Studies on Vectorcardiogram

Part I Vectorcardiographic Patterns of Normal Young People by Means of Frank Method and Kimura Method

Abstract

Quantitative analysis of the vectorcardiography on 172 normal young people, using the Frank method. The following results were obtained.
1) The QRS spatial maximum vector magunitude and QRS-T angle revealed 1.63±0.42mV and 27.3±15.1°, respectively. These values were somewhat small and remained in narrow distribution as compared to other reports. The T spatial maximum vector magnitude was 0.59±0.11mV. This value was almost same as that of the others.
2) The QRS long axis in horizontal plane was -29.5±25.6° and oriented backward as compared to other reports. This results the variety of the type of QRS vector loop in horizontal plane in this age group.
3) The QRS half area axis was distributed in narrow range of -11.4±20.8°. Therefore, the wide angle was found between this axis and QRS long axis. This shows the validity of the concept of half area vector.
4) The QRS vector was classified into 6 types in our laboratory, and found the order of incidence to be d, c, and f.
5) The ratio of the T and QRS spatial maximum vector has the tendency to become smaller with aging, on the contrary, the spatial maximum QRS-T angle become wider with aging.
6) In this study, any vectorcardiographic change between both sexes could not be found.
7) Comparing Frank method with Kimura method, it was found that the spatial maximum QRS-T angle showed the wide range of distribution of 26.1±20.6° in Kimura method and the Y component has the tendency to be augmented, on the contrary, X and Z components were liable to be reduced. These results indicated that the Kimura method has larger distribution.