Definition and Classification
Definition
Pericarditis is an inflammation of the pericardium, the double-layered sac surrounding the heart.
Clinical classification is based on duration.
- Acute (< 6 weeks)
- Fibrinous
- Effusive (serous or serosanguinous)
- Subacute (6 weeks to 6 months)
- Effusive-constrictive
- Constrictive
- Chronic (> 6 months)
- Constrictive
- Adhesive (non-constrictive)
Epidemiology and Etiology
Epidemiology
- Reported in 0.1%–0.2% of hospitalized patients
- Found in 5% of patients admitted to the emergency department (ED) for nonischemic chest pain
Etiology
| Idiopathic (most common) | After exclusion of other causes |
|---|---|
| Viral infection |
|
| Bacterial infection |
|
| Fungal infection (very rare) |
|
| Autoimmune disease |
|
| Metabolic |
|
| Cardiovascular |
|
| Cancer |
|
| Drugs |
|
Pathophysiology
- Inflammatory cascade stimulates the release of fluid in the pericardial space, causing effusion.
- Rapid accumulation of large amounts of fluid in the pericardial space can cause cardiac tamponade, compromising cardiac output and potentially resulting in obstructive shock.
- Constrictive pericarditis is characterized by a thickened and scarred pericardial sac that lies around the heart and prevents proper diastolic filling.
Clinical Presentation and Diagnosis
Typical clinical presentation
- Patient presents with central chest pain that worsens during inspiration or when lying flat. Leaning forward while sitting may relieve the pain.
- Fever can be present.
- In 50% of cases, a pericardial friction rub (scratching sound during systole and diastole) can be heard upon auscultation.
| Features | Acute | Chronic | Constrictive |
|---|---|---|---|
| Pain |
|
| None |
| Other symptoms |
| May have dyspnea |
|
| Physical examination |
|
|
|
| ECG |
| Electrical alternans7 with a large effusion |
|
| Echocardiography8 | Pleural effusion | Pleural effusion | Pericardial thickening |
| Tamponade9 | With rapid fluid accumulation | Uncommon | Never |
| Comments | Elevated cardiac biomarkers can occur, further simulating a diagnosis of acute MI. |
- Pleuritic pain: pain that is exacerbated with inspiration or exhalation and reduced or eliminated by holding respirations
- Pericardial friction rub: a rasping, scratching, or grating sound with up to 3 components per cardiac cycle and best heard during expiration with the patient leaning forward
- Pericardial knock: an early third heart sound
- Kussmaul’s sign: absence of normal decline in jugular venous pressure with inspiration; also seen in tricuspid stenosis, right ventricular infarction, and restrictive cardiomyopathy
- Paradoxical pulse: a drop by > 10 mm Hg in systolic blood pressure (SBP) during inspiration (i.e., difference between the first SBP sound heard during exhalation and the first SBP sound heard audible throughout the respiratory cycle > 10 mm Hg)
- Subsequent ECG changes include: ST-segment elevation returns to normal after several days (stage 2), followed by T-inversions (stage 3), and complete normalization of ECG after weeks to months (stage 4)
- Electrical alternans: alternating QRS amplitudes
- Echocardiography for pericarditis: most widely used modality (CT and MRI are more accurate for pericardial disease)
- Tamponade: pericardial effusion, usually of rapid onset, exceeding ventricular filling pressures and causing collapse of the heart with a markedly reduced cardiac output
Etiology-specific features
- Viral or acute idiopathic pericarditis:
- Chest pain 1–2 weeks after a viral-like illness is suggestive.
- Must exclude acute MI, postcardiac injury, collagen vascular disease, drugs, pyogenic pericarditis, etc.
- Most frequent complication is relapsing pericarditis.
- Postcardiac injury acute pericarditis:
- 1–4 weeks after a cardiac operation or blunt/penetrating trauma
- Tuberculous pericarditis:
- Common cause of chronic pericardial effusion in developing countries
- In a patient with tuberculosis or systemic illness and large cardiac silhouette: positive fluid culture or pericardial biopsy revealing caseating granuloma confirms the diagnosis.
- Uremic pericarditis:
- Seen with severe renal failure or in patients on chronic dialysis
ECG showing diffuse ST-segment elevation with upward concavity without T-wave inversions in a patient with acute pericarditis
Image: “Diffuse STE in leads I, II, III, aVF, V2-V6 with ST depression in leads aVR and V1, compatible with acute pericarditis” by Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA. License: CC BY 3.0
ECG showing diffuse ST-segment elevation and the absence of reciprocal ST-segment depression
Image by Lecturio.
Management
Viral or idiopathic pericarditis
- Oxygen and analgesia
- High-dose aspirin/nonsteroidal anti-inflammatory drugs (NSAIDs) (e.g., ibuprofen, indomethacin) plus gastric protection
- Adjuvant therapy with colchicine enhances response and reduces the recurrence rate.
- Short-term glucocorticoids can be used if NSAIDs/colchicine are ineffective or contraindicated.
Constrictive pericarditis
- Complete pericardial resection (pericardiectomy) is the only definitive treatment and is best performed as early as possible
- Diuretics to reduce symptoms leading to surgery
Specific treatments
- Initiation or intensification of dialysis in addition to NSAIDs in uremic pericarditis
- Antibiotics if an underlying infection is found
- Antituberculous therapy ± pericardiectomy
Differential Diagnoses
- Stable and unstable angina: paroxysmal chest pain or discomfort caused by myocardial ischemia. Stable angina is characterized by a short duration of the complaints that are often associated with triggers like physical activity or stress. In unstable angina, symptoms are present even at rest. Most individuals with angina have coronary heart disease.
- MI: myocardial cell death due to ischemia of the myocardial tissue caused by a complete obstruction or drastic constriction of the coronary artery. Typical symptoms include chest pain that may radiate to the left arm, jaw, neck, and upper back, as well as nausea and vomiting. ST-elevation on ECG can be present (STEMI) or absent (NSTEMI).
- Aortic stenosis: a narrowing of the aortic valve aperture, characterized by a narrowed left ventricular outflow tract and obstruction of blood flow into the aorta
- Esophagitis: an inflammation of the esophageal lining, which can be caused by gastroesophageal reflux disease (GERD), infections, drugs, and allergic reactions.
- Pancreatitis: an inflammation of the pancreas that typically causes epigastric pain that radiates to the back
- Pneumonia: acute or chronic inflammation of lung tissue most commonly caused by infection with bacteria, viruses, or fungi
- Pleuritis: also known as pleurisy, an inflammation of the pleura that lines the lungs. May be caused by a viral infection (most common), pneumonia, lung cancer, autoimmune disease, or pulmonary embolism
- Tuberculosis: a disease caused by Mycobacterium tuberculosis, which usually attacks the lungs but can also damage other parts of the body. Presents with fever, weight loss, night sweats, and a productive cough
- Pneumothorax: a collection of air in the pleural space that causes the lung to collapse due to the loss of negative pressure. Presents with pleuritic chest pain, dyspnea, tachycardia, and reduced breath sounds on the ipsilateral side
- Herpes zoster: a dermatomal rash with painful blistering, preceded by sharp burning pain, caused by the reactivation of the varicella-zoster virus. It usually affects dermatomes T3 through L3.
