Abstract
Nine cases of Fallot' Tetralogy were studied by Frank system VCG and the following results were obtained.
QRS maximum vectors were inscribed to left inferiorly in the four cases of nine and to right and anteriorly in the five cases of nine.
T maximum vectors were inscribed to left inferiorly and posteriorly in most of the cases.
Initial portions of QRS loops were inscribed to left and anteriorly in all of the cases and the terminal portions to right anteriorly in most of the cases.
QRS loops were inscribed in most of the cases in a clockwise direction in frontal plane, in three cases in a clokwise direction, in four cases in a counterclockwise direction, and in two cases in a figure-of-eight pattern in right sagittal plane.
In horizontal plane only three cases were inscribed counterclockwise, two cases in a figure-of-eight pattern and four cases clockwise.
T loops were inscribed clockwise in all of the cases in frontal plane, counterclockwise in seven cases in right sagittal plane and clockwise in seven cases in horizontal plane.
These changes of the rotation of T loops were based on the right ventricular hypertrophy.
Vectorcardiographically five cases were diagnosed as right ventricular hypertrophy, two cases as changing pattern to right venticular hypertrophy, one case as right bundle branch block and one case as normal.
T loops were discordant to QRS loops in the three cases of five which were diagnosed as right ventricular hypertrophy.
In horizontal plane QRS/T ratios were over five in four cases of which the arterial oxygen saturation was under sixty percent.
QRS maximum vectors were inscribed in right horizontal position in frontal plane in the cases of which right ventricular oxygen saturation was under sixty percent.
Three vectorcardiograms of Fallot' Tetralogy were represented.
