Study objective: To determine whether the use of automated serial 12-lead ECG monitoring (SECG) is more sensitive and specific than the initial 12-lead ECG in the detection of injury and ischemia in patients with acute coronary syndromes (ACS) during the initial ED evaluation of patients with chest pain.
Methods: A prospective observational study was performed in 1,000 patients with chest pain who were admitted to a university teaching hospital and who underwent continuous ST-segment monitoring with SECG during the initial ED evaluation. The initial ECG was obtained on presentation, and SECG readings were obtained at least every 20 minutes during the ED evaluation. Diagnostic abnormalities on the initial ECG were defined as injury or ischemia. Diagnostic changes on SECG were defined as evolving injury, evolving ischemia, new injury, or new ischemia. ACS was defined as acute myocardial infarction (AMI), recent myocardial infarction or unstable angina.
Results: A diagnostic SECG was more sensitive than a diagnostic initial ECG for detection of AMI (68.1% versus 55.4%; P < .0001) and ACS (34.2% versus 27.5%; P < .0001). A diagnostic SECG was more specific than a diagnostic initial ECG for detection of ACS (99.4% versus 97.1%; P < .01). SECG detected injury in an additional 16.2% of AMI patients compared with the initial ECG (61.8% versus 45.6%; P < .0001; 95% confidence interval for difference of proportions, 10.9% to 21.4%).
Conclusion: SECG during the initial ED evaluation is more sensitive and more specific than the initial ECG in the identification of ACS. Patients with a diagnostic SECG need intensive antiischemic therapy, evaluation for reperfusion therapy, and admission to an ICU.