Cardiac tamponade occurs when fluid, such as blood, pus, or effusion, accumulates in the pericardial sac surrounding the heart rapidly enough or in sufficient quantity to compress the heart chambers and impair their ability to fill with blood. This is a medical emergency because the compressed heart cannot pump enough blood to sustain the body’s organs. On echocardiography, tamponade shows a pericardial effusion along with specific signs of hemodynamic compromise, including collapse of the right atrium and right ventricle during specific phases of the cardiac cycle, and exaggerated respiratory variation in Doppler flow velocities. Emergency echocardiography is often the first step in diagnosing tamponade and can guide pericardiocentesis, the needle procedure used to drain the fluid.
Sonography Term