Pericarditis

Picture of the Heart in the Pericardial Sac

Pericarditis describes the condition where the thin membrane lining the heart becomes inflamed. Most often, acute pericarditis is self-limiting and will resolve within a few weeks. However, it may recur and is considered chronic if the symptoms persist for more than 6-12 months. Some people that develop pericarditis can have complications such as fluid accumulation around the heart (pericardial effusion) or heart compression (pericardial constriction) that may require emergency or surgical interventions.

The pericardium is a thin membrane that encloses the heart and the base of the great vessels of the heart (aorta, vena cava, pulmonary artery and pulmonary vein). It is composed of to layers. The visceral layer is attached to the heart surface and then folds back on itself to form the parietal layer. This forms a small place that normally holds less than 50cc of fluid.

The pericardium holds the heart in its appropriate position in the chest and protects it from infection or tumors that might spread directly from other organs near the heart, such as the lung or esophagus. The pericardium also prevents the heart from dilating too much, which allows the heart muscle fibers to maintain their ideal length to contract or squeeze forcefully.

Most often, pericarditis is self-limiting with medical care directed toward controlling the major symptom of pain. However, chronic inflammation of the pericardium can cause scarring that prevents the heart from beating appropriately and surgery may be required.

Inflammation can occur in many places in the heart. Pericarditis describes an inflammation of the membrane lining of the heart. It is different than myocarditis (inflammation of the heart muscle) and endocarditis (inflammation of the heart valves).

The most common cause of pericarditis is idiopathic, meaning the reason cannot be determined. However, listed below are some known causes of pericarditis.

Infection

Infections may cause inflammation of the pericardium and viruses such as the Coxsackie B, adenovirus and influenza A and B are most common.

Other viruses can be involved, examples include:

• Epstein-Barr virus that causes infectious mononucleosis,
• herpes simplex type 1,
• measles,
• mumps, and
• human immunodeficiency virus (HIV).

Even less commonly, bacterial infections such as tuberculosis may cause pericarditis and often bacterial infections are associated with the development of constrictive pericarditis (see below). Other infectious causes include parasites and fungi.

Inflammatory Diseases

Illnesses that can cause generalized inflammation in the body can also cause inflammation of the pericardium. Examples of these may include:

• rheumatoid arthritis,
• systemic lupus erythematosus,
• scleroderma, and
• sarcoidosis.

Other Illnesses

Other illnesses may contribute or cause pericarditis and examples include:

• Kidney disorders including patients on chronic dialysis.
• Patients having a heart attack can develop pericardial inflammation because of the underlying heart muscle damage. This may occur within days of the heart attack or may be delayed by 2-3 weeks. Dressler's syndrome describes delayed pericarditis after heart attack or heart surgery. It may be associated with lung inflammation and effusion (fluid accumulation).
• Hypothyroidism or decreased thyroid function may be associated with pericardial inflammation.
• Cancers and other malignancies can be associated with pericarditis. The pericardium can be inflamed by direct extension of cancer cells from nearby structures or there can be hematogenous spread of abnormal cancer cells through the blood stream. Lung cancer, breast cancer, leukemia and lymphoma, both Hodgkin's and non-Hodgkin's are the common cancer causes of pericarditis.

Other causes

• Trauma that injures the heart can cause inflammation of the pericardium. The injury can be a direct blow to the chest causing a cardiac contusion or it can be a penetrating injury to the chest and heart.
• Radiation cancer therapy can cause inflammation of the pericardium.
• Pericarditis can be an uncommon side effect of some medications. Examples include some cancer chemotherapy medications, a few heart medications (for example, procainamide [Procan SR, Procanbid, Pronestyl, Pronestyl-SR], hydralazine [Apresoline], phenytoin [Dilantin, Dilantin Infatabs, Dilantin Kapseals, Dilantin-125, Phenytek, Phenytoin Sodium Prompt]) andsmallpox vaccine (Dryvax).

• Chest pain is the most common pericarditis symptom that causes a patient to seek medical care. The pain is usually sharp and pleuritic, meaning that it hurts worse to take a deep breath. It is often worse when lying flat and is eased somewhat by leaning forward. The pain can radiate to the back or left shoulder.
• Fever, weakness, and malaise may be present, as with any other inflammatory process in the body.
• If the pericarditis persists, fluid can accumulate around the heart, termed a pericardial effusion. The effusion can raise the pressure inside the pericardium causing cardiac tamponade that prevents the heart muscle from contracting and beating adequately. This can cause symptoms of shortness of breath, weakness, syncope (fainting), and in some people, death.
• Constrictive pericarditis occurs when the pericardium scars down and adheres to the heart surface; it can prevent the heart from expanding to receive blood returning from the body. This type of pericarditis can present with swelling (edema) of the feet, ankles and legs.

The diagnosis of pericarditis begins with a careful history taken by the health care practitioner. While most cases of pericarditis have an unknown cause, it is important to explore situations where an underlying disease can be treated. History of recent illness, heart attack, surgery, or underlying inflammatory illness may give a clue as to the potential cause of pericarditis.

