Abstract
Purpose: In Japan, the electrocardiogram (ECG) in emergency hospital transport is usually performed using three electrodes. However, as compared to the conventional 12-lead ECG, the three-electrode ECG is considered to be inferior for the diagnosis and monitoring of ischemic heart disease. In this paper, we evaluated the usefulness of a synthesized 12-lead ECG (Syn-ECG) constructed from four of the standard 12 leads, to investigate whether the diagnostic capability of this system would be comparable to that of the standard 12-lead ECG (Stn-ECG). Methods: Twelve-lead ECGs were synthesized in 54 patients (38 males, 16 females; average age, 68 years) with abnormal Q waves and ST-segment changes in the Stn-ECG. Leads I, II, V2 and V4 were used to synthesize the other leads. The Q wave, R wave and S wave amplitudes and the ST-segment and T wave changes in the Stn-ECG were compared to those in the Syn-ECG by calculating Spearman's correlation coefficient. Results: Significant equilateral correlations were found among the Q wave, R wave and S wave amplitudes and in the ST-segment (including the magnitude of elevation and depression) and T wave changes in the two lead systems. The characteristics of the waveforms were similar in the two types of ECG's, but the voltage levels of the waves in the Syn-ECG were slightly different from those in the Stn-ECG. Conclusion: We concluded that the Syn-ECG can yield sufficient precision for the diagnosis and monitoring of ischemic heart disease, and that it can contribute to improved pre-hospital diagnostic evaluation of cases of ischemic heart disease.
