Examination of jugular venous waveforms

INTRODUCTION — Examination of jugular venous waveforms is helpful in identifying a variety of cardiovascular disorders including right heart conditions, arrhythmias, and pericardial disease [1,2].

The approach to examination of jugular venous waveforms and identification of key abnormalities is discussed here. Analysis of the jugular venous pressure to estimate right atrial pressure is discussed separately. (See "Examination of the jugular venous pulse", section on 'Estimating right atrial pressure'.)

APPROACH TO EVALUATION

Examination of the jugular veins — Venous pulsations can be examined in the external or internal jugular veins. Examination of the jugular veins involves observing the venous pulsations at varying degrees of head and upper body elevation and with maneuvers to determine if there are abnormalities in the jugular venous waveform (figure 1).

Attention to a few key points is essential for proper examination of the jugular veins [1] (movie 1):

●Position – The examiner generally stands on the right side of the bed, as examination of the right side of the neck is generally preferred. (See "Examination of the jugular venous pulse", section on 'Which jugular vein to examine'.)

The patient lies supine upon an examination table or bed that bends in the middle at the hips to allow elevation and lowering of the entire upper body from head to thorax as a unit.

The patient's neck should be extended with sternocleidomastoid muscles relaxed; this is generally achieved with either a thin pillow or no pillow underneath the patient's head. Turn the head away (to the left if examining from the right) slightly (eg, 30 degrees from facing forward) and tip the head and jaw slightly up. This positioning may be guided by gentle pressure of the examiner's fingers on the patient's jaw to lift the jaw and neck upwards.

●Lighting – A helpful technique to improve visibility of the venous pulsations is to shine a flashlight tangentially to the skin over the mid portion of the neck (figure 1). The external jugular vein is generally visualized as it passes over the sternocleidomastoid muscle. To examine the internal jugular vein, the light is positioned so that a shadow is cast over the small shallow space between the sternal and clavicular attachments of the sternocleidomastoid muscle.

●Identifying venous pulsations – The upper part of the examination table or bed is raised to elevate the patient's head, neck, and thorax together as a unit with a bend at the hips. The degree of upper body elevation is the angle (0 to 90 degrees) at which the venous pulsations and venous meniscus is best appreciated along the neck. The optimal angle depends upon the level of the jugular venous pressure (JVP). Thus, it may be necessary to move the examination table or bed through various angles of upper body tilt until the pulsation is visible.

•Low JVP – Low venous pressures are best seen in or near a supine position (0 degree angle), while high JVPs are seen best with the patient sitting upright (90 degrees).

If venous pulsations are not visible with the patient in a supine position (0 degree angle), the following methods may enable identification of the pulsations, if clinically feasible [3]:

-Applying pressure with the tip of the examiner's index finger above the clavicle at the base of the neck to engorge the external jugular vein above the point of pressure.

-Asking the patient to perform a Valsalva maneuver to engorge the external jugular vein.

-Application of pressure for 10 seconds to the patient's abdominal right upper quadrant or mid upper abdomen to increase venous return and pressure. (See "Examination of the jugular venous pulse", section on 'Abdominojugular test'.)

-If the patient is hypovolemic with no visible JVPs at 0 degrees, the venous pulsations may be visible in the Trendelenburg (head tilted down) position.

•High JVP – Since it is important to detect a high JVP, we suggest always inspecting the neck with the patient sitting upright at some point during the examination. If the JVP is seen above the clavicle when the upper body is elevated to 90 degrees, the venous pressures are likely elevated [4]. A high JVP may be missed in the supine position as the pulsation may be hidden high up (superiorly) in the neck. In patients with a very high JVP, the pulsation can cause the lower part of the ear lobe to pulsate.

●Identifying waveform components – A strategy for identifying the waveform components described below is to initially focus on identifying the descents (x, x', and y) rather than the ascents (a, c, and v) [5]. (See 'Waveform components' below.)

Distinguishing venous from arterial pulsations — When examining internal or external jugular venous pulsations, the following characteristic are helpful in distinguishing venous from arterial pulsations [3]:

●Direction of movement – In jugular vein pulsations, the most prominent movement is inward (descent). This is most commonly visible as one or two inward movements per cardiac cycle. In the carotid arteries, there is one outward pulsation per cardiac cycle.

