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Preoperative electrocardiography: its cost-effectiveness in detecting abnormalities when a previous tracing exists.

In 812 patients who underwent routine preoperative electrocardiography a mean of 24.6 months after undergoing electrocardiography at the same institution, the frequency of new abnormalities was estimated to evaluate the cost-effectiveness of this procedure prior to an operation. New abnormalities were judged to be either relevant or irrelevant to the assessment of operative risk, depending upon their previously demonstrated correlation with operative and postoperative morbidity and mortality. Since new abnormalities, especially new relevant abnormalities, were found to be relatively infrequent, the cost-effectiveness of routine preoperative electrocardiography was considered to be low. The evidence suggested that when a previous tracing exists preoperative electrocardiography is most clearly indicated for patients who are 60 years of age or older or whose previous tracing exhibited abnormalities. However, further research is required to develop more sensitive and specific protocols, and to evaluate the role of repeat electrocardiography in clinical decision-making.