Chen Xiaoxiao, Mukkamala Ramakrishna, Sala-Mercado Javier A, Hammond Robert L, Ichinose Masashi, Soltani Soroor, O'Leary Donal S
Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:5328-31. doi: 10.1109/IEMBS.2009.5332687.
We identified the transfer functions relating beat-to-beat fluctuations in arterial blood pressure to maximal ventricular elastance (ABP-->E(max)) and beat-to-beat fluctuations in heart rate to E(max) (HR-->E(max)) to characterize the dynamic properties of the arterial ventricular contractility baroreflex and force-frequency relation, respectively, in three conscious dogs before and after pacing-induced heart failure. During the control condition, the average gain value, dominant time constant, and time delay were respectively -0.0374 ml(-1), 12.8 sec, and 2 sec for the ABP-->E(max) transfer function and 0.0137 mmHg/ml-bpm, 1.77 sec, and 0 sec for the HR-->E(max) transfer function. During the heart failure condition, both transfer functions were markedly depressed. These results are consistent with known physiology and previous studies and provide perhaps the first quantitative information on the dynamic control of E(max) during normal closed-loop operation.
我们确定了动脉血压逐搏波动与最大心室弹性（ABP→E(max)）以及心率逐搏波动与E(max)（HR→E(max)）之间的传递函数，分别用于表征起搏诱导的心力衰竭前后三只清醒犬的动脉心室收缩性压力反射和力-频率关系的动态特性。在对照状态下，ABP→E(max)传递函数的平均增益值、主导时间常数和时间延迟分别为-0.0374 ml(-1)、12.8秒和2秒，HR→E(max)传递函数的分别为0.0137 mmHg/ml-bpm、1.77秒和0秒。在心力衰竭状态下，两个传递函数均明显降低。这些结果与已知生理学和先前的研究一致，并可能提供了关于正常闭环操作期间E(max)动态控制的首个定量信息。
