Screening Physical Exam ( Veins: Neck Veins)

To assess central venous pressure and right atrial hemodynamics.

Method Of Exam

Inspect for internal jugular vein pulsations in the neck, in supine position and with neck and trunk raised to approximate angle of 45o. Internal jugular vein pulsation are visible at the root of the neck between clavicular and sternal heads of sternoclidomastoid muscle. Internal jugular vein corresponds to a line drawn from this point to infra auricular region.
Inspection with simultaneous palpation of the carotid and/or auscultation of the heart will assist in identification and timing of the waves.
Inspect the vein from different angles. Apply light tangentially and observe for venous pulsations in the shadow of neck on the pillow.

At 0o jugular veins should be filled. An impulse visible just prior to S1 or the upstroke of the carotid is the "a-wave". This will be followed by a x-descent. The 'c' wave is usually not visible. The 'v' wave occurs after the start of the carotid upstroke and during ventricular systole (which is atrial diastole). When the tricuspid valve opens there is a brisk descent (y-descent).

Observe the venous pressure changes with respiration. There is normally a drop in intrathoracic pressure with inspiration. This decrease is also reflected on the intracardiac pressures. Therefore, an increase in the pressure difference between the SVC/IVC and the RA increases cardiac filling.

Normal:
Neck veins are not visible at 45 o inclination.
Neck veins should be visible in supine position.
JVP should decrease with inspiration.

Abnormal Finding

Neck vein distension at 45 o inclination is abnormal and is indicative of increased central venous pressure. Describe the level to where the pulsations are seen in relationship to the angle of Louis. Note the effect of inspiration. Apply gentle pressure to right upper quadrant and note its effect on neck veins (hepatojugular reflux). If neck vein distension is present identify a, c and v waves and describe their amplitude.

* Distended pulsatile neck veins ( CHF, Tricuspid insufficiency)
* Hepatojugular reflux: Right ventricular non-compliance to increased filling
* Distended non- pulsatile neck veins: ( SVC syndrome , cardiac tamponade, Constrictive pericarditis). These patients usually have prominent descents.
* Quick Y descent and X descent: (Constrictive pericarditis)
* Distended veins during expiration only: (COPD, Asthma)
* Prominent "a" wave: "a" waves are due to atrial contraction and when abnormally prominent indicate atrial contraction into a noncompliant right ventricle or through a stenotic or closed tricuspid valve. In complete heart block and with premature ventricular contraction there is loss of a-v synchrony. When the atrial and ventricular contractions coincide a prominent wave is seen. This is called cannon a-wave. A noncompliant right ventricle can be hypertrophied (secondary to pulmonary hypertension) or "stiff" due to scar (ischemia/infarct) or infiltrative disease (amyloid).
* JVP which increase with inspiration indicate restricted filling of the right sided chambers (Kussmaul's signs).
* Absent "a" waves: (Atrial fibrillation).
* "v" waves are most commonly due to an insufficient tricuspid valve with the ventricular systolic pressure reflected in the atrium during atrial filling (diastole).
* Prominent "v" wave: (Tricuspid regurgitation).
* Cannon wave: (Heart block, Premature ventricular contraction).


Knowledge Base

* Anatomy of neck veins
o Internal jugular vein
+ Deep behind sternoclidomastoid muscle
+ From the angle between sternal and clavicular head of sternomastoid to angle of neck
o External jugular vein
* Clinical methods for estimation of central venous pressure.
* Physiology of a, c, v waves.
o a: atrial contracion
o v: venous filling
o x descent: atrial relaxation
o y descent venous emtying
o c: not easily visible
* Effect of respiration and pleural negative pressure on atrial filling.
o Increased intrathoracic negative pressure facilitates venous return and filling of atrium
o Hence neck veins decrease in height during inspiration
* Conditions causing venous distension and prominent a or c or v waves.
* Anatomical relationship to neck muscles and carotid artery.
* Hepatojugular reflux.