Clinical exam · Cardiovascular system
Cardiac tamponade: Beck triad and pulsus paradoxus !
- Syndrome
Fluid or blood under pressure in the sac around the heart stops it from filling; it is an emergency recognized at the bedside.
Updated 2026-11-01
See it in 3D: Pericardium · Right atrium · Right ventricle · Internal jugular vein
What it is
Tamponade occurs when pressure inside the pericardium exceeds right heart filling pressure. Output falls and obstructive shock follows. Beck triad and pulsus paradoxus are the classic signs; echocardiography confirms.
Key findings
- Beck triad: hypotension, jugular venous distension and muffled heart sounds.
- Pulsus paradoxus: inspiratory systolic fall of more than 10 mmHg.
- Tachycardia, tachypnea, usually clear lungs, anxiety, cool skin.
- Jugular waveform without a y descent; the Kussmaul sign belongs more to constriction.
- ECG: low-voltage complexes and electrical alternans.
Pathophysiology
- The pericardium stretches little: a rapid collection, even if small, raises pressure sharply; a slow one can be large before causing symptoms.
- The low-pressure right chambers are the first to collapse in diastole.
- On inspiration the right ventricle fills more and pushes the septum toward the left (ventricular interdependence): systolic pressure falls, giving pulsus paradoxus.
- Venous pressure rises because blood cannot enter the heart.
Common causes
- Penetrating chest trauma and recent cardiac surgery or procedures.
- Viral, bacterial and tuberculous pericarditis (relevant in Colombia and the region), uremia, metastatic cancer.
- Proximal aortic dissection and free-wall rupture after infarction.
- Hypothyroidism, lupus and other autoimmune diseases.
Tests that confirm it
- Bedside echocardiography: effusion with diastolic collapse of the right atrium and ventricle and a dilated inferior vena cava without respiratory variation.
- Chest X-ray: 'water-bottle' silhouette only if the effusion is large and slow.
- It is a clinical and ultrasound diagnosis; other tests are not awaited in an unstable patient.
Test yourself
Think of the answer, then tap the question to see it.
What are the components of Beck triad?
Hypotension, jugular venous distension and muffled heart sounds.
Why does pulsus paradoxus appear in tamponade?
On inspiration the right ventricle fills more and, since the heart cannot expand, the septum compresses the left ventricle and stroke volume falls.
Which ECG finding suggests a large pericardial effusion with tamponade?
Electrical alternans, together with low-voltage complexes.
See it in 3D
The structures of Durgical's 3D anatomy where it is found.
Related
- Abnormal pulses: paradoxus, alternans, parvus et tardus, bounding
- Jugular venous pressure and the venous pulse
- Shock: the clinical signs and the types
- Heart sounds: S1, S2 and its splitting, S3 and S4
- Chest pain: ischemic, pericardial, pleural and other patterns
Related conditions
- Cardiac tamponade
- Acute pericarditis
- Aortic dissection
- Mechanical complications of myocardial infarction
- Pulmonary tuberculosis
- Constrictive pericarditis
Educational content on the clinical exam; it is learned and practised under supervision. It does not replace assessment by a health professional and is not for self-diagnosis.
Sources: Cardiac tamponade: MedlinePlus Medical Encyclopedia (MedlinePlus, U.S. National Library of Medicine, 2026); Pericarditis: MedlinePlus Medical Encyclopedia (MedlinePlus, U.S. National Library of Medicine, 2026); Shock: MedlinePlus Medical Encyclopedia (MedlinePlus, U.S. National Library of Medicine, 2026).
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Representative model, for educational purposes only.