This requires that the dressing gown (preferrably opening to the patient's back) be positioned at the level of the nipples. Thus, the neck and chest must be bared to permit an unobstructed view from the midportion of the sternum to the antihelix of the ears. Nevertheless, attention to a few basic points is crucial for proper examination of the venous pulse.įirst, the patient must be positioned in a manner so that the physician can observe the venous pulse. Once understood and practiced in a repetitive manner during each physical examination, the mysticism surrounding assessment of the jugular venous pulse disappears. Normally the y descent is neither as brisk nor as deep as the x descent.Įvaluation of the jugular venous pulse is perhaps one of the most misunderstood and difficult to master physical diagnosis techniques. 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. 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 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). Normally the crests of the a and v waves are approximately equal in amplitude. The v wave reflects the passive increase in pressure and volume of the right atrium as it fills in late systole and early 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 a wave is generated by atrial contraction, which actively fills the right ventricle in end-diastole. 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). By convention these are labeled "a," "c", and "v" ( Figure 19.1). The normal jugular venous pulse contains three positive waves. 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 mean jugular venous pressure, determined as the vertical distance above the midpoint of the right atrium, is 6 to 8 cm H 2O. The jugular venous pressure is usually assessed by observing the right side of the patient's neck. 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.
0 Comments
Leave a Reply. |