Accuracy of 22-lead ECG analysis for diagnosis of acute myocardial infarction and coronary artery disease in the emergency department: a comparison with 12-lead ECG.

STUDY
OBJECTIVES: To compare a new 22-lead ECG with the 12-lead ECG for diagnosis of acute myocardial infarction (AMI).
DESIGN: Prospective study of all consenting patients presenting to the emergency department with chest pain.
SETTING: Urban hospital ED. TYPE OF PARTICIPANTS: 163 patients admitted with a cardiac-related diagnosis and complete data sets of 22- and 12-lead ECG results and creatine kinase-MB analysis.
INTERVENTIONS: Patient care and existing protocols were unaltered, with the exception of including the new 22-lead ECG.
MEASUREMENTS AND MAIN RESULTS: Forty-one of 163 patients had an AMI as defined by creatine kinase-MB analysis. The 22-lead ECG provided a statistically significant improvement in sensitivity (83%) for AMI diagnosis over the 12-lead ECG (51%) with specificities of 76% and 99%, respectively.
CONCLUSION: When combined with clinical judgment, the 22-lead ECG could provide a 97.6% sensitivity for AMI diagnosis while reducing unnecessary admissions for "rule-out MI" by 69%.