Heart valve closure timing intervals in response to left ventricular blood pressure

作     者：Hong Tang Jiao Gao Yongwan Park 

作者机构：Department of Biomedical Engineering Dalian University of Technology Dalian China Department of Information and Communication Engineering Yeungnam University Seoul South Korea 

出 版 物：《Journal of Biomedical Science and Engineering》 (生物医学工程（英文）)

年 卷 期：2013年第6卷第1期

页      面：65-75页

学科分类：1002[医学-临床医学] 100201[医学-内科学(含：心血管病、血液病、呼吸系病、消化系病、内分泌与代谢病、肾病、风湿病、传染病)] 10[医学] 

主　　题：Cardiopulmonary Modeling Systemic Hemodynamic Pulmonary Hemodynamic Timing of Heart Valve Closure Heart Sounds 

摘      要：This article investigates the relationships between heart valve closure timing intervals and left ventricular systolic blood pressure (LVSBP). For this investigation, the cardiopulmonary system is modeled as an analog circuit, including heart chambers, the distal and proximal aorta, distal and proximal systemic arteries/veins, systemic capillaries, the vena cava, the distal and proximal pulmonary artery, distal and proximal pulmonary arteries/veins, pulmonary capillaries and physiological control of heart rate and cardiac contractibility. In this model, the ventricles, atria and arteries were modeled as advanced pressur-volume relationships. A vagal-sympathetic mechanism was adopted to simulate transient systemic and pulmonary blood pressure. Four intervals, i.e., the timing interval between mitral and aortic valve closure (TIMA), the timing interval between aortic and mitral valve closure (TIAM), the timing interval be- tween aortic and pulmonary valve closure (TIAP) and the timing interval between mitral and tricuspid valve closure (TIMT), are further defined in a heart cycle to illustrate their relationships to LVSBP. Simula- tions showed that the TIMA, TIAM and TIAP have strong negative correlations with LVSBP;meanwhile, the TIMT has a slightly negative relationship with LVSBP. To further validate the relationships, 6 healthy male subjects were experimentally evaluated. The intervals were extracted from non-invasively sampled heart sound signals taken from the surface of the thorax. The experiments showed relationships consistent with those obtained by simulations. These relationships may have potential applications for noninvasively accessing LVSBP in real-time with a high time resolution of one heartbeat.