Koiwa Y, Ohyama T, Takagi T, Kikuchi J, Honda H, Hashiguchi R, Shimizu Y, Butler J P, Takishima T
First Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan.
Front Med Biol Eng. 1988;1(1):59-70.
Several investigators have aimed to clarify the patient's left ventricular (LV) physical properties by free vibration analysis of heart sound. Recently we have developed a transfer function (TF) method to calculate the LV viscoelasticity. To clarify whether this TF method and a clinical first heart sound (1 HS) analysis are based on the identical ventricular vibration mode analysis, we examined (1) the visualized LV vibration image in the TF method and (2) the quantitative relationship between the peak frequency of the 1 HS spectrum and that of TF curve in the early and late phase of the 1 HS. Isolated isovolumic potassium arrested canine left ventricles were used to visualize the vibration mode in describing the TF (N = 2). Examination of stroboscopically illuminated, slow-motion images revealed the oscillation of the ventricle to be of mode 2 behavior. To analyze the quantitative relation between the TF method and 1 HS analysis we used ten open-chest dogs. The correlation was good (r = 0.917) when the peak frequency of the TF curve at the early phase of the 1 HS was compared to the peak frequency of the 1 HS. We concluded that both the TF method and 1 HS analysis were based on the common, second-order ventricular vibration mode. Therefore, some information on the ventricular physical properties suggeted by the TF method could also be included in the clinical data obtained by 1 HS analysis.
几位研究人员旨在通过心音的自由振动分析来阐明患者左心室（LV）的物理特性。最近我们开发了一种传递函数（TF）方法来计算左心室的粘弹性。为了阐明这种TF方法和临床第一心音（1HS）分析是否基于相同的心室振动模式分析，我们研究了（1）TF方法中可视化的左心室振动图像，以及（2）第一心音早期和晚期1HS频谱的峰值频率与TF曲线峰值频率之间的定量关系。使用离体等容钾停搏犬的左心室来可视化描述TF时的振动模式（N = 2）。对频闪照明的慢动作图像的检查显示心室振荡为模式2行为。为了分析TF方法与1HS分析之间的定量关系，我们使用了十只开胸犬。当将第一心音早期TF曲线的峰值频率与第一心音的峰值频率进行比较时，相关性良好（r = 0.917）。我们得出结论，TF方法和1HS分析均基于共同的二阶心室振动模式。因此，TF方法所提示的一些关于心室物理特性的信息也可能包含在通过1HS分析获得的临床数据中。
