Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Sep;32(9):2393-2403.
doi: 10.1111/jce.15170. Epub 2021 Jul 28.

Spatial and temporal variability of rotational, focal, and irregular activity: Practical implications for mapping of atrial fibrillation

Michael Tb Pope  1   2 , Pawel Kuklik  3 , Andre Briosa E Gala  1   2 , Milena Leo  1 , Michael Mahmoudi  2 , John Paisey  2 , Timothy R Betts  1   4
Affiliations

Spatial and temporal variability of rotational, focal, and irregular activity: Practical implications for mapping of atrial fibrillation

Michael Tb Pope et al. J Cardiovasc Electrophysiol. 2021 Sep.

Abstract

Background: Charge density mapping of atrial fibrillation (AF) reveals dynamic localized rotational activation (LRA), irregular activation (LIA) and focal firing (FF). Their spatial stability, conduction characteristics and the optimal duration of mapping required to reveal these phenomena and has not been explored.

Methods: Bi-atrial mapping of AF propagation was undertaken using AcQMap (Acutus Medical) and variability of activation patterns quantified up to a duration of 30 s. The frequency of each pattern was quantified at each unique point of the chamber over two separate 30-s recordings before ablation and R2 calculated to quantify spatial stability. Regions with the highest frequency were identified at increasing time durations and compared to the result over 30 s using Cohen's kappa. Properties of regions with the most stable patterns were assessed during sinus rhythm and extrastimulus pacing.

Results: In 21 patients, 62 paired LA and RA maps were obtained. LIA was highly spatially stable with R2 between maps of 0.83 (0.71-0.88) compared to 0.39 (0.24-0.57), and 0.64 (0.54-0.73) for LRA and FF, respectively. LIA was most temporally stable with a kappa of >0.8 reached by 12 s. LRA showed greatest variability with kappa >0.8 only after 22 s. Regions of LIA were of normal voltage amplitude (1.09 mv) but showed increased conduction heterogeneity during extrastimulus pacing (p = .0480).

Conclusion: Irregular activation patterns characterized by changing wavefront direction are temporally and spatially stable in contrast with LRA that is transient with least spatial stability. Focal activation appears of intermediate stability. Regions of LIA show increased heterogeneity following extrastimulus pacing and may represent fixed anatomical substrate.

Keywords: AcQMap; atrial fibrillation; charge density mapping; localized irregular activation; spatiotemporal stability.

PubMed Disclaimer

Conflict of interest statement

Michael TB Pope has received honoraria and support for conference attendance from Acutus Medical. Pawel Kuklik provides consultancy services to Acutus Medical. Timothy R Betts has received honoraria from Acutus Medical and is a member of their Medical Advisory Board. The other authors declare that there are no conflict of interests.

Figures

Figure 1
Figure 1
Dynamic AcQTrack analysis identifies each activation pattern including focal firing (FF) (A) characterized by radial activation from a central earliest point, localized rotational activation (LRA) (B) where smooth rotational activation of >270° is observed; and localized irregular activation (LIA) (C). LIA includes a range of specific patterns of activation, all characterized by changing wavefront direction of >90° (C–F, dynamic AcQTrack detection not shown). Color scale depicts the leading (red) to trailing edge (purple) of a wavefront with the full color spectrum occupying 80 ms. LAA, left atrial appendage; LUPV, left upper pulmonary vein; MV, mitral valve
Figure 2
Figure 2
Fluoroscopic image of catheters positioned for simultaneous bi‐atrial noncontact mapping
Figure 3
Figure 3
Method for AcQTrack pattern quantification. A static map is generated (A) quantifying all pattern occurrences at every vertex of the chamber anatomy. Each occurrence is identified in space and time as a single disc allowing calculation of the total number of occurrences, the percentage time they are present, and the proportion of the chamber surface area affected. See also Figure S3
Figure 4
Figure 4
Threshold method. Cut off values for LIA are generated according to the total time the pattern is detected using thresholds gradually excluding more infrequent occurrences (see text for detailed explanation). LAA, left atrial appendage; MV, mitral valve; RUPV, right upper pulmonary vein
Figure 5
Figure 5
Antero‐posterior (top row) and postero‐anterior (lower row) views the left atrium showing the density and distribution of localized irregular activation, localized rotational activation and focal firing (red = no occurrences, purple = highest density) in Patient 10. Each pair of images represent 2 sequential 30‐s maps. Graphs below represent correlation plots for each anatomy vertex (1st map X axis, 2nd Y axis) with R 2 for LIA 0.92, LRA 0.39, and FF 0.49. Inset graph shows correlation for regions with FF frequency ≥1 every 3 s on the first map with R 2 of 0.74. FF, focal firing; LIA, localized irregular activation; LRA, localized rotational activation
Figure 6
Figure 6
Boxplots (A–C) showing the distribution of kappa values in 5‐s increments for regions with high frequency (at the 30% cut off) LIA, LRA, and FF respectively compared to the result after 30 s. Kappa values for the LIA, LRA, and FF are shown at 1‐s increments in (D) showing the point at which the kappa value (representing a very good level of agreement) reaches 0.8. FF, focal firing; LIA, localized irregular activation; LRA, localized rotational activation
See this image and copyright information in PMC

Comment in

References

    1. Narayan SM, Krummen DE, Shivkumar K, Clopton P, Rappel WJ, Miller JM. Treatment of atrial fibrillation by the ablation of localized sources: CONFIRM (Conventional Ablation for Atrial Fibrillation With or Without Focal Impulse and Rotor Modulation) trial. J Am Coll Cardiol. 2012;60(7):628‐636. - PMC - PubMed
    1. Haissaguerre M, Hocini M, Denis A, et al. Driver domains in persistent atrial fibrillation. Circulation. 2014;130(7):530‐538. - PubMed
    1. Child N, Clayton RH, Roney CH, et al. Unraveling the underlying arrhythmia mechanism in persistent atrial fibrillation: results from the STARLIGHT study. Circ Arrhythm Electrophysiol. 2018;11(6):e005897. - PubMed
    1. Honarbakhsh S, Schilling RJ, Dhillon G, et al. A novel mapping system for panoramic mapping of the left atrium: application to detect and characterize localized sources maintaining atrial fibrillation. JACC Clin Electrophysiol. 2018;4(1):124‐134. - PMC - PubMed
    1. Honarbakhsh S, Hunter RJ, Ullah W, Keating E, Finlay M, Schilling RJ. Ablation in persistent atrial fibrillation using stochastic trajectory analysis of ranked signals (STAR) mapping method. JACC Clin Electrophysiol. 2019;5(7):817‐829. - PubMed

Publication types