Evaluation Of Mechanical Movement Function Of Paced Myocardium Based On 3D Functional Mapping Model Of Left Ventricular

Cardiovascular diseases have the highest death rate of all dieases in the world. In the past twenty years, with the improvement of medicine and relative science, implanting artificial pacemakers is an effective interventional treating means for the heart beating slowly patient who character with sick sinus syndrome(SSS) and atria ventricle block(AVB). In traditional, the curative effect of pacemakers is evaluated from hemodynamics and cardio-electrophysiology, in this thesis, a standard 3D model of left ventricle (LV)is developed to study the mechanical behavior of sick and paced myocardium, with the expect of evaluting the effect of pacing.In this thesis, the 3D model is built by turning based on 2D LV section plane. This model which ignores the anatomical structure of LV is considered as a reference space for reducing individual differences among different LVs. We pay attention to the local motion of myocardium with bridge of myocardium segments.Following, we match the 2D clinical image with the corresponding position of the 3D model with the principle of medicial image registration,and add the color of 2D image to 3D model. The registrion in this paper consider rigid registrion and non-rigid registrion.The rigid registrion realize orientation and scale match of two images with equivalent inertia ellipse, then non-rigid images complete the distortion of them with polynomial. As the restrict of image scan angle,not all vertex of the model have 2D corresponding images, the color of unknown vertex can receive by interpolation. We use centroid interpolation in this paper. Then, we realize velocity mapping following above.In order to verify feasibility of the methodology, we collection three case of Doppler Tissue Velocity image of the patient who has embeded pacemakers and one case of healthy people. Firstly, compared the velcoity of mapping 3D model of case one before and after operation,we concluded:a) after operation, the movement of the dys-function myocardium has been improved, and the myocardium appear harmonious heart-oritented movement; b)after operation,the peak velocity of mitral valve is quicker than before,and the velocity gradient of endocardium and epicardium has improved.This phenomena show that the systole ability of myocardium has toned up; c)after operation, the transmition of myocardium movement has appeared conformanced. Then, we compare the velocity mapping of 3D model of paced patient and the healthy man in the aspect of the transmission of velocity and velocity of mitral valve and the velocity gradient of endocardium and epicardium, conclude that:the peak velocity of mitral valve and the velocity gradient of endocardium and epicardium after operation are all improved, but the ability of improvement of myocardium of DDD pacer is stronger than the VVI one. Also, the transverse and lognitudinal transmition direction of all three cases are different with healty people, and dys-synchronization of velocity exist.In this thesis, we provide a method for studying the mechanical movement of myocardium based on 3D mapping models and image registration. The result indicate that this method is intuitionistic and dynamic-observational in research of mechanical movement of paced myocardium, and it can be used in evaluation of pacemaker.