The Stanford 25

An Initiative to Revive the Culture of Bedside Medicine

Neck Veins & Wave Forms 

In addition to attending as a cardiologist, Dr. Ronald Witteles is Senior Associate Program Director for the Internal Medicine Residency program. He conducts research into heart failure and serves as Associate Director of the CCU and Co-Director, Stanford Amyloid Center. In the video below he demonstrates his technique for evaluating neck veins and measuring JVP. (Video to come.)

Introduction: Blood flow through neck veins reflects the action of the right atrium.

There are two main objectives here:

  1. Determine the jugular venous pressure.
  2. Examine the wave forms for abnormalities.

Technique:

[Stanford 25 Video forthcoming, see below.]

Note: The Department of Medicine had acquired a “Harvey” cardiac patient simulator capable of simulating the neck vein wave forms (as well as heart sounds and peripheral pulses) of many important CV conditions. See our blog post for more detail.

Wave Forms

Normal Wave form:

Normal JV wave. Click for image credit via Wikimedia Commons.

There are essentially two positive waves ‘a’ and ‘v’, one occurring just before the first heart sound or the carotid impulse, and one just after. When the heart rate is 80 or less, they are fairly easy to time, but if the heart rate is fast, then you may need to auscultate while you observe.

A few pearls from RON WITTELES MD:

  • Get the patient to relax, raise the bed so you are not straining.
  • Take the pillow away; the waveforms are often better seen with the head lying directly against the examining table/bed.
  • Position the neck until you have the best view.
  • Make sure the room is well lit, but there is no need for shining a flashlight, penlight or other direct light.
  • Make your first goal just to see a pulsation, and then decide if it is arterial or venous by applying the following criteria to identify venous waves:
    • Venous wave is bifid, flicking like a snake’s tongue.
    • It rises when you lower the head of the bed and sinks when you raise the head of the bed.
    • It changes with respiration, sinking into the chest with inspiration.
    • It is not palpable.
    • It is fine to use the external jugular vein, as long as you can see clear wave forms in it.
  • Commonly, a prominent pulsation is mistaken for that of the carotid artery rather than of the JVP. To differentiate, press on the RUQ while watching the neck. The JVP should rise in all individuals with this maneuver; whereas a carotid pulsation should not change.
  • The JVP can be assessed on either the right or left. On occasion (musculoskeletal anatomy, venous clots) the pulsations can only be visualized on one side. If you cannot clearly define the JVP on the right internal jugular, examine the left.
  • If you cannot determine the JVP, report the exam as “JVP not visualized” rather than “no JVD” (which implies that the JVP was visualized and is not elevated).

Once you have determined that you are seeing the venous waves then measure the Jugular Venous Pressure:

  • Identify JVP at the highest point of pulsation.
  • Extend card or ruler horizontally from highest pulsation point , cross with ruler placed on Angle of Louis (let’s say it was 8cm).
  • Add 5 cm (to get to the center of the atrium) and then report the JVP as “the jugular venous pressure was 13 cm of water” (not mercury).

Things to know about the venous waves:

  • A wave: atrial contraction (ABSENT in atrial fibrillation).
  • C wave: ventricular contraction (tricuspid bulges). YOU WON’T SEE THIS.
  • X descent: atrial diastole.
    • Usually more prominent.
  • V wave: atrial venous filling.
  • Y descent: ventricular filling (tricuspid opens).

Some findings you should see:

  • Elevated A Wave: resistance to right atrial emptying, may occur at or beyond the tricuspid valve.
  • A CANNON ‘a’ wave is a dramatic site and frequent if you look for it. It occurs when an atrium contracts against a closed tricuspid valve.
    • Seen in AV dissociation.
  • Absent A Wave: No atrial contraction, common to atrial fibrillaiton.
    • Elevated V Wave or ARTERIALIZATION of the ‘v’ wave happens with TRICUSPID REGURGITATION:
      • The ventricle contracts and if the tricuspid valve does not close well, a jet of blood shoots into the right atrium.
      • Tricuspid regurgitation if significant will be accompanied by a pulsatile liver (feel over the lower costal margin).
      • You will also hear the murmur of TRICUSPID REGURGITATION–a panysystolic murmur that increases on inspiration.
        • Tricuspid regurgitation most common cause.

        Other signs:

      • Kussmaul’s sign: neck veins rise in inspiration rather than fall–often a sign of perciardial tamponade.
      • Friedrich’s sign: exaggerated x wave or diastolic collapse of the neck veins from constrictive pericarditis.

Further Reading:

Lipton B. Estimation of central venous pressure by ultrasound of the internal jugular vein. Am J Emerg Med. 2000 Jul;18(4)

  • Excerpt from abstract: “Lipton Although bedside visual inspection of the height of the jugular veins as an estimate of CVP has been an integral part of the physical examination, its major limitation has been that the jugular veins are not always observable. In obese patients, a layer of fat often obscures the jugular pulsations. [Ultrasound] has proven to be a powerful tool to noninvasively visualize neck veins in the emergency department.”

Embedded Videos & Links (not produced by Stanford, click through for credit and source).

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Written by stanford25admin

June 7, 2010 at 3:29 pm

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