Pericarditis

Pericarditis
An ECG showing pericarditis. Note the ST elevation in multiple leads with slight reciprocal ST depression in aVR.
Classification and external resources
ICD-10	I01.0, I09.2, I30–I32
ICD-9	420.0, 420.90, 420.91, 420.99, 423.1, 423.2
DiseasesDB	9820
MedlinePlus	000182
eMedicine	med/1781 emerg/412
MeSH	D010493

Pericarditis is an inflammation of the pericardium (the fibrous sac surrounding the heart). A characteristic chest pain is often present.

The causes of pericarditis are varied, including infections of the pericardium by viruses or bacteria (e.g., Mycobacterium tuberculosis), idiopathic causes, uremic pericarditis, post-infarct pericarditis (within 24 hours of a heart attack), or Dressler's syndrome (weeks to months after a heart attack).

Classification

Pericarditis can be classified according to the composition of the fluid that accumulates around the heart.^[1]

Types of pericarditis include the following:

• serous
• purulent
• fibrinous
• caseous
• hemorrhagic

Acute vs. chronic

Depending on the time of presentation and duration, pericarditis is divided into "acute" and "chronic" forms. Acute pericarditis is more common than chronic pericarditis, and can occur as a complication of infections, immunologic conditions, or even as a result of a heart attack (myocardial infarction). Chronic pericarditis however is less common, a form of which is constrictive pericarditis. The following is the clinical classification of acute vs. chronic:

• Clinically: Acute (<6 weeks), Subacute (6 weeks to 6 months) and Chronic (>6 months)

Signs and symptoms

Figure A shows the location of the heart and a normal heart and pericardium (the sac surrounding the heart). The inset image is an enlarged cross-section of the pericardium that shows its two layers of tissue and the fluid between the layers.
Figure B shows the heart with pericarditis. The inset image is an enlarged cross-section that shows the inflamed and thickened layers of the pericardium.^[2]

Substernal or left precordial pleuritic chest pain with radiation to the trapezius ridge (the bottom portion of scapula on the back), which is relieved by sitting up and bending forward and worsened by lying down (recumbent or supine position) or inspiration (taking a breath in), is the characteristic pain of pericarditis.^[3] The pain may resemble the pain of angina pectoris or heart attack, but differs in that pain changes with body position, as opposed to heart attack pain that is pressure-like, and constant with radiation to the left arm and/or the jaw. Other symptoms of pericarditis may include dry cough, fever, fatigue, and anxiety. Due to similarity to myocardial infarction (heart attack) pain, pericarditis can be misdiagnosed as an acute myocardial infarction (a heart attack) solely based on the clinical data and so extreme suspicion on the part of the diagnostician is required. Acute myocardial infarction (heart attack) can also cause pericarditis, but the presenting symptoms often differ enough to warrant diagnosis. The following table organizes the clinical presentation of pericarditis:^[3]

Physical examinations

The classic sign of pericarditis is a friction rub heard with a stethoscope on the cardiovascular examination usually on the lower left sternal border.^[3] Other physical signs include a patient in distress, positional chest pain, diaphoresis (excessive sweating), and possibility of heart failure in form of pericardial tamponade causing pulsus paradoxus, and the Beck's triad of low blood pressure (due to decreased cardiac output), distant (muffled) heart sounds, and distension of the jugular vein (JVD).

Acute complications

Pericarditis can progress to pericardial effusion and eventually cardiac tamponade. This can be seen in patients who are experiencing the classic signs of pericarditis but then show signs of relief, and progress to show signs of cardiac tamponade which include decreased alertness and lethargy, pulsus paradoxus (decrease of at least 10 mmHg of the systolic blood pressure upon inspiration),low blood pressure (due to decreased cardiac index), (jugular vein distention from right sided heart failure and fluid overload), distant heart sounds on auscultation, and equilibration of all the diastolic blood pressures on cardiac catheterization due to the constriction of the pericardium by the fluid.

In such cases of cardiac tamponade, EKG or Holter monitor will then depict electrical alternans indicating wobbling of the heart in the fluid filled pericardium, and the capillary refill might decrease, as well as severe vascular collapse and altered mental status due to hypoperfusion of body organs by a heart that can not pump out blood effectively.

