Venous Pulse: Definition, Anatomy, Physiology, Indications, Technique, Abnormalities and Effects

Jugular venous pressure reflects the pressure in the right atrium (central venous pressure).

Venous pressure is estimated to be the vertical distance between the top of the blood column (highest point of oscillation) and the right atrium.

Anatomy

Right and left internal jugular veins

  • The larger paired neck veins that drain the head and neck.
  • They originate in the dural venous sinuses.
  • They exit the skull through the jugular foramen.
  • They go down the neck alongside the internal carotid arteries.
  • It joins the subclavian veins at the base of the neck.
  • Located posterior and superior to the medial quarter of the clavicle, in a cephalad direction until it passes under the sternocleidomastoid muscle.
  • They are not directly visible, identifiable only through pulsations transmitted to the surface of the neck.

Right internal jugular vein

  • It communicates directly with the right atrium through the superior vena cava.
  • Right and left external jugular veins.
  • Drain the superficial scalp and facial structures.
  • As they descend through the lateral neck, they pass diagonally over the top of the sternocleidomastoid muscles.
  • They empty into the subclavian veins.

Louis sternal angle

The bony ridge adjacent to the second rib where the manubrium joins the body of the sternum.

Stays approximately 5 cm above the right atrium regardless of the patient’s position

Physiology

Pressure changes due to filling, contraction, and emptying of the right atrium cause fluctuations in jugular venous pressure and its waveforms that are visible to the examiner.

Indications

Routine cardiac examination in the evaluation of:

  • Pericarditis constrictiva.
  • Heart failure.
  • Pericardial taponamiento.
  • Pulmonary hypertension.
  • Obstruction of the superior vena cava.
  • Tricuspid stenosis.

To determine central venous pressure

Jugular Venous Pulse Exam

The two main objectives of the bedside examination of the neck veins are the estimation of the central venous pressure and the inspection of the waveform.

The right internal jugular vein is usually superior for both purposes. In most normal subjects, the maximum pulsation of the internal jugular vein is seen when the trunk is inclined by less than 30 °.

In patients with elevated venous pressure, it may be necessary to elevate the trunk further, sometimes up to 90 °. When the neck muscles are relaxed, the brightness of a tangent beam of light on the skin overlying the internal jugular vein exposes their pulsations.

Simultaneous palpation of the left carotid artery helps the examiner decide which pulsations are venous.

Technique

It begins with the patient relaxing comfortably in bed, with the head on a pillow (to relax the sternocleidomastoid muscles), the view of the neck and chest should be unobstructed (if possible), and the head of the bed elevated 30 ° to 45 °.

Turn the patient’s head slightly away from the side you are inspecting and extend the chin (make sure the sternocleidomastoid muscles are still relaxed).

Use tangential light to identify the external jugular veins and then the internal pulsations of the jugular vein (lower half of the neck). If jugular venous pulsations cannot be seen, the head of the bed is lowered / raised until it is observed.

Care must be taken to distinguish internal jugular pulsations from carotid artery pulsations. The pulsations on the right side of the neck should be observed while measuring the pulse of the carotid artery on the left side of the neck with the examiners of the right third finger.

Observe whether the left and right jugular veins dilate to approximately the same degree of elevation during the same phase of breathing.

Observe the fluttering waves on inspiration and expiration (this identifies the upper part of the venous column). To find the top of the column, the head of the bed may need to be raised and lowered several times.

Avoid overbreathing or holding your breath because it distorts the normal mean venous pressure.

Focus on the right internal jugular vein and look for pulsations in the suprasternal notch.

Identify the highest point of pulsation. Extend a long rectangular card / ruler horizontally from this point and a centimeter ruler vertically from the sternal angle (make an exact right angle).

Measure the vertical distance (in centimeters) over the sternal angle where the horizontal letter crosses the ruler. Add to this distance 4 cm (the distance from the sternal angle to the center of the right atrium).

