Objective: Atrial dominant frequency (DF) maps undergoing atrial fibrillation (AF) presented good spatial correlation with those obtained with the non-invasive body surface potential mapping (BSPM). In this study, a robust BSPM-DF calculation method based on wavelet analysis is proposed.Approach: Continuous wavelet transform along 40 scales in the pseudo-frequency range of 3-30 Hz is performed in each BSPM signal using a Gaussian mother wavelet. DFs are estimated from the intervals between the peaks, representing the activation times, in the maximum energy scale. The results are compared with the traditionally widely applied Welch periodogram and the robustness was tested on different protocols: increasing levels of white Gaussian noise, artificial DF harmonics presence and reduction of number of leads. 11 AF simulations and 12 AF patients are considered in the analysis. For each patient, intracardiac electrograms were acquired in 15 locations from both atria. The accuracy of both methods was assessed by calculating the absolute errors of the HDF B SP M with respect to the atrial HDF, either simulated or intracardially measured, and assumed correct if ≤ 1 Hz. The spatial distribution of the errors between torso DFs and atrial HDFs were compared with atria driving mechanisms location. Torso HDF regions, defined as portions of the maps with |DF −HDF B SP M | ≤ 0.5 Hz were identified and the percentage of the torso occupied these regions was compared between methods.
Main results:The proposed method allowed a significant improvement on non-invasive estimation of the atria HDF (median relative error of 7.14% vs. 60.00%, p = 0.06), outperforming the Welch approach in correct estimations of atrial HDFs non-invasively for both cases: models (81.82% vs 45.45%) and patients (75.00% vs 66.67%). A low positive BSPM-DF maps correlation was seen between techniques (0.47 for models and 0.63 for patients), highlighting overall differences in DF distributions. The method was more robust to white Gaussian noise and harmonics and presented more consistent results in lead layouts with low spatial resolution (p = 0.99 vs. p = 0.94).Significance: Estimation of atrial HDFs using BSPM is improved by the proposed waveletbased algorithm, helping increase the non-invasive diagnostic ability in AF.