Rapid Review·Cardiovascular
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PATHOLOGY
T2High yieldPericardial Disease: Pericarditis, Tamponade & Constriction
FA P317, 319-320
Focus on
One sac, three ways it goes wrong, and the bedside signs that tell them apart.
Key takeaways
Acute pericarditis
Presentation
sharp pleuritic chest pain, worse on inspiration and better sitting up and leaning forward, with a friction rub (triphasic: atrial systole, ventricular systole, early diastole) and possibly an effusion.ECG
diffuse ST elevation with PR depression, which is what separates it from a territorial STEMI. CXR may show an enlarged, globular silhouette with clear lung fields, because pericardial pressure squeezes the low-pressure right heart first, so there is no pulmonary edema.Causes
idiopathic, viral (coxsackie B, the most common infectious cause), post-MI, malignancy (breast metastases), autoimmune (SLE, RA, drug-induced lupus), uremia, and post-surgical or early post-radiation.Treatment
NSAID plus colchicine first line; glucocorticoids if refractory or autoimmune; dialysis if uremic.| Feature | Fibrinous | Hemorrhagic | Purulent |
|---|---|---|---|
| How common | Most common | Less common | Less common |
| Exudate | Serous, fibrin-containing | Blood mixed with fibrinous exudate | Frank pus, leukocyte-rich |
| Causes | Viral infection, MI, uremia, autoimmune disease | Malignancy, tuberculosis, after cardiac surgery, coagulopathy | S aureus (from skin), S pneumoniae (adjacent pneumonia), Candida (TPN, severe immunosuppression) |
Constrictive pericarditis
What it is
chronic inflammation causes pericardial fibrosis and calcification, limiting expansion so ventricular filling falls, EDV and cardiac output fall, and venous return backs up.Causes
usually idiopathic, also viral, post-cardiac surgery, or late after thoracic radiotherapy. TB is the most common cause in resource-limited settings.Presentation
dyspnea, peripheral edema, JVD, Kussmaul sign, pulsus paradoxus, a pericardial knock (ventricular filling stopping abruptly in early diastole, heard at the left sternal border), and a prominent y descent.| Feature | Acute pericarditis | Constrictive pericarditis |
|---|---|---|
| Presentation | Sharp pleuritic pain, better leaning forward | Dyspnea and edema |
| ECG | Diffuse ST elevation with PR depression | Non-specific |
| Physical | Friction rub | Kussmaul sign, pericardial knock, JVD |
| JVP | Normal | Prominent y descent |
| Causes | Idiopathic, coxsackie B, post-MI, uremia, autoimmune | Idiopathic, cardiac surgery, radiation; TB in resource-limited settings |
| Treatment | NSAID plus colchicine | Pericardiectomy |
Cardiac tamponade
What it is
compression of the heart by fluid (blood or effusion, classically malignant), reducing ventricular filling and cardiac output, with equilibration of diastolic pressures across all four chambers.Beck triad
hypotension, distended neck veins, distant heart sounds, plus tachycardia and pulsus paradoxus.ECG
low-voltage QRS and/or electrical alternans, the latter from the heart swinging within a large effusion.Echo
pericardial effusion, systolic RA collapse, diastolic RV collapse, IVC plethora.Treatment
pericardiocentesis or surgical drainage.| Feature | Cardiac tamponade | Constrictive pericarditis |
|---|---|---|
| JVP y descent | ABSENT | PROMINENT |
| Kussmaul sign | Usually absent | Present |
| Pulsus paradoxus | Prominent | Rare and less pronounced |
| ECG | Low voltage, electrical alternans | Non-specific |
| Treatment | Pericardiocentesis | Pericardiectomy |
The two bedside signs
Pulsus paradoxus
a fall in systolic blood pressure of more than 10 mm Hg during inspiration.- Mechanism: inspiration raises venous return and RV filling, and because pericardial compliance is limited, the interventricular septum bows toward the LV, reducing LV ejection.
- How to measure it: inflate the cuff above systolic and deflate slowly; the gap between the pressure where Korotkoff sounds first appear (expiration only) and where they are heard through the whole respiratory cycle is the paradox, abnormal above 10 mm Hg.
- Causes, by "pea COAT": Croup, OSA, Asthma, COPD, cardiac Tamponade, plus constrictive pericarditis.
Kussmaul sign
a paradoxical rise in JVP on inspiration. Normally inspiration lowers intrathoracic pressure, raises venous return, and lowers JVP.- Mechanism: impaired RV filling. The RV cannot accommodate the extra inspiratory venous return, so blood backs up into the vena cava.
- Causes: constrictive pericarditis, restrictive cardiomyopathy, right heart failure, massive pulmonary embolism, right atrial or ventricular tumours.
| Feature | Kussmaul sign | Pulsus paradoxus |
|---|---|---|
| What changes | JVP RISES on inspiration | Systolic BP FALLS more than 10 mm Hg on inspiration |
| Mechanism | RV cannot accommodate the extra venous return | Septum bows into the LV, reducing LV ejection |
| Classic for | Constrictive pericarditis, restrictive cardiomyopathy, right heart failure, massive PE | Cardiac tamponade (pea COAT) |
Hypotension, distended neck veins, muffled heart sounds, and the QRS height changes beat to beat. Diagnosis and treatment?
Cardiac tamponade (Beck triad plus electrical alternans from the swinging heart). Pericardiocentesis.
How it's tested
Diffuse ST elevation with PR depression is pericarditis, not a STEMI, because the change is global rather than territorial, and that ECG contrast is the most reliable question here. In a uremic patient the answer to the pericarditis is dialysis, not an anti-inflammatory.
The bedside signs separate the other two, and the exam builds distractors out of confusing them. Pulsus paradoxus, an inspiratory fall in systolic pressure over 10 mm Hg, points to tamponade, whereas Kussmaul sign, a paradoxical inspiratory RISE in JVP, points to constriction because the rigid pericardium cannot accommodate the extra venous return. The waveform agrees: the y descent is absent in tamponade and prominent in constriction. Tamponade is otherwise recognised by Beck triad with equalization of diastolic pressures, and constriction by a calcified pericardium on imaging with a pericardial knock.
Go deeper
First Aid 2026 — CV/Pathology (p.317, 319-320) · B&B — Pericardial disease · Mehlman — HY Cardio (Beck triad, pulsus paradoxus, Kussmaul, constriction vs tamponade)
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