Evaluation of the venous pulse is an integral part of the physical examination, as it reflects both mean right atrial pressure and hemodynamic events in the right atrium.

Factors influencing right central venous and atrial pressure include total blood volume, blood volume distribution, and right atrial contraction. Venous blood returning from systemic capillaries is not pulsatile.

Changes in flow and pressure caused by skeletal muscles and the respiratory pump are not synchronized with the pulsatile activity of the heart.

However, changes in flow and pressure caused by right ventricular and atrial filling produce pulsations in the central veins that are transmitted to the peripheral veins, opposite to the direction of blood flow.

With the possible exception of the “c” wave, which is the combined result of carotid arterial impact and upward motion of the tricuspid valve, the pulsations observed in the neck are produced by the right atrium and ventricular activity.

Venous pressure measurement

The difference between venous distention and elevation of venous pressure should be considered. Veins may be markedly dilated with minimal pressure rise or may not be visible distended despite very high venous pressure.

Venous pressure can be estimated by examining the veins on the back of the hand. With a patient lying or sitting at an elevation of 30 ° or more, the arm is slowly and passively raised from a dependent position.

When venous pressure is normal, the veins collapse when the back of the hand reaches the level of the angle of Louis. Unfortunately, local venous obstruction or increased peripheral venous constriction can decrease the accuracy of the central venous pressure estimation by this method.

The external or internal jugular vein can also be used to estimate venous pressure. Due to its more direct route to the right atrium, the internal jugular vein is superior for venous pressure estimation and venous waveform evaluation.

The patient is examined in the optimal degree of trunk elevation to visualize venous pulsations. The vertical distance from the top of the oscillating venous column to the level of the sternal angle is generally less than 3 cm. (3 cm + 5 cm) = 8 cm).

Elevated venous pressure can be missed by not adequately elevating the patient’s head. It may be necessary to make the patient sit upright.

If the “pulsating meniscus” is very high, the pulsations may be inappropriate in the lower neck. When venous congestion is marked, the patient’s earlobe may pulse and even the veins on the top of the head may be distended.

In patients with suspected right ventricular failure but with normal resting venous pressure, the abdominojugular (also known as hepatojugular) test is useful.

With the patient breathing normally, firm pressure is applied with the palm of the hand toward the right upper quadrant of the abdomen for 10 seconds or more. The patient should be instructed to continue breathing normally during the test.

In most subjects, venous pressure is not significantly altered. In some normal patients, there is a transient increase in jugular venous pressure with “rapid return” to or near baseline in less than 10 seconds.

However, the dysfunctional right ventricle is unable to accept the increased blood volume due to venous enlargement without a marked increase in its filling pressure, which is transmitted to the neck veins.

In patients with right ventricular failure, which often results from left heart failure, venous pressure rises rapidly and slowly decreases during abdominal compression or remains elevated in 4 or more centimeters of blood until pressures are released.

Analysis of venous waveforms

Again, the patient’s trunk should be tilted to whatever elevation is necessary to reveal the upper part of the oscillating venous column.

Having the patient take a slow, deep inspiration will increase the amplitude of the presystolic ‘a’ wave while decreasing the mean right atrial pressure.

This is a useful technique for identifying where your keystrokes will be best viewed. Simultaneous palpation of the left carotid artery helps the examiner to relate the venous pulsations to the time of the cardiac cycle.

The normal venous pulse reflects phasic pressure changes in the right atrium and consists of three positive waves and negative channels.

When considering this pulse, it is helpful to refer to the events of the cardiac cycle. The positive presystolic “a” wave is produced by contraction of the right atrium and is the dominant wave in the normal venous pulse, particularly during inspiration.

During atrial relaxation, the venous pulse descends from the top of the “a” pathway. Depending on the PR interval, this decline may continue until reaching a plateau (“z” point) just before right ventricular systole.

