Pericardial Diseases

Pericardial disease is an important consideration in patients presenting with cardiopulmonary symptoms. The understanding of pericardial disease, structural heart disease is important as these diseases not only cause significant morbidity, but they may also mimic other diseases which may require alternative treatment.

Definitions

• Pericarditis is an inflammation of the pericardial layer surrounding the heart.
• A pericardial effusion is an abnormal accumulation of fluid in the pericardial space.
• Cardiac tamponade refers to an impairment of cardiac output caused by a pericardial effusion.
• Scarring and thickening of the pericardium may cause constrictive pericarditis, a rare complication of pericarditis.

Epidemiology/Pathophysiology

• Pericarditis has multiple etiologies including infection, malignancy, uremia, connective tissue disorders, trauma, myocardial infarction, or medications. Pericarditis may also be idiopathic, but it is unclear if these represent undiagnosed viral pericarditis.
• Pericarditis that occurs post myocardial infarction is called Dressler's syndrome.
• Dressler's syndrome is associated with large, anterior infarctions and may indicate a poor long-term prognosis.
• Pericardial inflammation causes an increase in pericardial fluid beyond the 15-50 ml normally present. As pericardial fluid accumulates, intrapericardial pressure increases exponentially.
• Cardiac tamponade occurs when intrapericardial pressures rise to a level such that diastolic filling of the heart is impaired. This leads to an increase in central venous pressure and a decreased cardiac output.
• Constrictive pericarditis may lead to similar hemodynamic abnormalities as cardiac tamponade.

History and Physical Examination

• Pericarditis may be asymptomatic. Presenting symptoms correlate with the etiology of pericarditis.
• Acute viral pericarditis typically presents with fevers, myalgias, and fatigue.
• Chest pain is common in acute pericarditis. The pain is classically sharp and pleuritic.
• It is often exacerbated by leaning forward and relieved by supine positioning. Radiation of the pain to the trapezius ridge is a specific finding.
• As a pericardial effusion enlarges and tamponade begins, symptoms of increased venous pressure and decreased cardiac output (dyspnea, orthopnea, syncope) present.
• A pericardial friction rub is the classic physical finding of pericarditis. Friction rubs have been described in many ways such as "creaky" or "velcro-like." They are best heard with the bell of the stethoscope and can be heard anywhere over the pericardium. Friction rubs are transient and change in quality over time. Thus, the absence of a friction rub does not rule out pericarditis.
• As cardiac tamponade develops, signs of increased venous pressure (JVD, hepatomegaly) and decreased cardiac output (hypotension) develop.
• Beck's triad of hypotension, JVD, and muffled heart sounds is specific for cardiac tamponade, but rarely present.
• Pulsus paradoxus, a decrease of systolic blood pressure of at least 10 mm Hg during inspiration, is another sign of cardiac tamponade, but its presence is not sensitive enough to rule out the diagnosis.

  Laboratory and Studies

• Laboratory tests do not play a major role in the evaluation of pericardial disease.
• An increased ESR is a nonspecific test that is usually elevated in pericarditis.
• Cardiac enzymes may be elevated in pericarditis indicating a concurrent inflammation of the underlying myocardium.
• The electrocardiogram is an important tool in the evaluation of patients with pericardial disease. As these patients often present with chest pain that may not be indistinguishable from ischemic chest pain, subtle differences in the EKG may dramatically change treatment.
• The EKG typically evolves through four stages in acute pericarditis:
• Stage 1, hours to days after symptom onset, demonstrates a diffuse concave upward elevation of the ST segment in all leads but AVR and V1. The PR segment is depressed in 80% of patients. There are generally no T-wave abnormalities.
• In stage 2 there is a normalization of the above ST and PR segments
• Stage 3 demonstrates diffuse deep, symmetric T-wave depressions.
• Stage 4 is a normalization of the T-wave depressions.
• Electrical alternans, the finding of changing QRS polarity with every other beat, is a specific finding for large, chronic pericardial effusions most commonly caused by malignancy.
• Chest X-ray may demonstrate cardiomegaly or a "water bottle" heart with large pericardial effusions.
• Echocardiography is a fast, reliable method to diagnose pericardial effusions.
  Echocardiography can detect as little as 15 ml of fluid and can be done at bedside in unstable patients. Echocardiography is a sensitive test for signs of cardiac tamponade including right ventricular diastolic collapse and IVC dilation with lack of inspiratory collapse.

  ED Management

• Treatment of acute pericarditis includes pain control and control of inflammation with NSAIDS. Treatment may continue on an outpatient basis in stable patients, but may require inpatient management in patients with severe pain, significant pericardial effusions, or any signs of hemodynamic instability.
• Treatment of pericardial effusions is dependent on the etiology. Uremic pericarditis with effusion, for example, is an indication for dialysis.
• Cardiac tamponade is treated with drainage of pericardial fluid via pericardiocentesis or operative drainage.
• Constrictive pericarditis is treated with operative removal of the pericardium.