Session S94.4

Data Fusion of Left Ventricle Electro-Anatomic Mapping and Multislice Computerized Tomography for Cardiac Resynchronisation Therapy Optimization

F Tavard, A Simon*, C Leclercq, P Mabo,
A Hernandez, M Garreau

Université de Rennes
Rennes, France

Bi-ventricular Cardiac Resynchronization Therapy (CRT) is a treatment for inter or intra ventricular asynchronism, that requires three pacing leads, one of them implanted on the left cardiac wall through the coronary veins. This CRT technique can be optimized by the identification of the most effective pacing sites through the use of combined anatomical, mechanical or electrical information provided by cardiac imaging modalities. The aim of this study is to provide a helpful tool to perform this identification by the fusion of electrical and anatomical information respectively issued from Electro-Anatomical Mapping (EAM) data and Multislice Computerized Tomography (MSCT) imaging. In order to represent this information in a unified framework, a three steps method is proposed: (1) EAM data provide an approximation of the LV 3D-surface (S_EAM). On the other hand, the LV is segmented from the MSCT imaging. First, the left cardiac chambers are segmented using a fuzzy connectedness algorithm [Fleureau, CinC 2008]. Then, the LV is separated from the left auricle by cutting the 3D segmented surface at the mitral valvular plane level. This plane results in a narrowing of the ventricular structure area among the great axis. Therefore this area is used as the criterion of an optimization process defining the valvular mitral plane and providing S_MSCT. (2) a semi-automatic rigid registration method is applied to the two LV-surfaces (S_EAM and S_MSCT). This method consists in an automatic registration of the great axis and of the apex, and in a manually chosen rotation of S_EAM around the great axis. (3) the activation time delays are estimated: considering each 3D anatomical point on S_MSCT, its activation time delay is considered as a weighted mean on the activation time delays of its neighbours in the EAM data. This method results in a graphical user interface displaying the time activation delays on S_MSCT. It allows the comparison of different stimulation modes (none, left ventricle,...) through the visualization of corresponding maps. About CRT optimization, this tool provides clinicians with means to identify abnormal electrical activity sites and, displaying the corresponding MSCT images, to select veins that could lead to adapted stimulation sites.

(Abstract Control Number: 219)