title: A study of mechanical optimization strategy for cardiac resynchronization therapy based on an electromechanical model.
abstract: An optimal electrode position and interventricular (VV) delay in cardiac resynchronization therapy (CRT) improves its success. However, the precise quantification of cardiac dyssynchrony and magnitude of resynchronization achieved by biventricular (BiV) pacing therapy with mechanical optimization strategies based on computational models remain scant. The maximum circumferential uniformity ratio estimate (CURE) was used here as mechanical optimization index, which was automatically computed for 6 different electrode positions based on a three-dimensional electromechanical canine model of heart failure (HF) caused by complete left bundle branch block (CLBBB). VV delay timing was adjusted accordingly. The heart excitation propagation was simulated with a monodomain model. The quantification of mechanical intra- and interventricular asynchrony was then investigated with eight-node isoparametric element method. The results showed that (i) the optimal pacing location from maximal CURE of 0.8516 was found at the left ventricle (LV) lateral wall near the equator site with a VV delay of 60 ms, in accordance with current clinical studies, (ii) compared with electrical optimization strategy of E(RMS), the LV synchronous contraction and the hemodynamics improved more with mechanical optimization strategy. Therefore, measures of mechanical dyssynchrony improve the sensitivity and specificity of predicting responders more. The model was subject to validation in future clinical studies.
authors.affiliation: Department of Anesthesiology, General Hospital of Guangzhou Military Command, Guangzhou, China.
authors.forename: Jianhong
authors.initials: J
authors.lastname: Dou
authors.forename: Ling
authors.initials: L
authors.lastname: Xia
authors.forename: Dongdong
authors.initials: D
authors.lastname: Deng
authors.forename: Yunliang
authors.initials: Y
authors.lastname: Zang
authors.forename: Guofa
authors.initials: G
authors.lastname: Shou
authors.forename: Cesar
authors.initials: C
authors.lastname: Bustos
authors.forename: Weifeng
authors.initials: W
authors.lastname: Tu
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Stuart
authors.initials: S
authors.lastname: Crozier
mesh_terms: D000465:Algorithms; D000818:Animals; D001331:Automation; D002304:Cardiac Pacing, Artificial / Q000379:methods; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D019295:Computational Biology / Q000379:methods; D003952:Diagnostic Imaging / Q000379:methods; D004285:Dogs; D004566:Electrodes; D004594:Electrophysiology / Q000379:methods*; D006321:Heart / Q000502:physiology; D006333:Heart Failure / Q000628:therapy*; D006352:Heart Ventricles / Q000503:physiopathology; D021621:Imaging, Three-Dimensional / Q000379:methods; D015233:Models, Statistical; D008962:Models, Theoretical; D018487:Ventricular Dysfunction, Left / Q000628:therapy