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%.