Modified maximum time difference intracardiac conduction velocity estimation

The cardiac conduction velocity vector (VV) at a desired point in any chamber of the heart can be estimated by processing the local intracardiac electrograms, i.e., the activation times (ATs) and the locations of the recording catheter's electrodes can be used for the VV estimation. In this paper, we modify the maximum time difference (MTD) method, which is a simple computational efficient cardiac VV estimation approach. In the MTD, first, the ATs of the electrograms are extracted, and the corresponding wavefronts are estimated. For each wavefront, the VV is estimated as the vector connecting the first to the last activated electrodes of the catheter divided by the time duration between the activation of those two electrodes. In the proposed modified MTD (MMTD) approach, which is slightly more computationally complex than the MTD, we divide the ATs of each considered wavefront into two groups, such that one group contains the electrodes with early activations, and the other contains those with late activations. We properly assign a time value and a location value to these groups and follow the same procedure as the MTD method to estimate the VV using the assigned values. Using synthetic data, we show that the proposed MMTD improves the quality of the cardiac conduction VV estimation of the MTD method, i.e., the MMTD is more robust to the AT estimation error and is able to determine the VV of the planar wavefronts more accurately.