Clinical meaning
Cardiac tamponade occurs when pericardial fluid accumulates faster than the pericardium can stretch, raising intrapericardial pressure above right atrial and then right ventricular diastolic pressure. This external compression collapses the right-sided chambers during diastole, severely reducing ventricular filling and cardiac output.
Diagnosis & workup
Diagnostics & workup: - Order bedside echocardiogram (first-line diagnostic) - Identify right atrial and ventricular diastolic collapse on echo - Order ECG (electrical alternans, low voltage) - Assess for pulsus paradoxus >10 mmHg - Order chest X-ray (enlarged cardiac silhouette if chronic) - Order CT if etiology unclear
Risk factors: - Pericarditis (viral, uremic, malignant) - Chest trauma (penetrating or blunt) - Post-cardiac surgery or catheterization - Aortic dissection into pericardium - Malignancy with pericardial metastasis - Anticoagulant therapy