Background: There is no consistently accurate noninvasive tests for identifying coronary artery disease. This study is designed to confirm the utility of a new device, a digital database-driven multiphase electrocardiograph system (3DMP), which produces a computer-enhanced frequency/time-domain resting electrocardiogram, in conjunction with a 12-lead electrocardiogram. Methods: We analyzed the 3DMP system's sensitivity and specificity in the identification of CAD ischemia with or without other coexisting pathologies with a coronary angiogram. Patients who have native coronary artery disease were randomly selected from a patient cohort that has been clinically designated for diagnostic coronary angiography. The 3DMP EKG System results and the angiography results were sent to the Data Monitor for double-blind data analysis and interpretation. The sample size was 100 patients, with tracings of sufficient quality for interpretation. Using a discrete-Fourier transform signal-averaging variant and a series of mathematic transformations, the computer-expert system analyzed signals in the 0.1- to 50-Hz range. The system identified abnormalities by comparing results with a 21,000-patient database culled from predicate research. Results: The system detected abnormalities in 97% of patients subsequently found to have 75% or greater stenosis by angiography. Overall sensitivity for the study was 95% (positive predictive value, 93%; specificity, 80%; negative predictive value, 86%). No gender differences were detected. Conclusion: A 3DMP electrocardiograph system might to be a auxiliary diagnostic test of identifying coronary artery disease combining with 12-lead electrocardiography, especially for the primary care physicians, and warrants more large-scaled clinical study.