A nonlinear regression model as applied to the comparison of axis-angles of electrocardiographic systems.
The systematic nonlinearity exhibited in a comparison of 2 commonly used electrocardiographic lead-systems, when the net QRS axis-angle from one system is plotted against the other, is quantitatively analyzed. A family of nonlinear correlation curves is implemented using the ratio of 2 correction factors, fc/fo, as a parameter. Such curves, replacing linear regression lines, provide a more realistic representation of the actual problem of this type. Between the Frank and the 12-lead systems, the value of fc/fo is found to be 0.53 for the frontal plane from a sample of 1,000 subjects. The combination of correction factors, fc=1.155 and fo=2.18, is a possibility among countless others to make up the same fc/fo of 0.53. Appreciable improvement in axis correlation is demonstrated after the data are corrected by such factors.
D004562:Electrocardiography / Q000379:methods*; D008962:Models, Theoretical; D012044:Regression Analysis; D014672:Vectorcardiography / Q000379:methods