How to measure pulsus paradoxus

Discover the key to confidently diagnosing cardiac tamponade with this quick guide on measuring pulsus paradoxus.

Lorrel E.B. Toft, MD
Lorrel E.B. Toft, MD
22nd Feb 2024 • 2m read

When faced with a patient possibly suffering from cardiac tamponade, obtaining a pulsus paradoxus measurement can be a game-changer. It's a vital tool in confirming the diagnosis, and distinguishing tamponade from pericardial effusion or other conditions like asthma or COPD exacerbations.

Preferred method

Here’s a step-by-step guide to measuring pulsus paradoxus:

  1. Take an automated BP measurement: start with the automated measurement to gauge the patient’s baseline systolic blood pressure.
  2. Prepare for manual BP measurement: equip yourself with a manual sphygmomanometer.
  3. Inflate the cuff: inflate approximately 20 mmHg higher than the automated systolic measurement.
  4. Release the pressure slowly: listen for the first Korotkoff sound and note the pressure.
  5. Continue release: record when Korotkoff sounds occur with every heartbeat.
  6. Calculate the pulsus paradoxus: subtract the expiratory systolic pressure from the inspiratory systolic pressure.

Understanding the numbers

The difference in pressures reflects the dynamics of inspiration and expiration. During expiration, higher pressure allows blood flow into the artery, producing the Korotkoff sound. Conversely, during inspiration, lower arterial pressure halts blood flow, resulting in silence.

Diagnosing cardiac tamponade

Mastering the art of measuring pulsus paradoxus empowers clinicians in swiftly diagnosing cardiac tamponade, saving critical time in emergencies. Stay tuned for more insights into tamponade diagnosis with electrocardiogram and echocardiogram findings. Unlock the secrets of cardiac emergencies with our comprehensive course.

Start the first chapter of our Cardiac Tamponade course for free