Makindo Medical Notes

Related Subjects: |Examining the Arterial Pulse |Examining the Jugular Venous Pressure (JVP)

Introduction

The Jugular Venous Pressure (JVP) is an important clinical indicator of right atrial pressure and central venous pressure. Examination of the JVP provides valuable information about a patient's hemodynamic status, particularly the function of the right side of the heart. The internal jugular vein is preferred for assessment due to its direct connection to the right atrium without intervening valves, allowing it to act as a manometer of right atrial pressure.

Anatomy of the Internal Jugular Vein

The internal jugular vein runs deep to the sternocleidomastoid muscle and lies between its sternal and clavicular heads. It originates at the jugular foramen at the base of the skull and descends within the carotid sheath alongside the internal carotid artery (above) and common carotid artery (below), and the vagus nerve. The absence of valves between the internal jugular vein and the right atrium allows for direct transmission of right atrial pressure changes.

Technique of JVP Examination

• Patient Positioning:
  • Position the patient reclining at a 45-degree angle with the head turned slightly to the left to expose the right side of the neck.
  • Ensure the patient's neck muscles are relaxed; a pillow can be used for support.
• Lighting:
  • Use tangential lighting to enhance visualization of the venous pulsations.
• Identification:
  • Locate the pulsations of the internal jugular vein between the two heads of the sternocleidomastoid muscle.
  • Avoid confusion with the external jugular vein, which is more superficial and less reliable for assessing right atrial pressure due to the presence of valves.
• Measurement:
  • Measure the vertical height of the venous pulsation above the sternal angle (angle of Louis), which is approximately 5 cm above the right atrium in all positions.
  • Normal JVP is ≤3 cm above the sternal angle (≤8 cm above the right atrium when adding the 5 cm from the sternal angle to the right atrium).

Differentiating JVP from Carotid Pulse

Feature	Internal Jugular Vein (JVP)	Carotid Artery
Palpability	Not palpable	Palpable
Number of Waveforms	Double waveform (a and v waves)	Single waveform
Effect of Position	Varies with position; decreases when sitting upright	Unaffected by position
Effect of Respiration	Decreases with inspiration	Unaffected by respiration
Compression	Can be occluded with gentle pressure at the base of the neck	Cannot be occluded
Abdominojugular Reflux	Rises with abdominal pressure	No change with abdominal pressure

Inspecting the Jugular Venous Pulse

• Height Measurement: Use a centimeter ruler or card aligned horizontally from the top of the venous pulsation to a ruler placed vertically at the sternal angle.
• Absent Pulsations: If the JVP is not visible, consider:
  • Hypovolemia: Decreased blood volume can make the JVP difficult to assess.
  • Superior Vena Cava (SVC) Obstruction: Non-pulsatile distention of neck veins with possible facial swelling and venous collaterals on the chest wall.
• Abnormal Respiratory Variation: Normally, the JVP decreases with inspiration due to decreased intrathoracic pressure. A paradoxical rise (Kussmaul's sign) suggests constrictive pericarditis or right ventricular dysfunction.

Understanding the JVP Waveform

The JVP waveform reflects right atrial pressure changes during the cardiac cycle. It consists of positive waves and descents:

Waveform Component	Description	Physiological Cause
a-wave	First positive deflection during atrial contraction	Atrial contraction propelling blood into the right ventricle
c-wave	Small positive deflection following the a-wave	Bulging of the tricuspid valve into the right atrium during ventricular contraction
x descent	Downward deflection after the c-wave	Atrial relaxation and downward displacement of the tricuspid valve during ventricular systole
v-wave	Second positive deflection during late systole	Passive filling of the right atrium against a closed tricuspid valve
y descent	Downward deflection following the v-wave	Opening of the tricuspid valve and rapid ventricular filling

Pathological JVP Waveforms

Abnormalities in the JVP waveform can indicate specific cardiac conditions:

Abnormal Waveform	Description	Associated Conditions
Cannon a-waves	Large amplitude a-waves due to atrial contraction against a closed tricuspid valve	Complete heart block, ventricular tachycardia, junctional rhythms
Absent a-waves	Loss of a-wave component	Atrial fibrillation (lack of coordinated atrial contraction)
Prominent v-waves	Increased amplitude of the v-wave	Tricuspid regurgitation (backflow of blood into the right atrium during systole)
Steep y descent	Rapid and deep y descent	Constrictive pericarditis, severe right heart failure
Slow y descent	Prolonged y descent	Tricuspid stenosis, right atrial myxoma
Kussmaul's Sign	Paradoxical rise or lack of decrease in JVP during inspiration	Constrictive pericarditis, restrictive cardiomyopathy, right ventricular infarction

Causes of Abnormal JVP Height

JVP Finding	Description	Common Causes
Raised JVP	Elevation of the JVP above normal levels	Right Heart Failure: Inability of the right ventricle to pump effectively Fluid Overload: Excessive intravenous fluids, renal failure Constrictive Pericarditis: Thickened pericardium restricting heart expansion Cardiac Tamponade: Accumulation of fluid in the pericardial sac compressing the heart Tricuspid Valve Disease: Regurgitation or stenosis impeding blood flow Pulmonary Hypertension: Elevated pressure in the pulmonary circulation increasing right ventricular afterload Superior Vena Cava Obstruction: Obstruction impeding venous return to the heart
Low JVP	JVP not visible or significantly below normal levels	Hypovolemia: Decreased circulating blood volume due to dehydration, hemorrhage Septic Shock: Vasodilation and fluid loss leading to low venous pressure End-Stage Heart Failure: Severe left ventricular dysfunction reducing overall cardiac output

Additional Clinical Maneuvers

• Abdominojugular Reflux (Hepatojugular Reflux):
  • Apply firm pressure over the right upper quadrant of the abdomen for 10 seconds.
  • A positive test is a sustained rise in the JVP of ≥3 cm, indicating right heart failure or elevated right atrial pressure.
• Respiratory Variation:
  • Observe changes in the JVP with respiration; normal response is a decrease during inspiration.

Clinical Significance

Accurate assessment of the JVP can aid in diagnosing and managing a variety of cardiovascular conditions. It provides insights into:

• Volume Status: Differentiating between hypovolemia and fluid overload.
• Right Heart Function: Identifying right ventricular failure or tricuspid valve pathology.
• Pericardial Diseases: Detecting constrictive pericarditis or cardiac tamponade.
• Pulmonary Hypertension: Recognizing elevated pulmonary pressures affecting the right heart.
• Superior Vena Cava Syndrome: Identifying obstruction in the venous return to the heart.

Conclusion

Examination of the Jugular Venous Pressure is a valuable clinical skill that provides non-invasive insights into a patient's hemodynamic status. Mastery of the technique and interpretation of findings can significantly enhance diagnostic accuracy and patient care in cardiovascular medicine.

References

• Bickley LS, Szilagyi PG. Bates' Guide to Physical Examination and History Taking. 12th ed. Wolters Kluwer; 2017.
• Kasper DL, Fauci AS, Hauser SL, et al., editors. Harrison's Principles of Internal Medicine. 20th ed. McGraw-Hill; 2018.
• Epstein O, Perkin GD, Cookson J, de Bono DP. Clinical Examination. 4th ed. Mosby; 2008.
• Seidel HM, Ball JW, Dains JE, Benedict GW. Mosby's Guide to Physical Examination. 7th ed. Elsevier; 2011.
• McGee S. Evidence-Based Physical Diagnosis. 4th ed. Elsevier; 2018.
• Butman SM, Goldberg RJ. The Jugular Venous Pressure Revisited. Cleve Clin J Med. 2010;77(5):312-320.