●Palpation – The carotid pulsations are palpable, in contrast to the jugular venous pulsations, which are not palpable in almost every scenario. The most common exception is in severe tricuspid regurgitation, when the venous pulse may be palpable.

●Effect of inspiration, position and abdominal pressure – Jugular venous pulsations in healthy individuals decrease with inspiration and sitting up, and they increase with upper abdominal pressure. Carotid artery pulsations not changed by inspiration, position, or abdominal pressure.

Paradoxical increase or lack of decrease in JVP with inspiration (Kussmaul sign) is associated with disease states, as discussed separately. (See "Examination of the jugular venous pulse", section on 'Respirophasic changes (Kussmaul sign)'.)

Other methods — Central venous waveforms similar to jugular venous waveforms are obtained by transducing pressure from a central venous catheter with tip in the superior vena cava or right atrium. There is a slight delay in transmission of pressures from the central venous system to the neck veins. (See "Pulmonary artery catheterization: Interpretation of hemodynamic values and waveforms in adults", section on 'Right atrium (RA)'.)

Preliminary reports have suggested potential alternative methods for assessment of jugular venous waveforms including ultrasound, plethysmography, and near-infrared spectroscopy [5-10].

WAVEFORM COMPONENTS — The jugular venous waveform includes three positive waves (ascents), a, c and v, and three negative waves (descents), x, x', and y [5,11] (waveform 1).

●a-wave – This positive wave is caused by transmission of right atrial pressure to the jugular veins during right atrial systole immediately following the P wave on the surface electrocardiogram (ECG).

●x-descent – The x-descent is caused by right atrial relaxation. The x-descent generally coincides with the first heart sound (S1).

●c-wave – The x-descent is usually interrupted by the c-wave at the onset of right ventricular systole, reflecting transmission of pressure from bulging of the closed tricuspid valve into the right atrium, as well as from transmission of adjacent carotid artery pulsation.

The c-wave of the jugular venous pulse commonly cannot be distinguished by clinical examination, although it is usually apparent in the right atrial pressure tracing.

●x'-descent – The x'-descent is caused by continued atrial relaxation and systolic descent of the tricuspid annular plane (the tricuspid valve) during right ventricular systole, causing a decrease in pressure which is the impetus for atrial filling during ventricular systole. The x'-descent coincides with the arterial pulse. The x- and x'-descents are often merged [5].

●v-wave – The v-wave is caused by the rise in right atrial and jugular venous pressure due to continued flow of blood into the right atrium during mid to late ventricular systole while the tricuspid valve is still closed. The peak of the normal v-wave is immediately after ventricular systole, just prior to opening of the tricuspid valve; the v-wave generally coincides with the downslope of the carotid pulse. S2 may be heard during the beginning of the v-wave.

●y-descent – The y-descent is caused by the opening of the tricuspid valve and the rapid flow of blood into the right ventricle from the right atrium and the venous system. The initial y-descent occurs during the rapid filling phase of the right ventricle. The right ventricular third heart sound (S3) corresponds to the nadir of the y-wave. The ascending limb of the y-wave occurs during continued inflow of blood to the right ventricle after the rapid filling phase.

It is often difficult to distinguish a- and v-waves or x- and y-descents during tachycardia. Not infrequently, only one positive and one negative wave are recognized.

ABNORMALITIES OF THE A-WAVE — Elevation in a-waves indicates obstruction to right atrial emptying or increased afterload to atrial contraction. Several arrhythmias are also associated with changes in the a-wave.

Increased a-waves — Abnormally large a-waves occurring with each sinus beat indicate increased resistance (afterload) to right atrial emptying during atrial systole. Increased resistance may occur at the tricuspid valve level or due to decreased right ventricular compliance.

A systematic approach is useful in determining the potential etiology of the large a-wave. A large a-wave in the jugular venous pulse is more likely to occur in the absence of interatrial or interventricular septal defects when atrial contraction can generate higher pressure. Thus, prominent a-waves are uncommon in trilogy and tetralogy of Fallot or in Eisenmenger syndrome.

●Causes of tricuspid valve obstruction include:

•Tricuspid stenosis, including rheumatic tricuspid stenosis and tricuspid atresia. (See "Tricuspid stenosis" and "Clinical manifestations and diagnosis of rheumatic heart disease", section on 'Tricuspid valve disease' and "Tricuspid valve atresia".)

•Right atrial myxoma. (See "Cardiac tumors", section on 'Myxomas'.)

