Introduction

  • The internal jugular vein is in direct communication, without intervening valves, with the Superior Vena Cava (SVC) and the right atrium. Its associative pressure changes are therefore a great indicator of the right atrial and ventricular function.

 

  • When the patient is standing/sitting up, the internal jugular vein is collapsed and when the patient is lying flat, it is completely filled.

 

  • The Jugular Venous Pressure (JVP) is found between the sternal and clavicular heads of the Sternoclavicular Muscle (SCM); usually just above the clavicle.

 

Procedure of Identifying the JVP

  • Position the patient at 45 degrees and ask them to turn their head to the left – Make sure neck muscles are relaxed since it enables the JVP to be more identifiable (a pillow may help).

 

  • If spotlight present, shine light on the neck to exaggerate any visible pulsations.

 

  • Differentiate the carotid artery from the JVP (table 1).  

 

 

Table 1

  • To confirm the presence of the JVP, exaggerate the pulsations through the conduction of the hepato-jugular reflux, which temporarily increases venous return to the right atrium. This can be done by gently pressing over the right upper quadrant of the abdomen for 10-15 seconds. Make sure the patient is not experiencing any abdominal pain before conducting this procedure, since you will lose marks in the OSCE if you hurt your patient.

 

  • Assess height:
    • This is done by measuring the vertical height from the manubriosternal angle to the top of the pulse. Pressure at zero (at the sternal angle) is 5cm, so add the height of the JVP with 5cm to obtain the right heart filling pressure in cm of water. A pressure above 9cm (4cm above the sternal angle at 45o) is reported as being elevated.  
    • Examine behind the ear if height of the JVP is grossly raised or if the JVP cannot be identified. 
  • Assess character (timing and waveform):
  •  
    • As illustrated by the figure 1, there are 5 main components in the JVP. Each component translates a specific stage in the cardiac cycle. Variations in the character of the JVP are thus a great method for uncovering any underlying cardiovascular pathology. 

 

Table 2

Illustration of the Different Waves in a Normal JVP Cycle

A = Right atrial systole: occurs immediately before carotid pulsation

C = Transmission of a rapidly increasing right ventricular pressure during tricuspid valve closure

X = Start of atrial relaxation during ventricular systole

V = Atrial diastole whilst tricuspid valve remains closed during ventricular systole: occurs at same time as carotid pulsation

Y = Tricuspid valves open and rapid ventricular filling occurs

 

Figure 1

Abnormalities in Waveform

Large ‘a’ Wave

This is due to ↑’d resistance to ventricular filling, which accordingly ↑'s pressure in the right atrium. Causes include:

  • Pulmonary hypertension (e.g. Pulmonary Embolism)
  • Tricuspid stenosis

 

Absent ‘a’ wave

This is seen in:

  • Atrial fibrillation

 

The irregularity of the rhythm prevents the differentiation of atrial contraction and relaxation and so the 'a' wave appears absent. 

    Cannon ‘a’ wave

    This is seen in:

    • Complete heart block

     

    This is due to the contraction of the right atrium against a closed tricuspid valve, which results in the generation of a high atrial pressure. 

       



      Large ‘v’ wave

      • Tricuspid regurgitation

       

      The 'v' wave represents atrial diastole, whereby the pressure in the right atrium is decreasing. However, during tricuspid regurgitation, the open valve fails to prevent the backflow of blood from the right ventricle during ventricular systole. This results in the rise in right atrial pressure. 



      Steep ‘y’ wave

      • Constrictive pericarditis

       

      Constrictive pericarditis restricts the adequate stretching of the cardiac wall. Subsequently, when the tricuspid valve opens, the pressure in the right atrium declines at a faster rate. 



      Special Signs

       

      Friedreich’s sign = the rapid fall and rise of the JVP (e.g. constrictive pericarditis)

      Kussmaul’s sign = ↑JVP on inspiration (e.g. constrictive pericarditis, cardiac tamponade)

       

      Both these signs are due to the restriction of the heart to adequately expand during the different stages of the cardiac cycle. Impaired right ventricular filling, in light of the increasing external pressure (cardiac tamponade) or pericardial limitation (constrictive pericarditis), results in the backlog of blood in to the right atrium and thus venous system. Accordingly a rise in JVP is visualised. This pattern is particularly accentuated during inspiration where there is an increased volume of venous blood entering the heart. 

      During cardiac tamponade in particular, three medical signs can be observed. These include:

       

      • Rise in JVP
      • Decreased arterial blood pressure
      • Muffled heart sounds on auscultation

       

      These features are collectively recognised as 'Beck's Triad'. Their presence should alert clinicians, since cardiac tamponade is a serious medical emergency. 

      Summary

      figure 5

      References

      1. Longmore M, Wilkinson I, Turmezei T & Cheung CK. Clinical Skills-The Jugular Venous Pressure. Oxford Handbook of Clinical Medicine. 7th Ed, pp30-31. United States: Oxford University Press Inc., 2009.
      2. Douglas G, Nicol F & Robertson C. The Cardiovascular System. Macleod's Clinical Examination. 12th Ed, pp124-126. Elesevier, 2009. 
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