Ecg Interpretation for the Emergency Department

Accepted 29 April 1999 Patients presenting to the accident and emergency department with chest pain of potentially ischaemic origin are evaluated with three principle tools: the history of the event, the 12 lead electrocardiogram (ECG), and, in suspected cases of acute myocardial infarction (AMI), serum markers of cardiac injury. An accurate clinical history is pivotal in the evaluation of such patients and is a prerequisite for the correct interpretation of the ECG. The ECG is an important adjunct in the evaluation of patients with chest pain and assists the doctor in the selection of the correct management for the individual-in particular the application of treatment aimed at coronary reperfusion. Although serial ECGs are sensitive for the diagnosis of AMI, a single ECG is frequently much less helpful. In those patients who present with a clinical history compatible with AMI, fewer than 50% of patients will have the diagnostic changes of AMI on the initial ECG. The remainder will have either obvious ischaemic changes, non-specific ST segment/T wave abnormalities, or an entirely normal ECG.' The uninformed clinician may be tempted to inappropriately discharge patients with acute chest pain if the ECG is normal or reveals only minor non-diagnostic changes.