Spatiotemporal estimation of activation times of fractionated ECGs on complex heart surfaces

Abstract

Identification of electrical activation or depolarization times on sparsely-sampled complex heart surfaces is of importance to clinicians and researchers in cardiac electrophysiology. We introduce a spatiotemporal approach for activation time estimation which combines prior results using spatial and temporal methods with our own progress on gradient estimation on triangulated surfaces. Results of the method applied to simulated and canine heart data suggest that improvements are possible using this novel combined approach.

Delay-Based Regularization for ECG Imaging of Transmembrane Voltages

“…We first apply a temporal Gaussian filter (order 2, σ = 12 ms) to TMVs. As signal for cross-correlation, we then use the product of the surface gradient norm and the temporal derivative, as originally suggested for deflection-based AT estimation in [8]. Delays for new reconstructions are then calculated as differences of corresponding ATs.…”

Forcing Transmembrane Voltages to Decrease Slowly: A Temporal Regularization for ECG Imaging

“…Local activation times (LAT) are extracted and compared as described in [2]. In short, the peaks of a spatio-temporal derivative signal [8] are detected and absolute errors between only true positive detections are calculated together with the false negative rate (FNR) and the false positive rate (FPR).…”

ECG Imaging of Simulated Atrial Fibrillation: Imposing Epi-Endocardial Similarity Facilitates the Reconstruction of Transmembrane Voltages

“…Local activation times (LAT) for each node are extracted by detecting the peaks of the following signal [6]:…”