Spatio-temporal registration of electro-anatomical mappings with functional data for CRT optimization

This work is based on the registration and fusion of multimodality data for cardiac resynchronization therapy (CRT) optimization. The goal is to provide local descriptors of the electro-mechanical (EM) coupling of the heart, using anatomical, electrical and mechanical data acquired from CT-scan volumes (CT), speckle tracking echocardiography (STE) and electro-anatomical mapping (EAM). In previous works, we have presented registration methods to place EAM, CT and STE in the same geometrical reference system. In order to extract EM descriptors, data resulting from EAM and STE should be synchronized. This is done according to the ECGs acquired during both acquisitions. However, the number of ECG derivations as well as the cardiac frequencies differ in both acquisitions. In this work, the selection of the most appropriate ECG derivation acquired with EAM is based on the computation of the cross-correlation between the three ECGs from EAM and the one from the STE acquisition. A non-linear mapping (using dynamic time warping) is estimated between the two signals to handle the differences in cardiac frequencies. This whole process enables to represent useful descriptors for CRT resulting from EAM, STE and CT data in the same spatio-temporal reference system. Results are presented on three patients undergoing CRT.