PCL 1 (Jugular Venous Pulse)

Definition

• Also known as jugular venous pressure
• Defined as pulse/pressure observed indirectly over the venous system
• Can be used to differentiate different forms of heart and lung disease

• Usually assessed by observing RHS of patient's neck
• Normal mean pressure (vertical distance above midpoint of right atrium): 6 - 8 cm H2O
• Deviations: hypovolemia (<5)>9)
• Normal jugular venous pulse: 3 positive waves

Waveforms

• Biphasic
• 'a' wave: atrial contraction
• Peak of 'a' wave demarcates end of atrial systole
• 'c' wave: ventricle contraction, causing AV valves to bulge towards atria
• 'v' wave: tricuspid valve closed, caused by pressure increase in atrium as venous return fills atria
• 'x' descent: follows 'a' wave
• Represents atrial relaxation and rapid filling due to low pressure
• 'x (x prime): follows 'c' wave
• Represents right ventricle pulling tricuspid valve downward during ventricular systole
• Can measure right ventricle contractility
• 'y' descent: rapid emptying of atrium into ventricle following opening of tricuspid valve

Clinical Significance
Abnormalities of 'a' waves

• Disappears in atrial fibrillation
• Large waves: right ventricular hypertrophy or tricuspid stenosis
• Extra large (cannon 'a') waves: complete heart block or ventricular tachycardia

Prominent 'v' waves

• Tricuspid regurgitation - called "CV" waves
• Occur at same time as systole
• May be ear lobe movement

Slow 'y' descent

• Tricuspid stenosis
• Right atrial myxoma

Steep 'y' descent

• Right ventricular failure
• Constrictive pericarditis
• Tricuspid regurgitation
• Last 2 conditions have Fredreich's Sign - rapid rise and fall of JVP

Extras
http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=cm&part=A622 (more detailed)
http://www.patient.co.uk/doctor/Jugular-Venous-Pressure.htm