CARDIAC TAMPONADE

Life-threatening condition resulting from accumulation of pericardial fluid under pressure; impaired filling of cardiac chambers and decreased cardiac output.

Etiology 

Previous pericarditis (most commonly metastatic tumor, uremia, viral or idiopathic pericarditis), cardiac trauma, or myocardial perforation during catheter or pacemaker placement.



History 

Hypotension may develop suddenly; subacute symptoms include dyspnea, weakness, confusion.

Physical Examination 

Tachycardia, hypotension, pulsus paradoxus (inspiratory fall in systolic blood pressure >10 mmHg), jugular venous distention with preserved x descent but loss of y descent; heart sounds distant. If tamponade develops subacutely, peripheral edema, hepatomegaly, and ascites may be present.

Laboratory ECG 

Low limb lead voltage; large effusions may cause electrical alternans (alternating size of QRS complex due to swinging of heart).

CXR 

Enlarged cardiac silhouette if large (>250 mL) effusion present.

Echocardiogram 

Swinging motion of heart within large effusion; prominent respiratory alteration of RV dimension with RA and RV collapse during diastole. Doppler shows marked respiratory variation of transvalvular flow velocities.

Cardiac Catheterization 

Confirms diagnosis; shows equalization of diastolic pressures in all four chambers; pericardial = RA pressure.

Cardiac Tamponade TREATMENT

Immediate pericardiocentesis and IV volume expansion.