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CVP Waveform Interpretation — FRCA Final MCQ

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ModerateIntensive Care MedicineCVP Waveform InterpretationFRCA Final

A correctly positioned and zeroed central venous pressure transducer displays no discernible a waves. The intervals between successive waveform complexes vary unpredictably from beat to beat. Which cardiac rhythm is most likely?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: CAtrial fibrillation

The correct answer is C, atrial fibrillation. The CVP a wave is generated by coordinated right atrial contraction; fibrillating atria do not produce an organised contraction, so discrete a waves disappear. Variable atrioventricular conduction produces an irregularly irregular ventricular rhythm and therefore irregular spacing of the remaining CVP complexes. Sinus rhythm normally produces one a wave before each c wave. Complete heart block causes atrioventricular dissociation and intermittent cannon a waves when the atrium contracts against a closed tricuspid valve. Atrial flutter retains organised, usually regular rapid atrial activity, although individual atrial pressure waves may be difficult to resolve. Junctional rhythm is generally regular and may produce absent, retrograde or cannon a waves depending on atrioventricular timing.

Reference: Biuzzi C, et al. Central Venous Pressure Revisited: Physiology, Pitfalls, Misconceptions, and Modern Clinical Interpretation in Critical Care. CVP waveform interpretation. Journal of Clinical Medicine. 2026;15:4227. https://pubmed.ncbi.nlm.nih.gov/42279088/