Neck should not be sharply flexed. Using a centimeter ruler, measure the vertical distance between the angle of Louis manubrio sternal joint and the highest level of jugular vein pulsation. A straight edge intersecting the ruler at a right angle may be helpful. Cardiovascular Resources Videodisc If the internal jugular vein is not detectable, use the external jugular vein. The internal jugular vein is the preferred site. Palpable pulsations. Enhanced by the hepatojugular reflux see below.
Abnormalities of the a wave It disappears in atrial fibrillation. Large a waves occur in any cause of right ventricular hypertrophy pulmonary hypertension and pulmonary stenosis and tricuspid stenosis. Extra large a waves called cannon waves in complete heart block and ventricular tachycardia. Prominent v waves Tricuspid regurgitation - called cv or v waves and occurring at the same time as systole a combination of v wave and loss of x descent ; there may be earlobe movement.
Slow y descent Tricuspid stenosis. Right atrial myxoma. Steep y descent Right ventricular failure. Constrictive pericarditis. Tricuspid regurgitation. The last two conditions have a rapid rise and fall of the JVP - called Friedreich's sign. Are you protected against flu? Further reading and references. Join the discussion on the forums. Health Tools Feeling unwell? Assess your symptoms online with our free symptom checker. The IJV runs between the medial end of the clavicle and the ear lobe, under the medial aspect of the sternocleidomastoid, making it difficult to visualise its double waveform pulsation is, however, sometimes visible due to transmission through the sternocleidomastoid muscle.
However, because the EJV typically branches at a right angle from the subclavian vein unlike the IJV which sits in a straight line above the right atrium it is a less reliable indicator of central venous pressure. If a patient is hypervolaemic the JVP will appear raised due to increased venous pressure within the right atrium causing a higher than normal column of blood within the IJV. Differences between the venous pulsation of the JVP and the arterial pulsation of the carotid artery include:.
The double waveform pulsation associated with the JVP reflects pressure changes within the right atrium. Think of the pressure changes as a Mexican wave; starting in the right atrium and travelling to the IJV where we observe the pulsations. Ask the patient to turn their head slightly to the left. Inspect for evidence of the IJV, running between the medial end of the clavicle and the ear lobe, under the medial aspect of the sternocleidomastoid it may be visible just above the clavicle between the sternal and clavicular heads of the sternocleidomastoid.
The IJV has a double waveform pulsation, which helps to differentiate it from the pulsation of the external carotid artery. Measure the JVP by assessing the vertical distance between the sternal angle and the top of the pulsation point of the IJV in healthy individuals, this should be no greater than 3cm. The hepatojugular reflux test involves the application of pressure to the liver whilst observing for a sustained rise in JVP.
This test can be used to further assess the JVP, particularly if you are unsure if the vessel you are observing is the internal jugular vein. To be able to perform the test, there should be at least a 3cm distance from the upper margin of the baseline JVP to the angle of the mandible :.
A raised JVP indicates the presence of venous hypertension. Cardiac causes of a raised JVP include:. The A wave is caused by the contraction of the right atrium, where blood is being pumped through the tricuspid valve into the right ventricle. Increased pressure in the right atrium also forces blood upwards towards and into the IJV. This influx of venous blood into the IJV is known as the A wave.
The first part of the X descent is caused by relaxation of the right atrium , which results in blood filling the right atrium from the superior vena cava, reducing the height of the column of blood sitting in the IJV i. The right ventricles relaxation also contributes to the X descent, as blood exits the right atrium into the right ventricle, further reducing the column of blood in the SVC and IJV.
The C wave is caused by the forceful contraction of the right ventricle which ejects blood out of the heart into the pulmonary artery. As this occurs, the pressure within the right ventricle increases significantly, forcing the tricuspid valve upwards so much so that it projects partially into the right atrium.
This sudden projection of the tricuspid valve into the right atrium generates upwards force which is transmitted into the SVC and ultimately the IJV, causing a temporary rise in the JVP referred to as the C wave. The second part of the X descent occurs during the final phase of right ventricular contraction.
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