JVP's - Appearance and Interpretation

Introduction

The JVP (jugular venous pressure) is a manometer of pressure in the right atrium; when pressure in the atrium is high the JVP will be raised and when right atrial pressure is low the JVP will drop.

Features of the JVP

A venous pulse is not usually palpable.

Pressing at the base of the vein will make the vein visible as it continues to fill and distend above the point of pressure NB do not do this in exams.

Hepatojugular reflex aids identfication of JVP - probably by forcing blood out of liver into IVC and therefore into right atrium increasing its pressure.

JVP alters with changes in posture.

How to find the JVP

Sit patient at 45° and turn head slightly away from you.

Look for JVP in internal jugular vein (not external jugular vein) medial to the clavicular head of sternocleidomastoid; the vein passes behind the angle of the jaw in direction of earlobe.

Measure JVP in cm above the sternal notch - a vertical not diagonal distance - if larger than 3cm the JVP is raised.

The JVP Waveform

Graph of height of JVP with time

Abnormalities of the JVP

1) Raised JVP with normal waveform

2) Raised JVP with absent pulsation

3) Large a wave

4) Extra-large a wave = Cannon wave

Occurs when atrium contracts against closed tricuspid eg

ie any condition in which the atria and the ventricles are not conducting in appropriate rhythm

5) Absent a wave

6) Systolic waves = combined c-v waves = big v waves

7) The slow y descent occurs in tricuspid stenosis (if the HR is so low as to allow the length of descent to be appreciated!)

8) Paradoxical JVP = Kussmaul's sign

Normally the JVP should rise on expiration and fall on inspiration.

When the JVP rises on inspiration it indicates