右脚ブロック及び不完全右脚ブロックのベクトル心電図学的分析 : 並びに僧帽瓣膜疾患時rSR'-V<SUB>1</SUB> patternとの比較検討

1) A study is made of the VCG patterns using Grishman's and Kimura's cube system of 48 cases with complete right bundle branch block (RBBB) and 32 cases with incomplete RBBB, in comparison with 17 cases of mitral valvular disease showing rSR'-V₁ pattern (QRS duration <0.11 second) in the ECG (Table I). Relations between the configuration of the QRS loop and the subtype of RBBB in the ECG or the underlying disease, and those between the configuration of the T loop or S-T vector and the ventricular gradient are analysed.2) There is a certain relationship between the orientation of the QRS loop in the VCG and the subtype (following the classification by Bayley, Pardee, and Lepeschkin) of RBBB in the ECG in the frontal plane. In the present study, the aforementioned criteria of the classification is applied also for incomplete RBBB. Eight cases which resemble Subtype IVa, but having narrow S_III, are classified tentatively as Subtype IVa' (Fig. 1).The main part of the QRS loop of Grishman vector is mostly oriented to the right and inferiorly or to the left and inferiorly in Subtype I, to the left and inferiorly in Subtype II, III, IVa and IVa', and to the left and superiorly in Subtype IVb, Va and Vb, and that of Kimura vector is mostly oriented to the right and inferiorly or to the left and inferiorly in Subtype I and II, to the left and inferiorly or to the left and superiorly in Subtype III, to the left and inferiorly in Subtype IVa, IVa', IVb, and extended superiorly and inferiorly in Subtype Va and Vb.The terminal appendage of Grishman vector is mostly oriented to the right and superiorly or to the right and inferiorly in Subtype I and II, and to the right and superiorly in the other subtypes. The terminal appendage or terminal portion of Kimura vector is mostly oriented to the right and superiorly or to the right and inferiorly in Subtype I and III, to the right and inferiorly in Subtype II, and to the right and superiorly in the other subtypes. But the direction of inscription or the configuration of the QRS loop in the frontal and horizontal planes in each case is closely related to the underlying disease, and is different although these cases are classified into the same subtype.3) Group L.-In this group, 30 cases with hypertension or with left ventricular enlargement on the x-ray are included. The main part of the QRS loop of Grishman vector (Table III) is mostly inscribed in a counterclockwise direction in the frontal plane and in the horizontal plane, and the terminal appendage is mostly inscribed in a counterclockwise direction in the horizontal plane (Fig. 4, 6, 7). The main part of the QRS loop of Kimura vector (Table V) is mostly in a counterclockwise direction in the frontal plane (Fig. 17, 19, 21, 22).Appedix : In five cases with myocardial infarction and RBBB, the initial portion and the main part of the QRS loop of Grishman vector are displaced to the opposite direction of the infarcted area, and the main part of the QRS loop is mostly inscribed in a counterclockwise direction in the frontal plane (Fig. 8, 9). The configuration of the QRS loop of myocardial infarction of Kimura vector showing nearly the same configuration as that of Grishman vector. But in the cases with anterior infarction, the initial portion of the QRS loop of Kimura vector is sharply displaced to the opposite direction of the infarcted area (Fig. 23, 24).