SUMMARY

The ECG should be monitored in all patients undergoing anesthesia. Although it does not provide information on the mechanical function of the heart, it permits detection of electrical disturbances that can profoundly affect this function. With the judicious use of selected lead combinations, most arrhythmias and ischemic events can be precisely diagnosed in the intraoperative setting. This diagnostic activity is time consuming, however, and there is considerable evidence that many intraoperative electrocardiographic changes go undetected. There is little doubt that future technologic developments will facilitate the intraoperative recognition of electrocardiographic disturbances and lead to better patient outcomes.