Cardiac Tamponade
Cardiac Tamponade
Definition: Clinical state where pericardial fluid compresses the heart and compromises cardiac output.
Normal pericardial fluid volume: 15-30 mL
Echocardiography findings
- RA systolic collapse
- RV diastolic collapse
- IVC plethora
- Exaggeration of respirophasic changes in flow velocities across TV and MV
Systematic review of 8 studies with a total of 300 patients
| Finding | Sensitivity | Specificity |
|---|---|---|
| Clinical history | | | |
| Dyspnea | 87-88% | |
| Physical exam | | | |
| Tachycardia | 77% | |
| Hypotension | 26% | |
| Diminished heart sounds | 28% | |
| Elevated JVP | 76% | |
| ECG | | | |
| Low voltage | 42% | |
| Electrical alternans | 16-21% | |
| ST elevation | 18-30% | |
| PR depression | 18% | |
| Chest xray | | | |
| Cardiomegaly | 89% | |
| Pulsus paradoxus | | | |
| > 12 mmHg | 98% | 83% |
| > 10 mmHg | 98% | 70% |
Pulsus paradoxus Likelihood Ratios
| Measurement | Positive LR | Negative LR |
|---|---|---|
| > 12 mmHg | 5.9 | 0.03 |
| > 10 mmHg | 3.3 | 0.03 |
Use below Fagan nomogram.
Fagan Nomogram
- Draw a connecting your pre-test probability and your likelihood ratio.
- This provides you with your post-test probability.
References
- Roy CL et al. Does This Patient With a Pericardial Effusion Have Cardiac Tamponade? JAMA. 2007;297:1810-8. [PubMed]
