Country cardiograms: Case 1
The electrocardiogram (ECG) showed normal 1 mV/cm Y-axis standardization and normal sinus rhythm. There is a nonspecific rSRī complex in lead V1. The abnormal findings are widespread nonspecific ST depression in many leads, PR depression in lead II and perhaps some precordial leads, and PR elevation in the aVR lead. These findings suggest pericarditis. The classical early findings of acute pericarditis are widespread ST elevation and the PR changes that were seen in this patient's ECG. The ECG generally shows more localized ST elevation in ischemia secondary to coronary artery disease. In this patient the ST segments are depressed, but atypical ECG findings are not uncommon in pericarditis.
On requestioning, it became clear that the patient's pain was typical of pericarditis: she noticed that the pain was worse with respiratory movements, with every heartbeat and when she was supine, and that it was relieved by sitting forward. She became certain that the pain had been constant for at least 24 hours, without going away at all during that time. The important differential diagnosis was myocardial ischemia.
Discussion
Uncomplicated pericarditis can be treated locally in most rural settings, but geography was an important factor in this case. The patient lived a long way from our hospital, the winter weather was poor, and local ambulance service was intermittent. We were concerned about the development of complications, such as cardiac tamponade or arrhythmia, and we were still concerned about the possibility of ischemia. We decided to admit her to our hospital. We sent the ECG by fax to an on-call urban cardiologist at his home during a telephone consultation. He agreed with the diagnosis and our plans for management. He also agreed that the most likely cause was viral illness.
Although the risk of complications appears to be low in viral pericarditis, we needed more precise estimates to aid our decision about whether to discharge the patient home, admit her to our rural hospital for observation or transfer her elsewhere. We used Grateful Med to perform a computer search of the medical literature in Medline. We found no studies of acute pericarditis in rural settings and little information that would help us to predict the risk that complications might develop over subsequent days. We therefore decided to admit the patient to our hospital for observation, pain relief, serial electrocardiography and serial testing of cardiac enzymes.
We used our clinic computer to search for further information about the patient's management. We found help on the Internet at the Web site called "Topics in Primary Care" (http://uhs.bsd.uchicago.edu/uhs/topics/acutepericarditis.html), which is maintained by the University of Chicago. The advice we found there gave us further confidence in our course of action by supporting our diagnosis and reaffirming our management options. The Scientific American Medicine CD-ROM (SAM-CD)1 provided a more detailed pathophysiological discussion. Neither source gave precise estimates of the risks of serious complications.
Patients with viral pericarditis usually need only symptomatic therapy to control pain. If simple measures fail, one option is to give indomethacin (50 mg four times daily, tapered over 4 weeks to about 25 mg daily).
If nonsteroidal anti-inflammatory drug therapy is contraindicated or not tolerated, then another option is to give prednisone at 20 to 60 mg/day, tapered over 2 to 4 weeks. Because this patient had significant ulcer and gastroesophageal reflux disease, we treated her pain with narcotic medication and observed her.
Over the next few days the patient's ECG normalized, the pain diminished, and there was no evidence of myocardial injury in cardiac enzyme studies. She was discharged home for weekly follow-up in our family practice clinic over the next month. The pain resolved fully in 2 weeks. The ECG returned to normal without the T-wave inversions often seen in pericarditis, suggesting that this may have been a mild case. We elected not to send the patient to the city for echocardiography to look for effusion, because the clinical history and exam showed no sign of tamponade. The patient was warned about the moderate risk of recurrence.
Reference
1. Scientific American Medicine [CD-ROM], Online Computer Systems, June 1995