Pericarditis - Myocarditis

This young man came to the emergency department with 12 hours of continuing anterior chest pain. His pain was precipitated by exertion and movement. There was no significant pleuritic component. He is not a smoker and denied history of illicit drug or cocaine use. His CPK-MB and Troponin were both abnormal. The ECG shown above was the first one taken. At this point, he was having 10 of 10 chest pain with minimal relief from nitroglycerin and morphine. Fearing an Acute Myocardial Infarction (Heart Attack), the patient was taken emergently for cardiac catheterization. Fortunately, coronary arteriography showed normal coronary arteries without any evidence of atherosclerosis. His left ventricular function was abnormal and the left ventricular cavity appeared slightly dilated. His pain persisted, off and on, for the next 2-3 days. During this time, his cardiac enzymes continued to rise and the ECG abnormalities worsened. Five days later, echocardiography showed global left ventricular dysfunction.

The patient left the hospital with a diagnosis of Pericarditis/Myocarditis. Eight weeks later, his echocardiogram showed normal left ventricular function. His pain disappeared completely 96 hours after admission to the hospital.

The Electrocardiographic changes are consistent with pericarditis-particularly because of the diffuse nature of the ST segment changes. Note ST segment elevation in leads I, II, aVL, V2-V6. If this were due to ischemic changes, it would represent massive coronary ischemia transcending multiple coronary artery distributions. While PR depression is not clearly seen in the ECG above, it developed on subsequent cardiograms.

Acute Pericarditis is a syndrome generally characterized by chest pain, a pericardial friction rub, and serial ECG changes involving diffuse ST segment elevation and PR depression. It is due to inflammation of the pericardium-the sack surrounding the heart. Often times, the pain is pleuritic-varies with deep inspiration and is affected by body position. When the myocardium (heart muscle) becomes involved, myocarditis results with elevation of the cardiac enzymes. The presenting picture often resembles a heart attack. Patients may run a fever and also complain of shortness of breath.

Common causes of pericarditis include viral or bacterial infections, collagen-vascular or auto-immune diseases (like lupus), kidney failure with uremia, cancer, trauma, as a result of a heart attack or prior chest surgery (post-pericardotomy syndrome), drug reaction, and after radiation therapy. TB used to be a common cause but is not seen frequently in developed countries. Many times, a cause cannot be found and the pericarditis is said to have an 'idiopathic' cause. Pericarditis occurs more commonly in men than women.

The ECG in pericarditis goes through several stages. Initially, the ST segments are elevated with upright T waves. The PR interval may be isoelectric or depressed. As the disease progresses, the elevated ST segments return to baseline and later, the T-waves invert. By recovery, the ST segment, T-waves, and PR intervals return to normal.

Treatment generally consists of observation to make the diagnosis and exclude a heart attack and to watch for the development of Tamponade which can occur in 10-15% of cases. Pain medications are administered and occasionally steroids are required. Most patients recovery normally. Some may go on to have recurrent episodes of symptomatic pericarditis. Tamponade can complicate pericarditis and require pericardiocentesis to drain fluid from around the heart. Late complications include the development of Constrictive Pericarditis.