Preliminary computational framework to map MRI-derived markers to predict response to cardiac resynchronization therapy

Prediction of the response to cardiac resynchronization therapy (CRT) is still uncertain. On our previous CRT clinical research, we have found that a decrease in the ratio between the two principal axes of the 3D trajectory of the electrode at the pacing site (S1/S2) recorded before and after pacing could define a marker between responders and non-responders to CRT. The aim of this work is to design a framework to map the S1/S2 marker on the 3D ventricular anatomy as a preliminary test to verify if the concept of the S1/S2 may predict the response to CRT in a pre-implant scenario. Based on MR images of a CRT candidate, the 3D mesh of the left ventricle geometry is constructed. Using image registration we are able to track the deformation of the mesh throughout the cardiac cycle and to compute the trajectory of each point of the mesh. Then the S/S2 is calculated for every trajectory and mapped on a 3D geometry representation. We have applied this framework to one CRT patient, highlighting that in the area in which the electrode was placed the S/S2 was low. This value suggests a poor possibility of a pacing-induced decrease for the S1/S2 ratio after implant. Consistently the patient was classified as non-responder at the clinical follow-up. Ongoing work focuses on the clinical validation of S1/S2 as a tool for the prediction of CRT response and the acquisition of MR data of potential candidates to CRT for the assessment of the presented framework.