Rhythm ◽  
Torsade De Pointes
Sign in / Sign up

Export Citation Format

Share Document