Introduction
Cardiac tamponade is characterized by the accumulation of pericardial fluid under pressure.
Clinical features
Classical features - Beck's triad:
Other features:
- Hypotension
- Raised JVP
- Muffled heart sounds
Other features:
- Dyspnoea
- Tachycardia
- An absent Y descent on the JVP - this is due to the limited right ventricular filling
- Pulsus paradoxus - an abnormally large drop in BP during inspiration
- Kussmaul's sign - much debate about this
- ECG: electrical alternans
Differential diagnosis
The key differences between constrictive pericarditis and cardiac tamponade are summarised in the table below:
| Cardiac tamponade | Constrictive pericarditis | |
|---|---|---|
| JVP | Absent Y descent | X + Y present |
| Pulsus paradoxus | Present | Absent |
| Kussmaul's sign | Rare | Present |
| Characteristic features | Pericardial calcification on CXR |