When a patient has symptoms with chest pain, the health care practitioner will always be concerned about other potential diagnoses including atherosclerotic heart disease with angina or heart attack, aortic dissection,pulmonary embolism, as well as less life-threatening illnesses such as esophagitis and gastritis.

While physical examination will concentrate on the heart examination, general assessment of the patient may find the presence of fever, a rapid heartbeat (tachycardia) or rapid breathing rate (tachypnea).

Abnormal heart sounds may be heard when using a stethoscope to listen to the heart. Hearing a friction rub often confirms the presence of pericarditis, though not the cause. A friction rub occurs when the two inflamed pericardial surfaces, rub against each other with every heart beat. The friction rub which can be difficult to hear, may sometimes be better heard when the patient leans forward.

Beck's triad describes the signs of cardiac tamponade on physical examination. Low blood pressure, jugular vein distention in the neck and muffled heart tones make up the triad. The tamponade prevents the heart from distending to accept blood returning from the body, causing veins to distend. The heart cannot pump blood appropriately causing the blood pressure to fall and the fluid decreases the heart sound volume making it difficult to he heard by the health care practitioner.

An electrocardiogram (EKG) may reveal common electrical conduction abnormalities that are seen in pericarditis.

Chest X-rays may be normal, but if there is a significant pericardial effusion, the heart shape may be abnormal. It is sometimes described as globular or flask shaped.

An echocardiogram or ultrasound exam of the heart may demonstrate fluid or effusion. It is an emergent test if cardiac tamponade is suspected.

While the diagnosis of pericarditis is often made clinically and confirmed with an electrocardiogram or other tests such as CT scan, ultrasound, or echocardiogram, blood tests may be helpful in the diagnosing the underlying cause.

• A complete blood count (CBC) may reveal an elevated white blood cell count associated with a potential bacterial infection, though the white cell count may be elevated due to stress.
• Blood chemistry tests can evaluate kidney function to explore for uremia (excessive amounts of urea in the blood) or kidney failure.
• Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are non-specific markers for inflammation within the body.
• Cardiac enzymes such as troponin ormyoglobin may be measured since pericarditis may be associated with heart attack or myocarditis (an inflammation of the heart muscle).
• Other laboratory tests may be considered depending upon the situation and may include blood cultures for bacterial or viral infections,tuberculin testing, andthyroid function tests among others.

Other tests may be used to further define the extent and in some cases, the source of pericardial fluid. Most frequently, CT or MRI scans of the heart and surrounding structures are examined.

In certain situations such as pericardial tamponade, pericardiocentesis may be performed. A long needle is inserted through the chest wall into the pericardial space and fluid is removed to reduce pressure on the heart muscle tissue and allow the heart to beat properly. This fluid can be sent for analysis to explore possible infections, abnormal cells, and other causes of inflammation.

The patient who seeks for medical care complaining of chest pain and shortness of breath is often evaluated for serious heart and/or lung problems. Oxygen is often supplied, a monitor is used to assess heart rate and rhythm and an electrocardiogram is performed to look for potential acute heart attack. Vital signs, including blood pressure, heart rate, respiratory rate, temperature and oxygen saturation may be performed.

If the health care practitioner has no evidence for concern about a potential life-threatening situation, a more thorough but perhaps less emergent approach to pericarditis treatment may be considered.

If an individual experiences chest pain at home, usually it is best for the individual to seek medical care particularly if the pain is new to the person. Chest pain may be an indicator of a life-threatening illness such as heart attack. It may be appropriate to take anaspirin and seek emergency medical care.

Ibuprofen is the drug of choice for pericarditis. It works as an anti-inflammatory minimizing pericardial irritation. It also acts as an analgesic pain medication. However, ibuprofen is not used if the person has a heart attack with pericarditis because it may interfere with cardiac healing.

Other medications may be considered depending upon the underlying cause of the pericarditis. It is important to note that the vast majority of cases are idiopathic and have no recognizable cause.

If cardiac tamponade occurs, pericardiocentesis may be performed to withdraw fluid from the pericardial space. This is both therapeutic and potentially diagnostic, since the fluids can be analyzed to assist in diagnosing the cause of pericarditis. If the pericardial fluid re-accumulates, it may be necessary for a surgeon to remove a small area of the pericardium to allow chronic drainage. This procedure is called a pericardial window.

In patients with constrictive pericarditis, the pericardium prevents the heart from filling and beating adequately. Pericardectomy is a treatment option, where the surgeon strips the pericardium from the surface of the heart.

After the diagnosis of pericarditis, follow up with the health care practitioner is recommended to monitor symptoms and to screen for potential pericardial effusion, cardiac tamponade, and constrictive pericarditis.

It is also important that any underlying disease be addressed and monitored.

Since most causes of pericarditis are idiopathic and are never found, it is difficult to predict or prevent this disease process.

Pericarditis usually resolves spontaneously within 3 months, though there is a possibility of recurrence intermittently for years. The use of ibuprofen may all that is required to combat flares of the disease. Pericarditis associated with tuberculosis, pus-producing bacterial infections, and cancer usually has a more guarded prognosis.