Pericardial tamponade
Formal Definition
A life-threatening accumulation of fluid (blood, pus, effusion, or air) in the pericardial space causing compression of the cardiac chambers, impaired diastolic filling, reduced cardiac output, and ultimately obstructive shock; classic clinical triad of Beck includes hypotension, muffled heart sounds, and jugular venous distension; pulsus paradoxus (>10 mm Hg drop in systolic BP with inspiration) is a sensitive finding; echocardiography is diagnostic, with emergent pericardiocentesis as definitive therapy.
How It's Used on the Ward
"Tamponade" or "pericardial tamponade" — fluid or blood in the sac around the heart is squeezing it so it can't fill properly between beats, dropping cardiac output; the telltale signs are low blood pressure, muffled heart sounds, and bulging neck veins (Beck's triad); echo confirms and pericardiocentesis is the immediate fix.
Example
""52-year-old woman with breast cancer on chemotherapy, presents with 2 days of progressive dyspnea, chest pressure, lightheadedness. Tachycardic to 134, BP 88/64 with pulsus paradoxus of 18 mmHg, JVP to angle of jaw, muffled heart sounds. Bedside echo: large circumferential pericardial effusion (>2cm) with right atrial systolic collapse and respiratory variation in mitral inflow. Diagnosis: malignant pericardial effusion causing cardiac tamponade. Emergent pericardiocentesis at bedside under echo guidance — 600 mL of serosanguinous fluid drained, hemodynamics improved immediately. Drain left in place, oncology consult for management.""
Clinical Context
Etiology: malignant pericardial effusion (breast, lung, lymphoma most common), uremic pericarditis (ESRD), post-MI free wall rupture (usually days 3-7 post-MI), traumatic (penetrating chest trauma, iatrogenic post-cardiac cath/cath lab procedures), aortic dissection with rupture into pericardium, infectious (TB, viral pericarditis, bacterial from endocarditis), autoimmune (lupus, RA), idiopathic. Echo findings: pericardial effusion (size, location), right atrial systolic collapse (early sign), right ventricular diastolic collapse (more specific), respiratory variation in mitral/tricuspid inflow (>25% mitral, >40% tricuspid), IVC plethoric (loss of inspiratory collapse). Pulsus paradoxus: >10 mm Hg drop in systolic BP with inspiration (not truly paradoxical — exaggeration of normal physiology). Beck's triad (hypotension, muffled heart sounds, JVD) — present in only ~30% of cases. Treatment: emergent pericardiocentesis (subxiphoid approach, echo-guided preferred), pericardial window for recurrent malignant effusions, treat underlying cause. In trauma: emergent OR for surgical repair (pericardiocentesis is temporizing only).