How is the diagnosis of cardiac tamponade confirmed?

• A. ECG
• B. Echocardiogram or chest X-ray
• C. CT scan
• D. MRI

Answer: (B)

A key concept is that confirming cardiac tamponade hinges on imaging that shows the fluid and its effect on heart filling, with echocardiography providing the definitive confirmation. An echocardiogram directly visualizes a pericardial effusion and reveals the hemodynamic impact, such as diastolic collapse of the right atrium or right ventricle and variation in filling with respiration. It also helps gauge the need for urgent intervention, like pericardiocentesis. Chest X-ray can sometimes show an enlarged silhouette if the effusion is large, but it is not diagnostic on its own and can be normal in tamponade. CT or MRI offer detailed anatomy but are not the rapid confirmation you rely on in an acute setting. An ECG might show electrical changes like electrical alternans, but those findings are not confirmatory. Therefore, echocardiography is the best answer, with chest X-ray as a supportive, non-definitive adjunct.