Tamponade physiology on invasive hemodynamics is most accurately suggested by which finding?

• A. Elevated systolic pressures with normal diastolic pressures
• B. Diastolic pressure equalization across chambers with elevated filling pressures and impaired ventricular filling
• C. Decreased right atrial pressure
• D. Increased left atrial pressure without other changes

Answer: (B)

Tamponade physiology is defined by external pericardial pressure compressing the heart so that during diastole the ventricles fill under the same restrictive pressure. On invasive measurements this shows up as diastolic pressures that become roughly equal across the heart chambers (right atrium, right ventricle, left ventricle) and the measured filling pressures (such as the pulmonary capillary wedge pressure) are elevated. The external constraint reduces overall filling, so the ventricles can’t expand normally, which drops stroke volume and cardiac output even though the filling pressures are high.

This pattern fits best because it reflects the uniform diastolic constraint of all chambers by the edematous pericardial space, unlike scenarios where pressures rise or fall in only one chamber or where diastolic pressures don’t equilibrate.