A SIMULATION STUDY OF THE EFFECTS OF TORSO INHOMOGENEITIES ON ELECTROCARDIOGRAPHIC POTENTIALS, USING REALISTIC HEART AND TORSO MODELS
A SIMULATION STUDY OF THE EFFECTS OF TORSO INHOMOGENEITIES ON ELECTROCARDIOGRAPHIC POTENTIALS, USING REALISTIC HEART AND TORSO MODELS
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DOI：
10.1161/01.res.52.1.45
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发表时间：
1983-01-01
影响因子：
20.1
通讯作者：
MAILLOUX, GE
中科院分区：
文献类型：
--
作者：
GULRAJANI, RM;MAILLOUX, GE
将23偶极子心脏模型放置在逼真的人体躯干模型中，通过计算机模拟研究了躯干不均匀对心电电位的影响。计算了以下躯干状态下的传递系数：同质、同质+骨骼肌层、同质+肌层+肺+脑室内血块，以及体表电位图、心电向量图和12导联心电图。通过比较纳入前后的结果，得出各非均质性的影响。对于单个偶极传递系数，证实了Brody效应的有效性，即高电导率血块增加了径向取向的偶极子，而减小了切向取向的偶极子。关于心电向量图、心电图和体表电位图，主要的定性影响是由于肺部的原因，心电向量图的头到脚分量增大，心电切迹(时间滤波)和体表电位图的等电位等值线(空间滤波)变得平滑，从而造成信息损失，这是由于血块、肌肉层和肺部造成的，程度较小。除了上述不均匀性的定性影响外，对表面电位也有很大的定量影响，即由于血块导致的幅度增加，以及由于肌层的幅度降低，如果不能解释，可能会危及心脏偶极子来源的这些电位的逆解。
The effects of torso inhomogeneites on ECG potentials were investigated via computer simulation, using a 23-dipole heart model placed within a realistically shaped human torso model. The transfer coefficients relating the individual dipoles to the torso surface potentials, as well as the body surface potential maps, the vectorcardiogram and the 12-lead ECG resulting due to normal activation of the heart model, were calculated for each of the following torso conditions: homogeneous, homogenous + skeletal muscle layer, homogeneous + muscle layer + lungs, and homogeneous + muscle layer + lungs + intraventricular blood masses. The effects of each inhomogeneity were deduced by comparing results before and after its inclusion. For individual dipole transter coefficients the validity of the Brody effect was confirmed, whereby the high conductivity blood masses augmented radially oriented dipoles and diminished tangentially oriented ones. With regard to the vectorcardiogram, the ECG and the body surface potential maps, the major qualitative effects were an augmentation of the head-to-foot component of the vectorcardiogram due to the lungs, and a smoothening of notches in the ECG (temporal filtering) and of isopotential contours in the body surface potential maps (spatial filtering) with a consequent loss of information, due to the blood masses, muscle layer and, to a lesser extent, the lungs. Besides the above qualitative effects of the inhomogeneities, there were also large quantitative effects on the surface potentials, i.e., magnitude increases due to the blood masses and magnitude decreases due to the muscle layer that, if unaccounted for, could compromise the inverse solution of these potentials for the cardiac dipole sources.