•Carcinoid heart disease. (See "Carcinoid heart disease".)

•Right atrial thrombus.

●Causes of decreased right ventricular compliance include:

•Pulmonary hypertension. (See "Clinical features and diagnosis of pulmonary hypertension of unclear etiology in adults" and "Treatment and prognosis of pulmonary arterial hypertension in adults (group 1)".)

•Pulmonary valve stenosis. (See "Clinical manifestations and diagnosis of pulmonic stenosis in adults".)

•Pulmonary embolism. (See "Epidemiology and pathogenesis of acute pulmonary embolism in adults".)

•Restrictive cardiomyopathy. (See "Restrictive cardiomyopathies".)

•Constrictive pericarditis. (See "Constrictive pericarditis: Diagnostic evaluation".)

•Right ventricular myocardial infarction. (See "Right ventricular myocardial infarction".)

•Right heart failure.

●Other cause – A Bernheim a-wave is the prominent a-wave observed in some patients with left ventricular hypertrophy. It is probably due to atrial interaction, which has been attributed to shared interatrial septum and myocardial fibers [12].

Absent a-waves — With atrial fibrillation, the jugular venous pulse is irregular, the a-wave is absent, and, usually, only v- and y-waves are appreciated. The a-wave may also be absent when the right atrium is dilated and does not possess effective mechanical systole, as with severe Ebstein anomaly or cardiac amyloidosis with a giant silent right atrium. (See "Hemodynamic consequences of atrial fibrillation and cardioversion to sinus rhythm" and "Ebstein anomaly: Clinical manifestations and diagnosis", section on 'Echocardiography' and "Cardiac amyloidosis: Epidemiology, clinical manifestations, and diagnosis", section on 'Echocardiography'.)

Arrhythmias

Impact on a-waves — A number of arrhythmias can be suspected at the bedside by analysis of the character of the venous pulse.

●Absent a-waves – As noted above, a-waves are absent with atrial fibrillation.

●Flutter waves – Flutter waves are occasionally recognized in atrial flutter.

●Cannon a-waves – Prominent a-waves (cannon waves) are caused by arrhythmias in which atrial contraction occurs when the tricuspid valve is closed during ventricular systole. Cannon a-waves can be seen with several rhythm abnormalities.

•Irregular

-Irregular pulse – The most common cause of irregularly occurring cannon waves is atrial, ventricular, or junctional premature beats. In these circumstances, the pulse is also irregular. (See "Supraventricular premature beats" and "Premature ventricular complexes: Clinical presentation and diagnostic evaluation".)

-Regular pulse – Irregular cannon waves associated with a regular, slow pulse suggest complete atrioventricular block; the irregular waves are caused by atrial systole that occurs randomly during ventricular diastole and systole. Complete atrioventricular block is also associated with varying intensity of the first heart sound. (See "Third-degree (complete) atrioventricular block".)

•Regular – Prominent a-waves that are regular often occur during an atrioventricular nodal reentrant or atrioventricular reentrant tachycardia due to simultaneous or almost simultaneous atrial and ventricular activation. (See "Atrioventricular nodal reentrant tachycardia" and "Atrioventricular reentrant tachycardia (AVRT) associated with an accessory pathway".)

Regular cannon waves occur during a junctional rhythm, slow ventricular tachycardia, 2:1 atrioventricular block, and bigeminy. Regular cannon waves may also occur in first-degree atrioventricular block with a markedly prolonged PR interval and atrial systole occurring during the preceding ventricular systole.

Wide complex tachycardia — Analysis of the venous pulse and the intensity of S1 are occasionally helpful in the differential diagnosis of wide complex tachycardia.

●Irregularly occurring cannon a-waves and varying intensity of S1 suggest atrioventricular dissociation and, hence, ventricular tachycardia.

●Absence of cannon a-waves and constant intensity of S1 suggest supraventricular tachycardia with aberrant conduction.

However, it is important to recognize that the diagnosis of dysrhythmia can only be suspected from the abnormalities of the venous pulse; its diagnosis must be confirmed by the ECG. (See "Wide QRS complex tachycardias: Approach to the diagnosis".)

ABNORMALITIES OF THE V-WAVE — A prominent v-wave occurs most commonly in the setting of tricuspid regurgitation and rarely in patients with atrial septal defects. In some patients with an arteriovenous fistula for hemodialysis, a prominent v-wave is seen due to shunting of blood into the venous system [13].

