Cardiac tamponade is best defined as what?

• A. Compression on the heart from a build-up of fluid in the pericardial sac
• B. Blockage of a coronary artery
• C. Enlargement of the left ventricle
• D. Inflammation of the pericardium without effusion

Answer: (A)

The main idea is that tamponade is heart compression caused by fluid accumulating in the pericardial sac, which restricts the heart’s ability to fill during diastole. This increased intrapericardial pressure prevents ventricles from expanding to normal volumes, so stroke volume and cardiac output drop, leading to symptoms of hemodynamic compromise. The situation is characterized by the physical effect of the fluid on the heart, not by a blockage of blood flow, enlargement of the ventricle, or inflammation without fluid.

So the correct concept is that tamponade results from a build-up of fluid in the pericardial space compressing the heart. By contrast, a coronary artery blockage causes ischemia or infarction, enlargement of the left ventricle is a structural enlargement, and pericarditis without effusion is inflammation without an effusion.