A 40-year-old woman with tuberculous pericardial effusion has blood pressure of 90/70 mmHg, jugular venous distension with preserved x descent, and muffled heart sounds. The radial pulse falls by more than 12 mmHg during inspiration. Which additional finding on right heart catheterization would confirm the suspected diagnosis?

• A A step-up in oxygen saturation at the right ventricular level
• B Equalization of diastolic pressures in all four cardiac chambers ✓
• C Diastolic pressure gradient between right atrium and right ventricle
• D Systolic pressure gradient across the left ventricular outflow tract

Explanation

The vignette describes Beck triad with pulsus paradoxus, indicating cardiac tamponade. In tamponade, the compressive effusion equalizes diastolic pressures across all four chambers, typically within 5 mmHg. An oxygen saturation step-up at the right ventricle indicates a left-to-right shunt such as VSD, not tamponade, which kills the most tempting distractor for students who conflate constrictive pericarditis shunt physiology with chamber equalization.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.