Cycle Length Evaluation in Persistent Atrial Fibrillation Using Kernel Density Estimation to Identify Transient and Stable Rapid Atrial Activity

Abstract

Purpose Left atrial (LA) rapid AF activity has been shown to co-localise with areas of successful atrial fibrillation termination by catheter ablation. We describe a technique that identifies rapid and regular activity. Methods Eight-second AF electrograms were recorded from LA regions during ablation for psAF. Local activation was annotated manually on bipolar signals and where these were of poor quality, we inspected unipolar signals. Dominant cycle length (DCL) was calculated from annotation pairs representing a single activation interval, using a probability density function (PDF) with kernel density estimation. Cumulative annotation duration compared to total segment length defined electrogram quality. DCL results were compared to dominant frequency (DF) and averaging. Results In total 507 8 s AF segments were analysed from 7 patients. Spearman’s correlation coefficient was 0.758 between independent annotators (P < 0.001), 0.837–0.94 between 8 s and ≥ 4 s segments (P < 0.001), 0.541 between DCL and DF (P < 0.001), and 0.79 between DCL and averaging (P < 0.001). Poorer segment organization gave greater errors between DCL and DF. Conclusion DCL identifies rapid atrial activity that may represent psAF drivers. This study uses DCL as a tool to evaluate the dynamic, patient specific properties of psAF by identifying rapid and regular activity. If automated, this technique could rapidly identify areas for ablation in psAF.

Evaluation of RETRO‐Mapping for electrophysiological features including direction of plane activity during atrial fibrillation using multipolar catheters in humans

“…Our histogram distribution suggests that our CV and CL algorithms return reasonable values compared to the literature 15,16 . This indicates that RETRO‐Mapping can potentially measure key features such as CL and CV during AF.…”

“…Our histogram distribution suggests that our CV and CL algorithms return reasonable values compared to the literature. 15,16 This indicates that RETRO-Mapping can potentially measure key features such as CL and CV during AF. This should be formally validated in a study comparing the behaviors of different types of wavefronts such as focal, collision, and rotational activities.…”

Catheter Ablation With Morphologic Repetitiveness Mapping for Persistent Atrial Fibrillation

“…2 A new driverguided method has emerged as an alternative approach, and other various mapping methods have yielded some encouraging results in small populations. [3][4][5][6][7] Previous prospective studies by Lin et al 8 and Narayan et al 9 evaluated the substrate modification guided by repetitive and/or organized similar electrography to eliminate rotors and focal sources. From these studies, electrogram similarity analysis could be used to detect regions with stable activation waveforms in the atria regardless of the spatial wavefront propagations.…”

“…The optimal ablation strategy for persistent AF remains undetermined, and an alternative approach should be explored . A new driver-guided method has emerged as an alternative approach, and other various mapping methods have yielded some encouraging results in small populations …”

An Efficient Hybrid Methodology for Local Activation Waves Detection under Complex Fractionated Atrial Electrograms of Atrial Fibrillation

“…CFAEs are defined as electrograms (EGMs) with activations of ≥2 deflections and/or perturbed baseline or as EGMs with a cycle length (CL) ≤ 120 ms [ 18 ]. While CFAEs’ detection can be performed without CL estimation, many techniques suggest the CL-based CFAEs definition in order to locate candidate CA targets [ 19 , 20 , 21 ]. As CL is defined by the distance in samples between two consecutive local activation waves (LAWs) [ 22 ], this requires the prior detection of LAWs.…”