Quantitation of ventricular hypertrophy and hemodynamic load with vectrocardiogram

Studies in 540 children with congenital heart disease have shown correlations between the orthogonal electrocardiogram and the hemodynamic load placed on the right and left ventricles. Using the Frank lead system, the maximum spatial voltage directed to the left has been shown to reflect the degree of pressure or volume overload of the left ventricle in patients with aortic stenosis and septal defects and even in the cyanotic lesions tetralogy of Fallot and complete transposition of the great arteries. The maximum spatial voltage directed to the right has been found to correlate well with pressure overload of the right ventricle in patients with pulmonic stenosis and septal defects. The direction of rotation of the vectorcardiographic loop in the horizontal plane has been shown to reflect well the relative hemodynamic loads on the two ventricles, and thus presumably the relative degrees of left and right ventricular hypertrophy present. In certain lesions, the electrocardiographic-hemodynamic correlations are close enough to allow the Frank electrocardiogram to be of significant help in the clinical management of children with congenital heart disease.