The term peripheral vascular signs refers to changes in the pulsation or waveform of the blood vessels found on examination of the peripheral vessels in certain disease conditions. Common clinical signs of peripheral vascularity include capillary pulsation, watery pulse, alternating pulse, heavy pulse, odd pulse, flooding pulse, thin pulse, gunshot sound, and Duroziez double sound. So what is the pathogenesis of the change in vascular pulsation or waveform? 1. Since there are various manifestations of peripheral vascular signs, the mechanism of their occurrence varies. The most common disease that leads to the appearance of peripheral vascular signs is aortic valve insufficiency. When the aortic valve is not closed, the heart compensates for the enhanced contraction so that there is enough blood in the aorta and even the small arteries of the body during the systolic period, so that the systolic pressure rises, the pulse is strong and powerful, and the flooding pulse appears. In the diastolic phase of the heart, due to incomplete closure of the aortic valve, a large amount of blood in the aorta regurgitates into the left ventricle, causing compensatory contraction of the aorta, small arteries and capillaries, thus increasing the difference between the systolic and diastolic pressure of the arteries and forming a series of peripheral vascular signs such as water rushing pulse, gunshot sound, Duroziez double sound and capillary pulsation sign. 2, when there is shock, aortic stenosis and some other diseases, the cardiac blood volume decreases, can appear fine pulse, due to the circulation blood volume is insufficient to cause the reduction of intravascular blood flow small alternating pulse is the result of alternating strength of ventricular contraction, as a manifestation of myocardial damage, seen in severe hypertensive heart disease and coronary artery atherosclerotic heart disease. The mechanism of the odd pulse is more complex and is commonly seen in pericarditis, which is an important sign of pericardial tamponade. Under normal circumstances, the blood volume of the pulmonary circulation increases during inspiration, but the perfusion of the body circulation to the right heart increases accordingly, so that the blood volume of the pulmonary circulation returning to the left heart does not change significantly, making the change in pulse size also insignificant. However, in the case of pericardial tamponade, although the volume of pulmonary blood increases during inspiration, the volume of blood returning to the left heart from the pulmonary circulation cannot increase correspondingly due to restricted ventricular diastole, resulting in a decrease in the volume of blood returning to the left heart from the pulmonary circulation and a decrease in the volume of blood ejected from the left ventricle, making the pulse weak or even not palpable, i.e., forming an odd pulse. 3, arteriovenous ductus arteriosus, aortic valve closure insufficiency, obstructive hypertrophic cardiomyopathy and other diseases can appear heavy pulsation pulse, and peripheral vascular tension decreased perinatal resistance is reduced and other factors.