An automated algorithm for determining conduction velocity, wavefront direction and origin of focal cardiac arrhythmias using a multipolar catheter

Abstract

Determining locations of focal arrhythmia sources and quantifying myocardial conduction velocity (CV) are two major challenges in clinical catheter ablation cases. CV, wave-front direction and focal source location can be estimated from multipolar catheter data, but currently available methods are time-consuming, limited to specific electrode configurations, and can be inaccurate. We developed automated algorithms to rapidly identify CV from multipolar catheter data with any arrangement of electrodes, whilst providing estimates of wavefront direction and focal source position, which can guide the catheter towards a focal arrhythmic source. We validated our methods using simulations on realistic human left atrial geometry. We subsequently applied them to clinically-acquired intracardiac electrogram data, where CV and wavefront direction were accurately determined in all cases, whilst focal source locations were correctly identified in 2/3 cases. Our novel automated algorithms can potentially be used to guide ablation of focal arrhythmias in real-time in cardiac catheter laboratories.

Spatial Resolution Requirements for Accurate Identification of Drivers of Atrial Fibrillation

“…If the catheter does not lie over the rotor core, techniques presented by Roney et al 31 could be used to direct the catheter toward the rotor, but these techniques are dependent on some degree of organization of wavefronts remote from the driver. In addition, it may be necessary to consider the activity of surrounding electrograms to differentiate rotors from interactions around lines of block.…”

Post-operative atrial fibrillation is associated with a pre-existing structural and electrical substrate in human right atrial myocardium

“…Activation time was defined as the time from first to last activation of the AFocus. Conduction velocity (CV) was calculated from the manually annotated activation times using Matlab [25]. This enabled visualisation of propagation across the AFocus II as an isochronal map and estimated CV both using planar and circular conditions.…”

The contact electrogram and its architectural determinants in atrial fibrillation

“…Wavefront propagation results are divided into paced rhythms, where a single wavefront would be expected to propagate (results section 8) and during AF (results section 9). The recording and calculation of such data in human AF is a promising area of clinical research which this work directly contributes to Roney, Cantwell, Qureshi, et al, 2014). CV heterogeneity, quantified by variance, is an important arrhythmic factor and one of the initial conditions stated by Mines for re-entry (Mines, 1913).…”

“…This was calculated from the manually annotated activation times by a custom Matlab script (Roney, Cantwell, Qureshi, et al, 2014). This helped visualised propagation across the AFocus II as an isochronal map and estimate CV based on either the wavefront being a planar wavefront or a circular shape.…”

“…Recent studies measuring CV in humans in vivo show typical conduction slowing precedes AF but employed conduction time (Lalani, Schricker, Gibson, et al, 2012;Schricker, Lalani, Krummen, et al, 2014) or used assumptions about wavefront shape which may break down in conditions such as AF (Weber, Luik, Schilling, et al, 2011). The CV methods detailed in this thesis were developed with the help of Dr Caroline Roney (Roney, Cantwell, Qureshi, et al, 2014) and…”