Similarities and discrepances between derived vector electrocardiogram parameters in McFee—Parungao vs Frank lead systems

Objective. To determine vECG and orthogonal ECG3 parameters and ranges of their changes for which diagnostic significance of estimates will be the same between MacPhee-Parungao leads calculated using Trunov-Aidu transformation and most common Frank leads calculated using Kors matrix and inverse Dauer matrix. Material and methods. An observational single-center non-controlled study included 1250 digital 12-lead ECGs recorded from 1250 adults with common cardiovascular diseases: hypertension, coronary artery disease, previous myocardial infarction, aortic stenosis, etc. We calculated orthogonal ECG3 in McFee-Parungao (Trunov-Aidu matrix) and Frank (Kors matrix and Dawer inverse matrix) leads. Statistical processing included correlation analysis and Bland-Altman plots to assess measurement agreement. Results. The study found significant diversity in ECG patterns among all ECGs. Amplitudes of ECG3 waves showed good agreement across all transformations. Integral vectors, fractional integrals, and ventricular gradient demonstrated high correlation. While spatial area of QRS loop showed consistency, its projections on orthogonal planes were less aligned. Spatial angle QRS-T exhibited high degree of linear correlation. Planar indexes of QRS loop and length parameters showed close results between McFee-Parungao and Frank systems. Conclusion. Measurements of integral vECG characteristics in computational orthogonal lead systems McFee-Parungao and Frank yield comparable results. Extreme values of spatial angle QRS-T (>130°) associated with high cardiovascular risk show high agreement. However, intermediate and borderline values should be interpreted considering calculation method. Planar indexes>0.91 may also be interpreted with high consistency.