Frank法ベクトル心電図のI, E, C, A, M電極の位置の検討(Three step technic, Y-Precordial technicによる) 第1編 胴体模型による基礎的検討

Although it has been considered that the transverse level of chest electrodes (I, E, C, A, M) is important to the accuracy of the dipole component derived from the lead system of vectorcardiography, there are few papers available which deal with this problem. Using a Japanese male torso model with a homogeneous volume conductor, the following two points were investigated: 1) indication of the correct level of artificial dipole with a three step technic and a Y-Precordial technic, 2) effects of shift in the level of the dipole and of chest electrodes from the fifth to the third, fourth or sixth intercostal space on the lead vector. The following results were obtained: 1) The three step and Y-Precordial technics indicated the correct level of artificial dipole. 2) The magnitude of lead vector Z and the elevation of lead vector X and Z were changed markedly by moving chest electrodes upward or downward from the artificial dipole level. A concomitant shift of the chest electrodes with the dipole, however, caused trivial changes in the components of the lead vector, regardless of the level moved upward or downward from the fifth intercostal space The results indicate that in the homogeneous torso model, chest electrodes should be present at the same level as the dipole, which can be detected by the three step and Y-Precordial technics.