[Electrical position of the heart and its variants in a new electrocardiographic system with 9 bipolar leads].

Consideration given to the position type of the traditional ECG, the changes in the amplitudes of R, S and T were discussed in the system with 9 bipolar leads (A-I), grouped according to age and sex in 151 healthy subjects with the leads on the back (H and I) the alteration and Q deflection were assessed. The results in each position type are compared with those of the whole group with the respective age and sex. In the first age group (20-29) the vertical position showed alteration only among the females (increase of SA and reduction of RHI), whereas the indifferent position--only among the males (increase of RF and reduction of SHI). In the second age group (30-44) the vertical position showed an increase of the amplitude of SCE among the males, whereas among the females--RH and QHI were reduced, but SHI increased; the indifferent position showed changes only among the females (increased RD) whereas the horizontal (only females) showed a reduction of SABCHI. In the third age group (45-60) the indifferent position showed changes only among the females (increased amplitudes of SA and QHI); the horizontal position among the males showed an increase of RB, and among the females--increased of QH and reduction of SBHI. The negative T-deflections are mainly found among the younger subjects, in the first leads in front (A-C), and more often--among the females. The possibilities for differentiation of the altered Q deflection in the leads H and I are discussed, with a view to acute or healed inferior-diaphragmatic myocardial infarction.