Improved late potential analysis in frequency domain

Computer-enhanced frequency-domain and 12-lead electrocardiography accurately detect abnormalities consistent with obstructive and nonobstructive coronary artery disease

Noninvasive methods of identifying coronary artery disease are not consistently accurate. To identify abnormalities associated with angiographically determined coronary artery disease, the authors sought to quantify 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. The authors compared resting 3DMP results from those of coronary angiograms to identify abnormalities associated with coronary artery disease in a random sample of 136 patients. 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. The system detected abnormalities in 96.0% of patients subsequently found to have 70% or greater stenosis by angiography. For patients with a 40% or less times a more than 50% occlusion, the system detected abnormalities in 75% of cases. For patients with a 50% or less times a 70% or less occlusion, it detected abnormalities in 90% of cases. Overall sensitivity for the study was 93.3% (positive predictive value, 91.2%; specificity, 83%; negative predictive value, 86.7%). No gender differences were detected. A 3DMP electrocardiograph system combined with 12-lead electrocardiography appears to have measurable, diagnostic utility in identifying 3DMP abnormalities associated with coronary artery disease, and warrants further study.