Prospective cross‐sectional study using Poisson renewal theory to study phase singularity formation and destruction rates in atrial fibrillation (RENEWAL‐AF): Study design

Abstract

Background Unstable functional reentrant circuits known as rotors have been consistently observed in atrial fibrillation and are mechanistically believed critical to the maintenance of the arrhythmia. Recently, using a Poisson renewal theory‐based quantitative framework, we have demonstrated that rotor formation (λf) and destruction rates (λd) can be measured using in vivo electrophysiologic data. However, the association of λf and λd with clinical, electrical, and structural markers of atrial fibrillation phenotype is unknown. Methods RENEWAL‐AF is a multicenter prospective cross‐sectional study recruiting adult patients with paroxysmal or persistent atrial fibrillation undergoing clinically indicated catheter ablation. Patients will undergo intraprocedural electrophysiologic atrial fibrillation mapping, with λf and λd to be determined from 2‐minute unipolar electrogram recordings acquired before ablation. The primary objective will be to determine the association of λf and λd as markers of fibrillatory dynamics with clinical, electrical, and structural markers of atrial fibrillation clinical phenotype, measured by preablation transthoracic echocardiogram and cardiac magnetic resonance imaging. An exploratory objective is the noninvasive assessment of λf and λd using surface ECG characteristics via a machine learning approach. Results Not applicable. Conclusion This pilot study will provide insight into the correlation between λf/λd with clinical, electrophysiological, and structural markers of atrial fibrillation phenotype and provide a foundation for the development of noninvasive assessment of λf/λd using surface ECG characteristics will help expand the use of λf/λd in clinical practice.

M/M/Infinity Birth-Death Processes – A Quantitative Representational Framework to Summarize and Explain Phase Singularity and Wavelet Dynamics in Atrial Fibrillation

“…Future studies are required to address the relationship between M/M/∞ equations and different clinical substrates of AF. Features that could be examined include the relationship between these equations and variant ablation strategies, pulmonary vein behavior, voltage characterization in the atrium, as well as spatial characterization of the rate constants throughout the human atrium ( Quah et al, 2020 ). This will be important to determine the practical utility of the governing equations provided by the M/M/∞ birth–death process.…”

Reconceptualising Atrial Fibrillation Using Renewal Theory: A Novel Approach to the Assessment of Atrial Fibrillation Dynamics

“…[ 18 ] We are prospectively studying these issues in the RENEWAL AF study, which will prospectively recruit patients with different clinical classifications of AF, allowing for a comparison of renewal rate constants to clinical AF features. [ 17 , 71 ]…”

Spatial concentration and distribution of phase singularities in human atrial fibrillation: Insights for the AF mechanism

“…The fact that both tissue and physiological factors are likely to be important to sustaining AF may become clinically relevant in understanding the progression of AF from paroxysmal to persistent as well as determining the likelihood of clinical response to AF ablation. We are currently conducting a prospective clinical study, RENEWAL AF, to explore these questions 46 …”

“…As such, we were not able to specifically measure PS concentrations in the basket catheter and could not draw conclusions regarding the concentration of PSs in the pulmonary veins. Improvements in mapping catheter design and technology may in future be able to address this gap 46 …”