Smith D, Craige E
Br Heart J. 1986 Dec;56(6):531-4. doi: 10.1136/hrt.56.6.531.
The dicrotic pulse is an abnormal carotid pulse found in conjunction with certain conditions characterised by low cardiac output. It is distinguished by two palpable pulsations, the second of which is diastolic and immediately follows the second heart sound. In the course of open chest canine studies of the second heart sound, micromanometers and an electromagnetic flow meter were used to study proximal aortic haemodynamic function in both strong and weak beats. It was found that the incisural notch of the aortic pressure signal is not strongly dependent on the extent of left ventricular ejection, and is of essentially normal amplitude even in beats having greatly reduced aortic flow. In contrast, the magnitude of the systolic upstroke of the aortic pressure pulse is strongly determined by the magnitude of left ventricular ejection and is considerably reduced in weak beats. With low cardiac output the relative size of the incisural notch becomes exaggerated in comparison with the overall pulsation, thus creating the characteristic M shaped waveform of the dicrotic pulse.
重搏脉是一种异常的颈动脉搏动，见于某些心输出量降低的情况。其特征为可触及两次搏动，第二次为舒张期搏动，紧跟第二心音之后。在开胸犬的第二心音研究过程中，使用微测压计和电磁流量计来研究强弱搏动时主动脉近端的血流动力学功能。研究发现，主动脉压力信号的切迹并不强烈依赖于左心室射血程度，即使在主动脉血流大幅减少的搏动中，其幅度也基本正常。相比之下，主动脉压力脉搏的收缩期上升幅度强烈取决于左心室射血幅度，在弱搏动中会大幅降低。在心输出量较低时，切迹的相对大小与整体搏动相比会变得更加明显，从而形成重搏脉特有的M形波形。
