Improved detection of acute myocardial infarction using a diagnostic algorithm based on calculated epicardial potentials

Background New methods for detecting myocardial infarction in patients with suspected acute coronary syndromes are needed particularly in an era where the majority of patients with myocardial infarction present with non-diagnostic 12-lead electrocardiograms (ECG). We compared a novel epicardial diagnostic algorithm using epicardial potentials from the 80-lead body surface map with other electrocardiographic techniques in detection of myocardial infarction. Methods Between February 1999 and February 2001, consecutive patients (n = 427) with ischemic type chest pain had an initial 12-lead ECG and body surface map recorded. Detecting myocardial infarction using an epicardial algorithm was first performed in a training set (n = 213) and tested in a validation set of patients (n = 214). The results from this epicardial algorithm in myocardial infarction detection were compared with the physicianʹs interpretation of the 12-lead ECG, the body surface map algorithm (PRIME™) and physicianʹs interpretation of the body surface map. Results Myocardial infarction occurred in 205 patients (creatine kinase ≥ 2× upper limit of normal with creatine kinase-MB ≥ 7% CK). The physicianʹs interpretation of the 12-lead ECG identified 122 with myocardial infarction (sensitivity 60%, specificity 99%), the body surface map algorithm 137 (sensitivity 67%, specificity 89%), the physicianʹs interpretation of the body surface map 153 (sensitivity 75%, specificity 91%) and the epicardial algorithm 158 (sensitivity 77% specificity 99%). Combining the physicianʹs interpretation of the 12-lead ECG with the epicardial algorithm increased significantly the detection of myocardial infarction (sensitivity 85%, specificity 98%, p < 0.001) compared with the 12-lead ECG. Conclusions An epicardial algorithm based on epicardial potentials increases significantly the detection of myocardial infarction particularly among those with non-diagnostic 12-lead ECGʹs.