Most often, the descent is interrupted by a second positive venous wave, the «c» wave, which is produced by bulging of the tricuspid valve in the right atrium during right ventricular isovolumic systole and by the impact of the crowded artery. adjacent to the jugular vein.

After the peak of the «c» wave, the normal venous pulse contour decreases, forming the normal negative systolic wave, the «x» wave. The “x” descent is due to a combination of atrial relaxation, downward displacement of the tricuspid valve during right ventricular systole, and expulsion of blood from both ventricles.

The positive late systolic “v” wave in the normal venous pulse results from increased blood volume in the vena cavae and right atrium during ventricular systole when the tricuspid valve is closed.

After reaching the peak of the “v” wave, right atrial pressure decreases due to decreased bulging of the tricuspid valve in the right atrium and decreased right ventricular pressure that follows the opening of the tricuspid valve.

The latter occurs at the peak of Wave «v» in jugular venous pressure.

After the summit of the «v» wave, there is a negative descending limb, known as the «y» descent or diastolic collapse, which is due to the opening of the tricuspid valve in the rapid and flow of blood towards the right ventricle.

The initial descent “y” corresponds to the right ventricular rapid filling phase. Depression of the “y” wave occurs in early diastole and is followed by the ascending limb of the “y” wave, which is produced by the continuous flow of diastolic blood to the right side of the heart.

The speed of this rising pressure curve depends on the rate of venous return and the compliance of the chambers on the right side of the heart.

When diastole is long, the downward end of the “y” wave is often followed by a small, short, positive wave, the “h” wave, which occurs just before the next “a” wave.

Sometimes there is a plateau phase instead of a different “h” wave. With increasing pulse rate, the “y” channel and the “y” rise are immediately followed by the next “a” wave.

Generally, there are three main positive waves visible (“a”, “c”, “v”) and two negative waves (“x”, “y”) when the pulse rate is less than 90 beats per minute and the PR interval is normal.

With faster heart rates, there is often fusion of some of the pulse waves and accurate analysis of the waveform is more difficult.

Abnormal venous pulse

Elevated venous pressure

The most common cause of jugular vein elevation as pressure is an increase in right ventricular pressure, as occurs in patients with pulmonary stenosis, pulmonary hypertension, or right ventricular failure secondary to right ventricular infarction.

Venous pressure also rises when right ventricular inflow obstruction occurs, as with tricuspid stenosis or right atrial myxoma, or when constructive pericardial disease prevents right ventricular inflow.

It can also be the result of an obstruction of the vena caval and sometimes an increase in blood volume. Patients with obstructive pulmonary disease may have elevated venous pressure only during expiration.

Kussmaul’s sign

There is usually an increase in the “a” wave of the normal venous pulse, but a decrease in mean jugular venous pressure during inspiration as a result of increased filling of the right-side chambers associated with decreased intrathoracic pressure.

An inspiratory increase in venous pressure can occur in patients with severe constrictive pericarditis when the heart cannot accept the increase in right ventricular volume without a marked increase in filling pressure.

Although Kussmaul’s sign was first described in patients with constructive pericarditis, its most common cause is severe right-sided heart failure, regardless of its etiology. The presence of Kussmaul’s sign is also useful in the diagnosis of right ventricular infarction.

«A» wave abnormalities

The “a” wave in the normal venous pulse is absent when there is no effective atrial contraction, as in atrial fibrillation. Under certain other conditions, the “a” wave may not be apparent.

In sinus tachycardia, the “a” wave may merge with the preceding “v” wave, particularly if the PR interval is prolonged.

In some patients with sinus tachycardia, the “a” wave may occur during the “v” or “y” descent and may be small or absent. In the presence of first-degree AV block, a discrete “a” wave with ascending and descending limbs often completes before the first heart sound, and the AC interval is prolonged.

Large “a” waves have considerable diagnostic value. When giant “a” waves are present with each beat, the right atrium contracts against increased resistance.

