心外膜电位仿真研究

SIMULATION STUDY OF EPICARDIAL POTENTIALS

以往的心电理论研究，一方面强调从体表电位分布到心外膜电位分布的求逆；另一方面利用计算机心脏仿真模型只侧重于体表电位的仿真，而忽视了对心外膜电位的仿真，不利于心电逆问题研究的发展。本文阐明了心外膜电位对临床诊断和心电逆问题研究的重要性，并在ＬＦＸ计算机心脏仿真模型［１～３］的基础上建立了心外膜电位仿真的数学描述和心外膜模型。文中对正常心脏和左束支传导阻滞的心外膜电位进行了仿真研究。

Previous electrocardiac theory studies were those either focused on reconstructing epicardial potentials from the body surface potential data, or laid emphasis on simulating the body surface potentials using computer heart models. Epicardial potentials, however, have been neglected. This paper elucidates that the epicardial potentials are important for both clinical diagnosis and ECG inverse problem studies, and presents a procedure of simulating epicardial potentials using a computer heart model with real geometry. To simulate the epicardial potentials, an epicardial surface model was constructed based on the LFX heart-torso model developed earlier. The heart model, together with the epicardial surface model, are mounted in a piecewise homogeneous human torso model. Electric dipoles proportional to the spatial gradient of the action potential, are generated in all cell units. These dipoles give rise to a potential distribution on the epicardial surface, which is calculated by means of the boundary element method. Epicardial potentials of the normal heart and those with left bundle branch block (LBBB) were simulated. The simulation results are in good accordance with clinical measurements reported by Wyndham et al.