The pericardial space provides lubrication and anchoring of the heart, but beyond that the pericardium has no major vital function and can even be safely removed. It does probably help prevent spread of infection to the heart, but can itself become diseased. The most common cause of acute pericarditis is viral infection, such as a Coxsackie virus. But in over 80% of cases of pericarditis, no specific cause is ever found.
Classic symptoms include a sharp pleuritic chest pain, worse with inspiration. On physical examination a 2 or 3 component pericardial rub may be present. The classic ECG chart shows diffuse concave upward ST elevation, upright T-waves and PR depression. At times, this can look like acute myocardial infarction.
And in fact, some cases are caused by acute MI. Serious causes account for pericarditis often enough that every case demands close examination. Other causes include aortic dissection, trauma from catheter manipulation or bypass, endocarditis and cancer. Primary heart cancer such as a sarcoma is possible, but pericardial effusion is far more commonly caused by metastatic disease. Inflammatory causes include infection (Coxsackie virus, tuberculous pericarditis, HIV, bacterial uremic pericarditis); radiation, and autoimmune processes such as lupus. Metabolic causes include hypothyroidism and renal failure.
Most patients with acute pericarditis have a benign course, but indicators of a poorer prognosis and more long-term consequences include female sex, large effusions, clinical tamponade, and failure of NSAIDs with increased use of steroids.
A trial of 453 patients with acute pericarditis1 revealed that complications occurred in about one in five, including recurrence in 18% and tamponade in 3%. The classic tamponade presentation includes hypotension, tachycardia, elevation of jugular venous pressure (JVP) and a normal chest exam. Echo features of tamponade include right ventricular and right atrial diastolic collapse, and many features of constriction. Constriction occurred in 2% (echo features include restrictive diastolic ventricular filling pattern, normal medial E’ on tissue Doppler greater than 8-10 cm/s, enlarged and non-collapsing inferior vena cava, thick pericardium). Clinically, these patients often present with unexplained right-sided congestive heart failure with elevated JVP.
Management — a new gold standard
Acute management is to rule out serious cases, such as concomitant myocarditis and tamponade. Clinical examination should look for elevated neck veins and hypotension. When in doubt, an echocardiogram can rule out pericardial effusion.
The traditional treatment for uncomplicated cases is NSAIDs for 1 month. The COPE (Colchicine for Acute Pericarditis)2 trial looked at the use of colchicine for acute pericarditis. Adding 3 months of colchicine 0.6 mg twice daily to an NSAID reduced recurrence rates from 32% to 10%. Most clinicians are still unaware of these findings. The CORE trial (Colchicine for Recurrent Pericarditis)3 demonstrated that the combination of colchicine and aspirin versus aspirin alone decreased recurrence of pericarditis.
Prednisone should be avoided, except when recommended by specialists in patients with connective tissue disorders. Relapsing pericarditis may very rarely require pericardectomy.
In summary, acute pericarditis is often related to viral illnesses and the cause usually isn’t found. A good history and physical examination along with an ECG ± echocardiogram is sufficient for most patients. Significant pericardial effusion, especially with blood in the pericardial space, requires a closer look. NSAIDs will manage most cases and colchicine reduces recurrence. If it doesn’t, it may point to a more serious underlying cause.
Gregory P. Curnew, MD, FRCPC is Associate Professor at McMaster University in Hamilton, ON, and Director of the Coronary Care Unit at Hamilton General Hospital.