Which of the following outcomes would indicate successful pericardiocentesis?

• A. Decrease in right heart pressure with pericardial pressure of zero; increase in blood pressure and cardiac output
• B. Worsening hypotension
• C. No change in hemodynamics
• D. Increase in right atrial pressure

Answer: (A)

Relief of tamponade improves the heart’s filling and output. When the pericardial pressure is high, the heart cannot fill properly, so venous return is limited and cardiac output falls, causing low blood pressure. After successful pericardiocentesis, the pericardial pressure drops toward zero, removing external compression. With the heart no longer squeezed, right- and left-sided diastolic filling improves, right heart pressures fall, and systemic pressures and cardiac output rise. That combination—lower right heart pressures with the pericardial space effectively decompressed (near zero pressure) and an increase in blood pressure and cardiac output—matches a successful drainage.

If the patient remains hypotensive, there’s persistent tamponade or another issue; if there’s no hemodynamic change, the drainage may be insufficient; if the right atrial pressure were to rise, that would suggest ongoing compromise or worsening limitation of filling, not successful relief.