Tricuspid regurgitation — Tall v-waves are most commonly the result of tricuspid valve regurgitation (Lancisi sign) (movie 2). The diagnosis of tricuspid regurgitation can frequently be made by observing the amplitude of the v-wave and the character of the y-descent. (See "Etiology, clinical features, and evaluation of tricuspid regurgitation", section on 'Physical examination'.)

●Mild or moderate tricuspid regurgitation – In patients with mild or moderate tricuspid regurgitation, there may not be any alternation in the jugular venous pulse.

●Severe tricuspid regurgitation produces an early large v-wave (regurgitant wave or c-v-wave), which occurs with the onset of right ventricular systole; the amplitude of the v-wave depends upon the regurgitant volume and right atrial compliance (movie 2). The v-wave is followed by a steep y-descent, the result of the increased pressure gradient across the tricuspid valve, which allows rapid inflow to the right ventricle and decompression of the right atrium in early diastole.

The regurgitant wave of significant tricuspid regurgitation occurs concurrently with the carotid pulse and can be easily recognized by timing the onset with the carotid pulse upstroke. Associated with tricuspid regurgitation is a pansystolic murmur along the lower right and left sternal border that increases in intensity during inspiration, and systolic pulsation of the liver. (See "Auscultation of cardiac murmurs in adults".)

However, severe tricuspid regurgitation may be present without any obvious v-wave in the jugular venous pulse. This is particularly true in patients with a markedly dilated right atrium.

Atrial septal defect — A prominent v-wave is occasionally detected in patients with atrial septal defect without significant pulmonary arterial hypertension and in the absence of tricuspid regurgitation. The mechanism remains unclear. Concomitant systemic venous return and left-to-right shunting during ventricular systole may cause a rapid increase in right atrial pressure and, hence, a prominent v-wave. (See "Clinical manifestations and diagnosis of atrial septal defects in adults".)

ABNORMALITIES OF THE X- AND X'-DESCENTS — A variety of conditions may either enhance or attenuate the x- and x'-descents. The x- and x'-descents are commonly merged, although these may be distinguished in some patients (eg, with prolonged PR interval) [5].

●Prominent x'-descent – A prominent x'-descent occurs when there is vigorous right ventricular contraction. This finding is commonly seen in adults with normal right heart function and pressures and in some patients with atrial septal defect. A prominent x'-descent is also seen in some cases of cardiac tamponade and in some cases of pericardial constriction.

In adults with normal right heart function and pressures, in jugular venous pulsations, the x'-descent is generally more prominent than the y-descent, and the y-descent may not be identified (even though the y-descent is identified in right atrial pressure waveforms). This is because the fall in right atrial volume during right ventricular emptying may not cause an appreciable fall in pressure in the venous system [5]. The y-descent is more likely to be identified in young adults and in pregnant patients, but the x'-remains dominant.

●Decreased x'-descent – The x'-descent is decreased with diminished right ventricular systolic function (eg, right ventricular failure with pulmonary hypertension, post-cardiac surgery right ventricular impairment, or right ventricular infarction) and atrial fibrillation and may be identified with severe mitral regurgitation [5].

The x-descent is also attenuated in patients with severe tricuspid regurgitation [14]. (See "Etiology, clinical features, and evaluation of tricuspid regurgitation", section on 'Clinical manifestations'.)

ABNORMALITIES OF THE Y-DESCENT — Changes in the y-descent can be seen with obstruction to right atrial outflow in which the y-descent is slow or with constrictive pericarditis in which the y-descent is steep.

●Attenuated y-descent

•Slow y-descent – A slow y-descent may suggest tricuspid valve obstruction, which can be confirmed by auscultatory findings of tricuspid stenosis. However, a slow y-descent may also occur in the presence of severe right ventricular hypertrophy, as in pulmonary valve or infundibular stenosis when resistance to early right ventricular filling is increased.

•Elevated JVP with attenuated y-descent – In cardiac tamponade, the mean jugular venous pressure (JVP) is elevated and y-descents are not prominent. An elevated mean JVP with a quiet precordium and the absence of any physical findings of pulmonary arterial hypertension should initiate a search for a hemodynamically significant pericardial effusion.

●Prominent y-descent

•Prominent y-descent – An exaggerated y-descent is seen with prominent v-waves and no restriction to ventricular filling during the rapid filling phase (eg, anxiety, anemia, thyrotoxicosis, pregnancy) [5].

