Interpretation of the electrocardiogram: clinical correlation suggested

Abstract

Vijayaraghavan et al. have investigated the interpretation of the initial 12-lead electrocardiogram (ECG) in acute coronary syndrome (ACS) patients, focusing on the patient with potential ST segment elevation myocardial infarction (STEMI).1 The authors emphasize the importance of accurate ECG interpretation by the acute care physician (i.e. emergency physician, internist, and cardiologist).1 The authors compared the initial interpretation of the initial admission ECG by the treating physician with the interpretation of the same tracing by a physician at the core electrocardiographic laboratory. The ECG interpreters at the site were acute care physicians (emergency physician, internist, and cardiologist); at the core lab, the ECG was interpreted by non-cardiologist physicians using specific definitions of abnormality—in this case, ST segment elevation was defined as >0.1 mV in two contiguous leads. The subgroup of patients used in the study were taken from the Canadian ACS Registry and comprised 1310 patients, of which 1202 had complete data and were used for analysis. The definition of STEMI included ST segment elevation and a positive biomarker. What is unclear is whether a positive biomarker was a single spot test or the more appropriate ‘typical rise and fall’ pattern. Overall concordance between core-lab and site interpretation of the admission ECG was 62%. The calculated kappa value was 0.49, indicating modest agreement. When compared with the agreement group of the study, patients in the discordant subgroup were older with higher rates of diabetes mellitus, angina, myocardial infarction, congestive heart failure, coronary artery bypass grafting, and percutaneous coronary intervention. Patients with core-lab-defined ST segment elevation that was not noted by the treating site, who also had a positive biomarker, were significantly less likely to receive aspirin, heparin, and reperfusion therapy when compared with patients with core lab-site ECG interpretation agreement. After adjusting for other validated prognostic factors, site-unrecognized ST … *Corresponding author: Tel: +1 4344651816, Fax: +1 4349242877. Email: wb4z{at}hscmail.mcc.virginia.edu