The diagnostic test for cardiac tamponade, is trans-esophageal echocardiography (TEE) although trans-thoracic echocardiography (TTE) can also be utilized in cases where there is a high suspicion of aortic dissection and high blood pressure, or in patients where esophageal probing is not feasible. Chest X-ray can depict a "water bottle" appearance of the heart in tamponade, although chest X-ray is neither specific enough nor accurate enough in the acute setting. Of note is the fact that chest x-ray can be entirely normal in acute pericardial effusion/tamponade and therefore should not be relied upon as the sole diagnostic tool.

Causes

Infectious

Pericarditis may be caused by viral, bacterial, or fungal infection. The most common viral pathogen has traditionally been considered to be coxsackievirus based on studies in children from the 1960s, but recent data suggest that adults are most commonly affected with cytomegalovirus, herpesvirus, and HIV.^[4][5] Pneumococcus or tuberculous pericarditis are the most common bacterial forms. Anaerobic bacteria can also be a rare cause.^[6] Fungal pericarditis is usually due to histoplasmosis, or in immunocompromised hosts Aspergillus, Candida, and Coccidioides. The most common cause of pericarditis worldwide is infectious pericarditis with Tuberculosis.

Other

• Idiopathic: No identifiable etiology found after routine testing.
• Immunologic conditions including systemic lupus erythematosus (more common among women) or rheumatic fever
• Myocardial infarction (Dressler's syndrome)
• Trauma to the heart, e.g. puncture, resulting in infection or inflammation
• Uremia (uremic pericarditis)
• Malignancy (as a paraneoplastic phenomenon)
• Side effect of some medications, e.g. isoniazid, cyclosporine, hydralazine, warfarin, and heparin
• Radiation induced
• Aortic dissection
• Tetracyclines
• Postpericardiotomy syndrome: Usually after CABG surgery

Diagnosis

An ECG showing pericarditis.

Laboratory tests

This diagram depicts the elevation of respective cardiac markers in a myocardial infarction (heart attack). Although this diagram is only for heart attack, elevated values of these markers might be seen in pericarditis.

Laboratory values can show increased urea (BUN), or increased blood creatinine in cases of uremic pericarditis. Generally however, laboratory values are normal, but if there is a concurrent myocardial infarction (heart attack) or great stress to the heart, laboratory values may show increased cardiac markers like Troponin (I, T), CK-MB, Myoglobin, and LDH1 (Lactase Dehydrogenase isotype 1). The preferred initial diagnostic testing is the EKG which will show a 12-lead electrocardiogram with diffuse, non-specific, concave ("saddle-shaped"), ST segment-elevations all leads except aVR and V1^[3] and PR segment-depression possible in any lead except aVR;^[3] sinus tachycardia, and low-voltage QRS complexes can also be seen if there is subsymptomatic levels of pericardial effusion. The PR depression is often seen early in the process as the thin atria are affected more easily than the ventricles by the inflammatory process of the pericardium.

Since the mid-19th Century, retrospective diagnosis of pericarditis has been made upon the finding of adhesions of the pericardium.^[7] When pericarditis is diagnosed clinically, the underlying cause is often never known; it may be discovered in only 16-22 percent of patients with acute pericarditis.

Imaging

• 

  Ultrasounds showing a pericardial effusion in someone with pericarditis

• 

  A pericardial effusion as seen on CXR in someone with pericarditis

Treatment

The treatment in viral or idiopathic pericarditis is with aspirin,^[3] or non-steroidal anti-inflammatory drugs (NSAIDs such as ibuprofen).^[8] Colchicine may be added to the above^[8] as it decreases the risk of further episodes of pericarditis.^[9]

Severe cases may require one or more of the following:

• pericardiocentesis to treat pericardial effusion/tamponade
• antibiotics to treat tuberculosis or other bacterial causes.
• steroids are used in acute pericarditis but are not favored because they increase the chance of recurrent pericarditis.
• in rare cases, surgery
• in cases of constrictive pericarditis, pericardiectomy

References

General References

External links

• Pericarditis — Cleveland Clinic
• Pericarditis — National Library of Medicine
• Pericarditis — National Heart Lung Blood Institute