The jugular venous pressure revisited
ABSTRACTAssessment of the jugular venous pressure is often inadequately performed and undervalued. Here, we review the physiologic and anatomic basis for the jugular venous pressure, including the discrepancy between right atrial and central venous pressures. We also describe the correct method of evaluating this clinical finding and review the clinical relevance of the jugular venous pressure, especially its value in assessing the severity and response to treatment of congestive heart failure. Waveforms reflective of specific conditions are also discussed.
KEY POINTS
- If the jugular venous pressure differs from the true right atrial pressure, the jugular venous pressure is always the lower value.
- The jugular venous pressure is useful to observe when diagnosing congestive heart failure and when considering the need for or the adequacy of diuresis.
- The jugular venous wave form is more difficult to observe than its elevation but can yield useful information in the assessment of certain arrhythmias, right-heart conditions, and pericardial disease.
SIGNIFICANCE OF JUGULAR VENOUS PRESSURE ELEVATION
Elevated jugular venous pressure is a manifestation of abnormal right heart dynamics, mostly commonly reflecting elevated pulmonary capillary wedge pressure from left heart failure.12 This usually implies fluid overload, indicating the need for diuresis.
Exceptions to this therapeutic implication include the presence of a primary right heart condition, pericardial disease, certain arrhythmias, and conditions that elevate intrathoracic pressure. These will be discussed below. One important example is the acute jugular venous pressure elevation seen in right ventricular infarction, in which the high venous pressure is compensatory and its reduction can produce hypotension and shock.13
Primary right heart conditions also include right-sided valvular disease, cor pulmonale (including pulmonary embolism and pulmonary hypertension), and the compressive effect of pericardial tamponade or constriction. A normal or near-normal jugular venous pressure significantly decreases the likelihood of significant constriction or of tamponade of a degree necessitating urgent pericardiocentesis.14
SPECIAL CIRCUMSTANCES
Presence of an intravenous line in the neck
An intravenous line in the neck will often prevent observation of the jugular venous pressure. A simple measure can often compensate for this. If the venous line can be temporarily disconnected, the central venous pressure can be measured directly. Using sterile technique, the line can be flushed with saline and aspirated to bring blood into the transparent tubing. Leaving the proximal end open to the air, and alternately raising and lowering it to confirm free flow, the level to which the blood rises can be easily observed. Observing small cardiac and respiratory variations of the meniscus confirms free communication with the central veins. Attaching the line to a transducer is another option, but this may be time-consuming, and establishing an accurate zero point is often difficult.
The previously described discrepancy between jugular venous pressure and central venous pressure has to be considered when drawing conclusions from this measurement.
Intrathoracic pressure elevators
Positive pressure ventilation will elevate intrathoracic pressure (including right atrial pressure) and hence the jugular venous pressure, making interpretation difficult.15 Large pleural effusions or pneumothorax may have a similar effect.16
Superior vena cava syndrome
Markedly elevated jugular venous pressure is here associated with absent or very diminished pulsation, as the caval obstruction has eliminated free communication with the right atrium.17 Associated facial plethora and edema, papilledema, and superficial venous distention over the chest wall will often confirm this diagnosis.
THE WAVEFORM
While the main purpose of viewing the neck veins is to establish the mean pressure, useful information can often be obtained by assessing the waveform. Abnormalities reflect arrhythmias, right heart hemodynamics, or pericardial disease.18 Changes may be subtle and difficult to detect, but some patterns can be quite readily appreciated (Figure 2). A limited selection follows.
Arrhythmias
Cannon a waves. These intermittent sharp positive deflections in the venous pulse represent right atrial contraction against a closed tricuspid valve. They are most commonly associated with premature ventricular complexes, but they occur in other conditions in which atrial and ventricular beating are dissociated, including complete heart block, atrioventricular dissociation, and electronic ventricular pacing.19–21
Repetitive cannon waves. These may be seen with atrioventricular junctional tachycardia or ventricular tachycardia with 1:1 retrograde ventriculoatrial conduction in which the tricuspid valve is closed to every atrial beat.
Fine rapid regular pulsation may be seen in atrial flutter and may be a useful clue in distinguishing this from sinus rhythm when there is 4:1 atrioventricular conduction and a normal ventricular rate.
Abnormal right heart hemodynamics
Large v waves (Lancisi sign). These surges, replacing the usual x descent in systole, are seen in tricuspid insufficiency when the right atrium and its venous attachments are not protected from the right ventricular systolic pressure.22 High right ventricular pressure will obviously enhance this systolic surge.
Large a waves. These reflect resistance to right atrial outflow and may be seen when right ventricular compliance is reduced by hypertrophy from chronic pressure overload or in tricuspid stenosis.23
Pericardial disease
Kussmaul sign is the paradoxical increase in jugular venous pressure with inspiration, observed in conditions associated with limited filling of the right ventricle. It is typically associated with constrictive pericarditis, although it occurs in only a minority of people with this condition.24 It may also be seen in restrictive cardiomyopathy, massive pulmonary embolism, right ventricular infarction, and tricuspid stenosis.25
Diaphragmatic descent during inspiration increases intra-abdominal pressure and decreases intrathoracic pressure. The resulting increased gradient between the abdomen and thorax enhances venous return from splanchnic vessels, which in the setting of a noncompliant right ventricle may result in increased right atrial (and, hence, jugular venous) pressure.26
It is important to point out that the Kussmaul sign does not occur with cardiac tamponade in the absence of associated pericardial constriction.
Exaggerated y descent is typically seen in pericardial constriction, in which the high pressure of the v wave falls rapidly at the onset of diastole, given initial minimal right ventricular resistance. Flow is abruptly stopped when the intrapericardial space is filled.
