Computer-assisted electrocardiography in structured diagnosis of acute myocardial infarction

The purpose of this study was to investigate the applicability of computerized electrocardiogram interpretation in classifying patients with suspected acute myocardial infarction. Computerized acquisition and analysis of the 12-lead electrocardiogram can increase the consistency and reduce the workload of patient classification. The serial electrocardiograms of 311 consecutive patients with suspected myocardial infarction were studied and a new computerized myocardial infarction (CMI) electrocardiographic classification was developed and compared with one commercially available and two manual codes. Statistically, there was almost no correlation between the four ECG codes. Compared with the WHO enzymatic criteria, the sensitivity of the CMI code toward detecting definite and possible infarction was 69.2% and 29.8% with a specificity of 62.1% and 79.7%, respectively. In subjects without previous infarction (n = 214) the sensitivity of the CMI code for definite enzymatic infarction was 71.9% and specificity 77.6%. Substituting the CMI for the Minnesota code had no effect on patient classification by the WHO MONICA criteria in 78% of patients with first infarction. Judged by cardiac macromolecular leakage, all electrocardiographic classifications of possible infarction were poorly correlated with myocardial tissue injury. We have developed a new computerized coding system to detect electrocardiographic myocardial infarction. The structure of the code allows interactive redefinition of criteria to meet user-defined needs. However, because of the weak relationship between electrocardiographic and biochemical criteria of myocardial injury, the role of ECG in the diagnostic classification of acute ischemic syndromes should be re-evaluated.