Jugular Venous Pressure (JVP) Pulsations

Jugular Venous Pressure ( JVP ) Pulsations

· Jugular Venous Pressure tells us about the right atrial and right ventricular function. Besides that, we can derive information such as mean venous pressure, venous pulse contour and the presence and type of cardiac dysarythmias.

· Technique :

o Positioning of the patient – lying down at 45 degrees to the horizontal with his or head on pillows and in good lighting condition ( directed tangentially at approximately 45 degrees across the right side of the neck towards the midline ).

§ The internal jugular vein is deep to the sternocleidomastoid while the external jugular vein lies lateral to it. Usually, the right internal and external jugular veins give consistent readings. However, left sided veins are less accurate because they cross from the left side of the chest before entering the right atrium. Pulsations that occur in the right sided veins reflect movements of the top of a column of blood that extends directly into the right atrium. It may be used as a manometer and enables us to observe pressure changes in the right atrium.

o The sternal angle which is taken as the zero point from which it is used to measure the vertical height of the column of blood in the jugular vein in centimeters should be noted when the patient is lying at 45 degrees.

o Usually the patient's chin must be extended to enhance this observation. But care should be exercised so that the sternocleidomastoid muscle is not excessively tensed, thus compressing the external and internal jugular veins and obliterating their pulsations. It is crucial that the examiner be certain to distinguish between venous and arterial pulsations, and that the top of the venous column is recognized. The former is accomplished by seeking the three crests in the venous pulse and comparing them to the carotid arterial pulse. Apparently, it is easiest to observe the pulsations in the right side of the neck while timing the carotid pulse in the left side of the patient's neck using the right third finger. If still uncertain as to whether or not you are observing the venous pulse, you could try to obliterate the venous pulse by placing your right thumb or index finger across the base of the patient's right neck. By compressing this area with a force of approximately 10 to 20 mm Hg, the venous pulse can be obliterated.

o The jugular venous pulse can be distinguished from the arterial pulse because :

§ It is visible but not palpable

§ It has a complex wave form, usually seen to flicker twice with each cardiac cycle ( if the patient is in sinus rhythm)

§ It moves on with respiration – JVP usually decreases on inspiration

§ It is at first obliterated and then filled from above when light pressure is applied at the base of the neck.

o The JVP must be accessed in height and character.

o The next step is to determine the height of the mean jugular venous pressure, measured in centimeters of water, above the midpoint of the right atrium.. To determine the mean jugular venous pressure, the examiner should observe the nadir of the venous column on inspiration and then the crest of this column on expiration. Next, the midpoint of the excursion of the venous pulse during normal respiratory cycles is estimated visually. Exaggerated breathing or breath holding distorts the normal mean venous pressure and should be avoided. A horizontal line is drawn from this estimated point to intersect a vertical line, which is erected perpendicular to the ground through the sternal angle of Louis. The distance between the sternal angle and this intercept is measure. The sum of this distance—plus the obligatory 5-cm fixed relationship to the midpoint of the right atrium—represents the mean jugular venous pressure.

§ When the JVP is more than 3 cm above the zero point, the right heart filling pressure is raised ( a normal reading is less than 8 cm of water : 5 cm+3 cm = 8 cm). This is a sign of right ventricular failure, volume overload or some types of pericardial disease.

· The assessment of character.

· There are two positive waves in the normal JVP. The first is called an ‘a’ wave and coincides with the right atrial systole. It is due with atrial contraction. The second impulse is called a ‘v’ wave and is due to atrial filling, in the period where the tricuspid valve remains closed during the ventricular systole.

Between the ‘a’ and ‘v’ waves there is a trough caused by atrial relaxation. This is called the x descent. It is interrupted by the c point, which is due to transmitted carotid pulsation and coincides with tricuspid valve closure. It is not usually visible. Following the v wave, the tricuspid valve opens and rapid ventricular filling occurs; this results in the ‘y’ descent.

· Any condition in which the right ventricular filling is limited can cause the elevation of venous pressure in which is more marked in inspiration when venous return to the heart increases. The rise in JVP on inspiration is called the Kussmaul’s sign. Sign is best elicited with the patient sitting up at 90 degrees and patient breathing quietly.

· Abdominojugular reflux test is a way of testing for left ventricular failure or reduced right ventricular compliance. Pressure exerted over the liver or middle of the abdomen for 10 seconds will increase venous return to the right atrium, The JVP usually rises following this manouevere.

Wave form	Causes
Dominant ‘a’ wave	Tricuspid stenosis ( also causes a slow y descent), Pulmonary stenosis, Pulmonary hypertension
Cannon ‘a’ waves	Complete heart block, Paroxymal nodal tachycardia with retrograde atrial conduction, Ventricular tachycardia with retrograde atrial conduction or atrioventricular dissociation
Dominant ‘v’ wave	Tricuspid regurgitation
X descent	Absent : Atrial Fibrillation Exaggerated : Acute cardiac tamponade, constrictive pericarditis
Y descent	Sharp : Severe tricuspid regurgitation, constrictive pericarditis Slow : Tricuspid stenosis, right atrial myxoma