AKT · Cardiovascular/Pericardium

Pericardial effusion & cardiac tamponade

Fluid accumulation in the pericardial sac → impaired cardiac filling when rapid/large

Overview

Accumulation of fluid (or blood) in the pericardial sac. A slow effusion may be tolerated, but rapid or large accumulation raises intrapericardial pressure and prevents ventricular filling — cardiac tamponade, an obstructive shock. Beck's triad (hypotension, raised JVP, muffled heart sounds) with pulsus paradoxus is the clinical signature; treatment is pericardiocentesis.

Recognise

Effusion: dyspnoea, chest discomfort, muffled heart sounds; may be asymptomatic if slow
Tamponade — Beck's triad: hypotension, raised JVP, muffled heart sounds; pulsus paradoxus (>10 mmHg inspiratory drop in systolic BP); tachycardia
Causes: pericarditis, malignancy, uraemia, trauma/haemopericardium (post-procedure, type A dissection), TB

Red flags

Cardiac tamponade (shock + raised JVP + muffled sounds, pulsus paradoxus) → emergency echo-guided pericardiocentesis
Haemopericardium from type A aortic dissection or trauma → surgical management, not just drainage

Differentials & how to tell them apart

Tension pneumothoraxabsent breath sounds, tracheal deviation, hyper-resonance — also obstructive shock

Pulmonary embolismhypoxia, RV strain; raised JVP without effusion

Constrictive pericarditischronic, calcified pericardium, Kussmaul's sign rather than acute collapse

Investigations

Urgent echo (effusion size, diastolic chamber collapse, IVC plethora — the diagnostic test); ECG (low voltage, electrical alternans); CXR (globular/'water-bottle' heart); identify cause (U&Es, malignancy, dissection imaging).

Management

Tamponade → urgent echo-guided pericardiocentesis

1Suspect tamponade from Beck's triad + pulsus paradoxus; confirm with urgent echo (diastolic chamber collapse).Gate: Tamponade physiology → emergency pericardiocentesis (or surgical drainage); IV fluids only temporise. Haemopericardium from aortic dissection/trauma → surgery, not needle drainage alone.
2Send pericardial fluid for analysis, treat the underlying cause, and consider a pericardial window for recurrent (e.g. malignant) effusions.

Echo-guided pericardiocentesis (or surgical drainage) — definitive treatment of tamponade; send fluid for cytology/microbiology

IV fluids as a temporising measure — supports filling while preparing to drain — do not delay drainage

Treat the cause — dialysis (uraemic), chemo/window (malignant), surgery (dissection/trauma)

Key points

Hypotension + raised JVP + muffled heart sounds (Beck's triad) with pulsus paradoxus and electrical alternans = cardiac tamponade → urgent echo then pericardiocentesis. A type-A-dissection haemopericardium needs surgery, not just a needle.

Monitor & prognosis

Haemodynamics, repeat echo for re-accumulation, drain output.

Tamponade is rapidly fatal untreated but reversible with prompt drainage.

Source: ESC; cross-ref acute_care