[Electro-vectorcardiographic examination in cardiopathy of pulmonary origin].

We describe the electrical signs due to the positional changes of the heart and those related to hypertrophy and dilatation of the right heart chambers in subjects with chronic cor pulmonale. The positional changes mainly reflect the vertical position of the heart, which is almost constantly associated with some degree of clockwise rotation, because of the descent of the diaphragm and increase of lung volume owing to chronic emphysema. The electrovectorcardiographic alterations observed in right ventricular hypertrophy owing to permanent pulmonary arterial hypertension differ depending on the type of hypertrophy: global or segmentary. The first is generally observed in the chronic hypertensive pulmonary cardiopathy of vascular origin and produces an increase in the magnitude and manifestation of all the principal vectors of right ventricular activation. The second is frequently present in the chronic hypertensive pulmonary cardiopathy of bronchial origin and increases only the magnitude and manifestation of the right basal vector. The progressive dilatation of the right heart chambers evident during the evolution of the chronic hypertensive pulmonary cardiopathy toward the congestive heart failure produces SAQRS rotation to the right, downward and forward or backward. During acute intercurrent bronchopulmonary infection or embolia, transient electrical signs of right cardiac chambers dilatation are present.