尽管由于心导管、心血管造影、心内心音图及超声心动图应用的结果,使人们对心脏生理的认识有了显著进步,但在心音产生机制方面,却较之以前争论更大了。第一心音:关于第一心音产生方面有两大学说。一种是赞同经典的理论,即第一心音的主要成分是由房室瓣关闭时振动引起。按照这种理论,构成第一心音的两组高频振动与二尖瓣、三尖瓣的关闭有关,因之相应地称 Although cardiac catheterization, cardiovascular angiography, intracardiac echocardiography and echocardiographic applications have led to significant advances in understanding of cardiac physiology, there is much greater debate about the mechanism of heart sound production than before. First heart sound: There are two universities on the first heart sound. One is in favor of the classic theory that the primary component of the first heart sound is caused by vibration when the atrioventricular valve is closed. According to this theory, the two sets of high-frequency vibrations that constitute the first heart sound are related to the closure of the mitral and tricuspid valves, and accordingly