Dental patient reaction to electrocardiogram screening. Ninety-one patients receiving routine dental treatment at the University of Minnesota School of Dentistry participated in an electrocardiogram screening study. The purpose of the study was to evaluate patient reaction to electrocardiogram screening in a dental school clinic. The vast majority of patients indicated the test was easy and did not intrude on the dental appointment. Most of the patients reported that the test was a valuable service and should be available in the dental office. None of the patients indicated that the tests should not be performed in the dental office. Few patients expressed any significant concern or anxiety about the test either before or after it was completed. Twenty-six percent (24/91) of the patients were found to have a cardiac arrhythmia; however, most of these were nonserious arrhythmias (18/24) and would not have had an impact on planned dental procedures. Six patients were identified with arrhythmias that required medical referral before dental treatment was started. 