Current Electrocardiogram Research Articles

Usefulness of serial electrocardiograms for diagnosis of acute myocardial infarction

The purpose of this study was to determine whether the automated detection of acute myocardial infarction (AMI) by utilizing artificial neural networks was improved by using a previous electrocardiogram (ECG) in addition to the current ECG. A total of 4,691 ECGs were recorded from patients admitted to an emergency department due to suspected AMI. Of these, 902 ECGs, in which diagnoses of AMI were later confirmed, formed the study group, whereas the remaining 3,789 ECGS comprised the control group. For each ECG recorded, a previous ECG of the same patient was selected from the clinical electrocardiographic database. Artificial neural networks were then programed to detect AMI based on either the current ECG only or on the combination of the previous and the current ECGs. On this basis, 3 assessors—a neural network, an experienced cardiologist, and an intern—separately classified the ECGs of the test group, with and without access to the previous ECG. The detection performance, as measured by the area under the receiver operating characteristic curve, showed an increase for all assessors with access to previous ECGs. The neural network improved from 0.85 to 0.88 (p = 0.02), the cardiologist from 0.79 to 0.81 (p = 0.36), and the intern from 0.71 to 0.78 (p <0.001). Thus, the performance of a neural network, detecting AMI in an ECG, is improved when a previous ECG is used as an additional input.

Impact of the availability of a prior electrocardiogram on the triage of the patient with acute chest pain

To determine whether information from a prior electrocardiogram (ECG) improves diagnostic accuracy in the emergency department (ED) evaluation of patients with acute chest pain. Analysis of prospectively collected data from a cohort study. Emergency departments of four community and three university hospitals. 5,673 patients aged greater than or equal to 30 years who presented to the EDs of participating hospitals for evaluation of acute chest pain, including 772 (14%) with acute myocardial infarction (AMI). After adjusting for clinical characteristics, no significant difference was found in the sensitivities of admission to the hospital or to the coronary care unit (CCU) between AMI patients with and without prior ECGs available for review. However, non-AMI patients with prior ECGs available for review were more likely to avoid CCU admission than were non-AMI patients without prior ECGs. This improvement in specificity was most marked in the 2,024 patients whose current ED ECGs had changes consistent with ischemia or infarction: when a prior ECG was available, non-AMI patients were more than twice as likely to be discharged (26% vs. 12%) and about 1.5 times as likely to avoid CCU admission (39% vs. 27%) (both p less than 0.0001). Admission rates of AMI patients with and without prior ECGs were similar. When the current ECG is consistent with ischemia or infarction, the availability of a prior ECG for comparison to determine whether the ECG changes are old or new improves diagnostic accuracy and triage decisions by reducing the admission of patients without AMI or acute ischemic heart disease (increased specificity) without reducing the admission of patients with these diagnoses (unchanged sensitivity).