JVP

Question 1

What is JVP?

Answer 1

This is the jugular venous pressure which acts as a capricious manometer of right atrial pressure.

Question 2

How do you assess JVP?

Answer 2

Observe patient at 45 degrees with their hand slightly to the left and neck relaxed.
The JVP is assessed by measuring the vertical height from the manubriosternal angle to the top of the pulse- 4cm above the sternal angle at 45 degrees is elevated.

Question 3

How do you assess if the pulse is venous?

Answer 3

The JVP is usually impalpable and obliterated by finger pressure on the vessel.
Rises transiently with pressure on the abdomen or on the liver and alters with posture and respiration.
Usually has a double pulse for every arterial pulse.

Question 4

What are the waveforms of JVP?

Answer 4

Waves
a – pre-systolic: produced by right atrial contraction
c - bulging of the tricuspid valve into the right atrium during ventricular systole (isovolumic phase)
v – occurs in late systole; increased blood in the right atrium from venous return
The a and v waves can be identified by timing the double waveform with the opposite carotid pulse. The a-wave will occur just before the pulse and the v wave occurs towards the end of the pulse.
Descents
x – a combination of atrial relaxation, downward movement of the tricuspid valve and ventricular systole
y – the tricuspid valve opens and blood flows into the right ventricle

Question 5

Causes of raised JVP

Answer 5

Heart failure (normal waveform).
Constrictive pericarditis (JVP increases on inspiration - called Kussmaul’s sign).
Cardiac tamponade.
Fluid overload - eg, renal disease (normal waveform).
Superior vena cava obstruction (absent pulsation but fixed raised JVP).

Question 6

Abnormalities of a wave

Answer 6

• It disappears in atrial fibrillation.
• Large A waves occur in any cause of right ventricular hypertrophy (pulmonary hypertension and pulmonary stenosis) and tricuspid stenosis.
• Extra-large A waves (called cannon waves) occur in complete heart block and ventricular tachycardia- cannon waves occur when the right atrium contracts against a closed tricuspid valve

Question 7

Abnormalities of V wave

Answer 7

Tricuspid regurgitation - called cv or v waves and occurring at the same time as systole (a combination of v wave and loss of x descent); there may be earlobe movement.

Question 8

What can cause slow y descent?

Answer 8

Tricuspid stenosis.

Right atrial myxoma.

Question 9

What can cause steep y descent?

Answer 9

Right ventricular failure.
Constrictive pericarditis.
Tricuspid regurgitation.
(The last two conditions have a rapid rise and fall of the JVP - called Friedreich’s sign.)