This can result from tricuspid valve obstruction (tricuspid stenosis or atresia, right atrial myxoma, or conditions associated with increased resistance to right ventricular filling.

A giant “a” wave is more likely to occur in patients with pulmonary stenosis or pulmonary hypertension in whom both the atrial and right ventricular septums are intact.

The cannon “a” waves are produced when the right atrium contracts while the tricuspid valve closes during right ventricular systole. Cannon waves can occur regularly or irregularly and are more common in the presence of arrhythmias.

“X” wave abnormalities

The most important alteration of the normally negative systolic collapse (“x” wave) of the pulse is its obliteration or even replacement by a positive wave.

This is usually due to tricuspid regurgitation. Although atrial relaxation may contribute to the normal “x” descent, the development of atrial fibrillation does not destroy the “x” wave except in the presence of tricuspid regurgitation.

Consequently, the appearance of a positive JVP wave during ventricular systole is strong evidence of tricuspid regurgitation. mild tricuspid regurgitation decreases and shortens the descending “x” wave as regurgitation of blood into the right atrium produces a positive wave that decreases the usual systolic drop in venous pressure.

In some patients with moderate tricuspid regurgitation, there is quite a distinct positive wave during ventricular systole between the “c” and “v” waves.

This abnormal systolic waveform is generally referred to as a “v” or “cv” wave, although it has also been called an “r” (regurgitant) or “s” (systolic) wave.

In patients with constricted pericarditis, the downward “x” wave during systole is often more prominent than the early diastolic “y” wave.

Wave «v» abnormalities.

The positive late systolic “v” wave results from increased right atrial blood volume during ventricular systole when the tricuspid valve is normally closed.

With mild tricuspid regurgitation, the “v” wave becomes more prominent, and when tricuspid regurgitation becomes severe, the prominent “v” wave and obliteration of the “x” descent result in a single large positive systolic wave (ventricularization) .

Normally, the “v” wave has a lower amplitude than the “a” wave in the normal venous pulse. However, in patients with an ASD, the higher left atrial pressure is transmitted to the right atrium, and the “a” and “v” waves are often the same in the right atrium and the normal venous pulse.

In patients with constrictive pericarditis and sinus rhythm, the right atrial “a” and “v” atrial waves may also be the same, but venous pressure increases, which is unusual with an isolated atrial septal defect.

In patients with constrictive pericarditis who are in atrial fibrillation, the “cv” wave is prominent and the “y” descent is rapid.

Channel abnormalities “y”

The “y” dip, or diastolic collapse, is usually caused primarily by the opening of the tricuspid valve and the rapid flow of blood into the right ventricle.

There is a rapid deep “y” descent in early diastole with severe tricuspid regurgitation. A venous pulse characterized by a sharp “y” and a rapid rise to baseline is seen in patients with constrictive pericarditis. or with severe heart failure on the right side.

A slow “Y” decrease in normal venous pulse suggests right ventricular filling obstruction and may be the only abnormal finding in patients with tricuspid stenosis or right atrial myxoma.

In both constrictive pericarditis and severe right-sided heart failure, venous pressure rises with a sharp “Y” drop. The presence of a large positive systolic venous wave favors the diagnosis of severe heart failure.

Effects of Venous Pulse Arrhythmias

The large “a” waves in the normal venous pulse during arrhythmias are present when the P wave occurs between the onset of the QRS complex and the determination of the T wave.

Such “a” cannon waves can occur regularly in junctional rhythm. Most commonly, they occur irregularly when AV dissociation accompanies premature ventricular contractions, ventricular tachycardia, or complete heart block.

The “a” wave is absent in patients with atrial fibrillation, and “a” flutter at a regular rate of 250–300 per minute is frequently seen in patients with atrial flutter and varying degrees of AV block.

Patients with multifocal atrial tachycardia often have prominent and somewhat variable “a” waves in the venous pulse. In these patients, many of whom have pulmonary hypertension secondary to lung disease, the “a” waves are usually very large.