Frequency of arrhythmias in acute pericarditis determined by Holter monitoring.

Twenty-four-hour electrocardiographic monitoring in 49 of 50 consecutive patients with acute pericarditis and sinus rhythm at onset (29 with etiologic or unrelated heart disease) disclosed 4 instances of intermittent supraventricular tachycardia, 2 in patients in whom tamponade developed and 1 in a patient with acute myocardial infarction. Eight other arrhythmias, also nonsustained. occurred exclusively in patients with heart disease. Ectopic beats without other arrhythmia occurred in 10 patients without heart disease, but were infrequent (1 to 30 per hour) in 9. Ectopic beats without other arrhythmias occurred in 19 patients with heart disease but were infrequent in 16. Pericarditis per se does not appear to be a recognizable arrhythmogenic influence. As a corollary, significant rhythm disturbance--particularly continuous-beat arrhythmias--during acute pericarditis implies a cardiac abnormality.