An exaggerated y-descent is also seen with constrictive pericarditis (Friedreich sign), pulmonary hypertension with elevated right ventricular diastolic pressure, right ventricular ischemia/infarction, or cardiomyopathy [5].

The presence of a steep y-descent is strong evidence against significant tricuspid valve obstruction. A rapid y-descent following a large v- (regurgitant) wave is characteristic of tricuspid regurgitation. If the y-descent is prominent or similar in prominence to the x'-descent (x'<y or x' = y), severe cardiac tamponade is excluded [5].

•A sharp y-descent without a prominent v-wave – These findings occur in constrictive pericarditis, restrictive cardiomyopathy, or in severe right-sided heart failure with a markedly elevated systemic venous pressure. (See "Differentiating constrictive pericarditis and restrictive cardiomyopathy" and "Constrictive pericarditis: Clinical features and causes" and "Restrictive cardiomyopathies".)

In constrictive pericarditis and restrictive cardiomyopathy, the mean JVP is elevated, and the amplitudes of the a- and v-waves are usually similar. The most striking movement in the jugular venous pulse is the sharp inward y-descent. In some patients with constrictive pericarditis, a steeper x-descent may be present instead of a sharp y-descent. The mechanism of a sharp x-descent is not clear; it is more likely to occur in effusive-constrictive pericarditis.

However, it is difficult to differentiate between constrictive pericarditis and restrictive cardiomyopathy at the bedside. A left parasternal diastolic impulse and pericardial "knock" favors constrictive pericarditis; physical findings indicating significant right ventricular systolic and pulmonary arterial hypertension are more common in restrictive cardiomyopathy. (See "Differentiating constrictive pericarditis and restrictive cardiomyopathy".)

SUMMARY AND RECOMMENDATIONS

●Clinical role – Examination of jugular venous waveforms is helpful in identifying a variety of cardiovascular disorders including right heart conditions, arrhythmias, and pericardial disease. (See 'Abnormalities of the a-wave' above and 'Abnormalities of the v-wave' above and 'Abnormalities of the x- and x'-descents' above and 'Abnormalities of the y-descent' above.)

●Examination of the jugular veins – Examination of the jugular veins involves observing the veins at varying degrees of head and upper body elevation and with maneuvers (figure 1 and movie 1). (See 'Examination of the jugular veins' above.)

●Distinguishing venous from arterial pulsations – Jugular venous pulsations can be distinguished from carotid artery pulsations by the dominant direction of movement (inward for venous pulsations versus outward for arterial pulsations), palpation (only arterial pulsations are palpable), and effects of inspiration, position, and abdominal pressure on jugular venous pulsations (and absence of effect on arterial pulsations). (See 'Distinguishing venous from arterial pulsations' above.)

●Waveform components – The jugular venous waveform includes three positive waves (ascents), a, c and v, and three negative waves (descents), x, x', and y (waveform 1). A strategy for identifying the waveform components is to initially focus on identifying the descents (x, x', and y) rather than the ascents (a, c, and v). (See 'Waveform components' above.)

●Abnormalities of the a-wave – Elevation in a-waves indicates obstruction to right atrial emptying. Several arrhythmias are also associated with alterations in the a-wave. (See 'Abnormalities of the a-wave' above.)

●Abnormalities of the v-wave – A prominent v-wave occurs most commonly in the setting of tricuspid regurgitation and rarely in patients with atrial septal defects. In some patients with an arteriovenous fistula for hemodialysis, a prominent v-wave is seen due to shunting of blood into the venous system. (See 'Abnormalities of the v-wave' above.)

●Abnormalities of the x- and x'-descents – A prominent x'-descent occurs when there is vigorous right ventricular contraction as seen in adults with normal right heart function and in some patients with atrial septal defect, cardiac tamponade, or constrictive pericarditis. The x'-descent is decreased with diminished right ventricular systolic function, atrial fibrillation, and with severe mitral regurgitation. (See 'Abnormalities of the x- and x'-descents' above.)

●Abnormalities of the y-descent – Changes in the y-descent can be seen with obstruction to right atrial outflow in which the y-descent is slow, or with constrictive pericarditis in which the y-descent is steep. A prominent y-descent excludes severe cardiac tamponade. (See 'Abnormalities of the y-descent' above and "Cardiac tamponade".)