Agreement between actual and synthesized right-sided and posterior electrocardiographic leads in identifying ischemia

Objective: A 12-lead electrocardiogram (ECG) is the standard of care for chest pain patients. However, 12-lead ECGs have difficulty detecting ischemia of the right ventricle or posterior wall of the heart. New technology exists to mathematically synthesize these leads from a 12-lead ECG; however, this technology has not been evaluated in the emergency department (ED). We assessed the level of agreement between synthesized 18-lead ECGs and actual 18-lead ECGs in identifying ST elevations, ST depressions, and T wave inversions in ED patients. Methods: Actual 12- and 18-lead ECGs were acquired and synthesized 18-lead ECGs were produced based on waveforms from 12-lead ECGs. A blinded cardiologist interpreted the actual and synthesized 18-lead ECGs to identify the presence of abnormalities. Using actual 18-lead ECGs as the reference, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and kappa of synthesized 18-lead ECGs in identifying abnormalities were determined. Results: Data from 295 patients were analyzed. There was 100% agreement between synthesized 18-lead ECGs and actual 18-lead ECGs in identifying ST elevations and ST depressions (sensitivity, specificity, PPV, and NPV of 100%, and kappa of 1.00). Synthesized 18-lead ECGs had 95% sensitivity, 80% specificity, 97% PPV, and 70% NPV in identifying T wave inversions, when compared with actual 18-lead ECGs (kappa: 0.70). Conclusion: Synthesized 18-lead ECGs demonstrated 100% agreement with actual 18-lead ECGs in the identification of ST elevations and ST depressions and good agreement in the identification of T wave inversions in a sample of patients ED patients with complaints suspicious of cardiac origin.