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Effect of mechanical synchrony on ventricular contractility

机械同步性对心室收缩力的影响

基本信息

批准号：
62570398
负责人：
SUNAGAWA Kenji
金额：
$ 1.28万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-62570398/
关键词：
synchrony contaractility 心収縮力収縮同期心収縮の同期性摘出潅流心

项目摘要

We investigated how myocardial mechanical synchrony influences ventricular contractility. To dissociate the myocardial time varying property E(t) and synchrony s(t) of cardiac contraction, we hypothesized that the time varying ventricular property e(t) can be approximated by a convolution of s(t) and e(t). To examine the hypothesis, we determined e(t) of isolated crosscirculated canine heart using a time domain direct deconvolution technique. The result indicated that a(t) derived from the early phase of contraction has longer duration of the mechanical contraction than that obtained from the late phase of contraction. Since the electrical depolarizaion propagates from the endocardium to epicardium, this is to say that the duration of the mechanical contraction would be longer in the endocardial myocardium than epicardial myocardium. This was evidenced by the fact that the mass pacing of the heart resulted in lower contractility than atrial pacing.If the convolutional model is sound, we should be able to obtain e(t) even from the heart in ventricular fibrillation. We Fourier analyzed left ventricular pressure of fibrillating heart and deconvolved it using a homomorphic deconvolution technique. The e(t) thus determined matched reasonably well with that obtained by the time domain deconvolution. Therefore the convolutional model of the left ventricle appears to integrally characterize the relationship between myocardial property e(t) and synchrony s(t) of cardiac contraction.

我们研究了心肌机械同步性如何影响心室收缩力。为了分离心肌时变特性E（t）和心脏收缩的同步性s（t），我们假设时变心室特性e（t）可以通过s（t）和e（t）的卷积来近似。为了验证这一假设，我们使用时域直接去卷积技术测定了离体交叉循环犬心脏的e（t）。结果表明，由收缩早期得到的a（t）比由收缩晚期得到的a（t）具有更长的机械收缩持续时间。由于电去极化从心内膜向心外膜传播，也就是说，心内膜心肌的机械收缩持续时间比心外膜心肌长。这一点可以通过心脏的整体起搏导致比心房起搏更低的收缩性来证明。如果卷积模型是合理的，我们甚至可以从心室颤动的心脏中获得e（t）。我们对离体心脏的左心室压力进行傅立叶分析，并采用同态反卷积技术进行反卷积。这样确定的e（t）与通过时域反卷积获得的相当好地匹配。因此，左心室的卷积模型似乎整体地表征了心肌性质e（t）与心脏收缩的同步性s（t）之间的关系。