心脏电活动的数学物理问题和高频心电图计算机模拟

MATHEMATICAL AND PHYSICAL PROBLEMS INVENTRICULAR ELECTRO-ACTIVITY ANDCOMPUTER EMULATION OF HFECG

本文利用正常心脏和病变心脏电活动模型以及躯于模型建立了产生常规心电图和高频心电图的数学物理问题，找出了用计算机解决这类数学物理问题的途径，并且用计算机模拟出正常心脏和异常（有病灶）心脏，包括病灶位置变化、病灶大小不同以及病灶不同严重程度等情况下，心电波图形的变化，显示出ＱＲＳ彼上高频切迹和扭结对病灶特性的敏感性和特异性，研究高频心电图ＱＲＳ波上的切迹、扭结的大小和分布状态与心脏疾病的内在联系。

Recent studies have analyzed the high frequency electrocardiogra-phy ( HFECG ) ,and efforts have been made to increase the diagnosticsensitivity of the electrocardiogram by observing its high frequency-components.It was found that the high frcquency notches and slurs onQRS complex are of high sensitivity to physiological condition of myo-cardium. In this paper, a homogeneous torso model with 20-dipole rep-resenting heart electro-activity is introduced. Using finite-elementmethod, body surface potential is calculated, and 85ms QRS complexof 12-lead HFECG is obtained accordingly. In this model, a close rel-ationship between 20-dipole and physiological condition of myocardiumis also built and relationship between physiological condition of myoc-ardium and high frequency notches and slurs on QRS complex is stud-ied. Changing physiological condition of a certain region of ventricleit is found that when the region is small, such as 0.5-lmm, there areno notches or slurs on QRS complex. When the rcgion is a little larger,such as 2-6mm, notches and slurs appear. If still enlarging the region,notches and slurs disappear. It is also found that when the region isnear the endocardium, notches and slurs appear on the upstroke ofQRS complex,and when the region is near epicardium,notches and slursappear on the downstroke of QRS complex. When the region is ondifferent part of ventricle, notches and slurs appear on different leads.Still it is found that when the more the physiological condition changes,the more the will be the action potential waveform changes and thenu-mber of notches and slurs increase. Sometimessome slurs may changeinto notches.