The Jugular Venous Pressure and Pulse Contour
The Jugular Venous Pressure and Pulse Contour
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颈静脉压和脉搏轮廓
DOI：
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发表时间：
1990
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通讯作者：
M. M. Applefeld
中科院分区：
文献类型：
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作者：
M. M. Applefeld
通过评估颈静脉脉搏可以获得的信息包括平均静脉压、静脉脉搏轮廓以及心律失常的存在和类型。颈静脉压通常是通过观察患者右侧颈部来评估的。正常平均颈静脉压为6~8cmH2O，以右心房中点上方垂直距离为标准。偏离这一正常范围反映血容量不足(即平均静脉压低于5厘米水)或心脏充盈受损(即平均静脉压大于9厘米水)。正常的颈静脉脉搏包含三个正波。按照惯例，它们被标记为“a”、“c”和“v”(图19.1)。这些正偏转分别发生在颈动脉上升之前和紧接在心电P波之后(a波)；与颈动脉脉搏上升同时发生(c波)；以及在三尖瓣打开之前的心室收缩期间(v波)。A波是由心房收缩产生的，它在舒张末活跃地充盈右心室。C波是由于颈动脉冲动通过颈外静脉和颈内静脉的传递，或者是由于三尖瓣在收缩早期膨胀到右心房而引起的。V波反映了右心房在收缩晚期和舒张期充盈时压力和容量的被动增加。正常情况下，a波和v波的波峰在幅度上大致相等。颈静脉脉搏的下降或波谷(图19.1)出现在“a”和“c”波之间(“x”下降)，“c”和“v”波之间(“x”下降)，以及“v”和“a”波之间(“y”下降)。X和x‘下降反映了在心室收缩的最后阶段，右心房下部向右室移动。Y下降代表在三尖瓣打开和右室开始被动充盈后，舒张期早期v波的下击突然终止。正常情况下，y下降既不像x下降那么快，也不像x下降那么深。颈静脉脉搏的异常可反映在平均压力、幅度、正波或负波或波谷的形态，或正波序列或无正波。本章重点介绍颈静脉压的测量，利用静脉脉搏来确定心率，以及更常见的心脏问题，如肺动脉高压、三尖瓣返流和缩窄性心包炎。
Information that can be derived from an assessment of the jugular venous pulse includes determination of the mean venous pressure, venous pulse contour, and presence and type of cardiac dysrhythmias . The jugular venous pressure is usually assessed by observing the right side of the patient's neck. The normal mean jugular venous pressure, determined as the vertical distance above the midpoint of the right atrium, is 6 to 8 cm H 2O . Deviations from this normal range reflect either hypovolemia (i .e ., mean venous pressure less than 5 cm H 2O) or impaired cardiac filling (i .e ., mean venous pressure greater than 9 cm H 2O). The normal jugular venous pulse contains three positive waves . By convention these are labeled "a," "c," and "v" (Figure 19 .1) . These positive deflections occur, respectively, before the carotid upstroke and just after the P wave of the ECG (a wave) ; simultaneous with the upstroke of the carotid pulse (c wave) ; and during ventricular systole until the tricuspid valve opens (v wave) . The a wave is generated by atrial contraction, which actively fills the right ventricle in end-diastole . The c wave is caused either by transmission of the carotid arterial impulse through the external and internal jugular veins or by the bulging of the tricuspid valve into the right atrium in early systole . The v wave reflects the passive increase in pressure and volume of the right atrium as it fills in late systole and early diastole . Normally the crests of the a and v waves are approximately equal in amplitude. The descents or troughs (Figure 19 .1) of the jugular venous pulse occur between the "a" and "c" wave ("x" descent), between the "c" and "v" wave ("x` descent), and between the "v" and "a" wave ("y" descent). The x and x' descents reflect movement of the lower portion of the right atrium toward the right ventricle during the final phases of ventricular systole . The y descent represents the abrupt termination of the downstroke of the v wave during early diastole after the tricuspid valve opens and the right ventricle begins to fill passively. Normally the y descent is neither as brisk nor as deep as the x descent. Abnormalities in the jugular venous pulse may be reflected in either the mean pressure, amplitude, or configuration of the positive waves or negative troughs, or in the sequence or absence of the positive waves . In this chapter emphasis is placed on measurement of the jugular venous pressure, use of the venous pulse to determine cardiac rhythm, and the more common cardiac problems of pulmonary hypertension, tricuspid regurgitation, and constrictive pericarditis .