Pericarditis - Causes, Symptoms and Treatments:

Pericarditis is an inflammation of the pericardium, the fibroserous sac that envelops, supports, and protects the heart. It occurs in both acute and chronic forms. Acute pericarditis can be fibrinous or effusive, with purulent, serous, or hemorrhagic exudate; chronic constrictive pericarditis is characterized by dense fibrous pericardial thickening. The prognosis depends on the underlying cause but is generally good in acute pericarditis, unless constriction occurs.

Causes of Pericarditis:

Common causes of this disease include bacterial, fungal, or viral infection (infectious pericarditis); neoplasms (primary, or metastases from lungs, breasts, or other organs); high-dose radiation to the chest; uremia; hypersensitivity or autoimmune disease, (such as acute rheumatic fever, systemic lupus erythematosus, and rheumatoid arthritis); postcardiac injury, such as myocardial infarction (MI), which later causes an autoimmune reaction (Dressler's syndrome) in the pericardium; trauma, or surgery that causes pericardial effusion; drugs, such as hydralazine or procainamide; and idiopathic factors (most common in acute pericarditis).

Less common causes include aortic aneurysm with pericardial leakage and myxedema with cholesterol deposits in the pericardium.

Signs and symptoms of Pericarditis:

In acute pericarditis, a sharp and often sudden pain usually starts over the sternum and radiates to the neck, shoulders, back, and arms. However, unlike the pain of MI, pericardial pain is often pleuritic, increasing with deep inspiration and decreasing when the patient sits up and leans forward, pulling the heart away from the diaphragmatic pleurae of the lungs.

Pericardial effusion, the major complication, may produce effects of heart failure (dyspnea, orthopnea, and tachycardia) as well as ill-defined substernal chest pain and a feeling of fullness in the chest.

Diagnosis for Pericarditis:

Because pericarditis often coexists with other conditions, diagnosis of the acute form depends on typical clinical features and elimination of other possible causes.

A classic symptom, the pericardial friction rub, is a grating sound heard as the heart moves. It can usually be auscultated best during forced expiration, while the patient leans forward or is on his hands and knees in bed.

Pericardial friction rub may have up to three components, corresponding to the timing of atrial systole, ventricular systole, and the rapid filling phase of ventricular diastole. Occasionally, it's heard only briefly or not at all. However, its presence, along with other characteristic features, is diagnostic of acute pericarditis.

In addition, if acute pericarditis has caused very large pericardial effusions, the physical examination reveals increased cardiac dullness and diminished or absent apical impulse and distant heart sounds. In patients with chronic pericarditis, acute inflammation or effusions do not occur only restricted cardiac filling.

Laboratory results reflect inflammation and may identify its cause. There is a normal or elevated white blood cell count, especially in infectious pericarditis, an elevated erythrocyte sedimentation rate, and slightly elevated cardiac enzyme levels with associated myocarditis. Cultures of pcricardial fluid obtained by open surgical drainage or cardiocentesis sometimes identifies a causative organism in bacterial or fungal pericarditis .

Electrocardiography shows the following changes in acute pericarditis: elevation of ST segments in the standard limb leads and most precordial leads without significant changes in QRS morphology that occur with MI, atrial ectopic rhythms such as atrial fibrillation, and diminished QRS complex in pericardial effusion .

Other pertinent laboratory studies include blood urea nitrogen level to check for uremia, antistreptolysin-O titers to detect rheumatic fever, and a purified protein derivative skin test to check for tuberculosis. In pericardial effusion, echocardiography is diagnostic when it shows an echo-free space between the ventricular wall and the pericardium.

Differential diagnoses include pulmonary emboli, angina, MI, pneumonia, and heart failure.

Treatment of Pericarditis:

The treatment goal is to relieve symptoms and manage underlying systemic disease.

In acute idiopathic pericarditis and post-thoracotomy pericarditis, treatment consists of bcd rest as long as fever and pain persist, and nonsteroidal anti-inflammatory drugs (NSAIDS), such as aspirin and indomethacin, to relieve pain and reduce inflammation. If these drugs fail to relieve symptoms, corticosteroids may be used. Although corticosteroids produce rapid and effective relief, they must be used cautiously because episodes may recur when therapy is discontinued. In post-MI pericarditis, aspirin, NSAIDS, and steroids should be avoided because they may interfere with myocardial scar formation.

Infectious pericarditis that results from disease of thc left pleural space, mediastinal abscesses, or scpticemia requires antibiotics (possibly by direct pericardial injection), surgical drainage, or both. Cardiac tamponade may require pericardiocentesis. Signs oftamponade include pulses paradoxus, neck vein distention, dyspnea, and shock.

Recurrent pericarditis may necessitate partial pericardectomy, which creates a window that allows fluid to drain into the pleural space. In constrictive pericarditis, total pericardectomy to permit adequate filling and contraction of the heart may be necessary. Treatment must also include management of rheumatic fever, uremia, tuberculosis, and other underlying disorders

Special considerations of Pericarditis:

1. Provide complete bed rest.

2. Assess pain in relation to respiration and body position to distinguish pericardial pain from myocardial ischemic pain.

3. Place the patient in an upright position to relieve dyspnea and chest pain. Provide analgesics and oxygen, and reassure the patient with acute pericarditis that his condition is temporary and treatable.

4. Monitor the patient for signs of cardiac compression or cardiac tamponade, possible complications of pericardial effusion. Signs include decreased blood pressure, increased central venous pressure, and pulses paradoxus. Because cardiac tamponade requires immediate treatment, keep a pericardiocentesis set handy whenever pericardial effusion is suspected.

5. Explain tests and treatments to the patient. If surgery is necessary, he should learn deep breathing and coughing exercises beforehand. Postoperative care is similar to that given after cardiothoracic surgery.