Interpretation of the jugular venous pressure waveform

What it is

The jugular venous pulse is read as a waveform, not as one number. Each part of the wave belongs to one point in the heart cycle, and naming that point is what turns a raised neck vein into a diagnosis.

The a wave is atrial contraction, and it comes before the carotid pulse. The v wave is atrial filling, and it comes with the carotid pulse; it rises in the right atrium just before the opening of the tricuspid valve. The y descent follows, as the atrium empties once the tricuspid valve opens. A jugular venous pulse tracing can therefore show prominent x and y descents, or lose a descent.

How it presents

The named waves and what each one points to:

• Prominent a wave: TS, PS, pulmonary HTN, RVH.
• Canon a wave: complete heart block, ventricular tachycardia.
• Absent a wave: atrial fibrillation.
• Prominent v wave: TR. A prominent CV wave is seen in tricuspid regurgitation.
• Absent y descent: a malignant pericardial effusion shows this on the waveform.
• Sharp and deep y descent: this is Friedreich's sign in constrictive pericarditis. It comes from rapid early diastolic filling of the right ventricle which then suddenly halts because of a non-compliant pericardium.
• Prominent x and y descents together: constrictive pericarditis again, alongside a pericardial knock and pulsus paradoxus.

Raised jugular venous pressure is itself one of the right-sided findings in heart failure, next to peripheral pitting edema and hepatosplenomegaly, and it belongs with the symptoms of fluid retention rather than with the pulmonary symptoms of left-sided failure.