Quantitation of the normal Frank and McFee-Parungao orthogonal electrocardiogram in the adolescent.

A detailed linear, circular and spherical quantitation of the Frank and McFee-Parungao orthogonal electrocardiograms of 166 adolescents is presented. There are significant differences between pubescent males and females: (1) QRS and T magnitudes in the male are greater than in the female. (2) The difference in magnitudes is greater at age 11-15 than at age 16-19, presumably because females reach puberty earlier. (3) The differences in magnitudes are on the X and Z axes but not the Y axis. (4) Males achieve their maximal posterior QRS orientation sooner than females and are more superior as it occurs. (5) The female's T vector is less anterior than the male's. (6) The angular deviation of T from QRS is less in females than males for the horizontal and sagittal planes. There are significant differences between the two lead systems: (1) The McFee-Parungao's voltages are greater than those of the Frank system. (2) On the X axis, the Frank leftward vector is 62% of the McFee, but the terminal rightward vector is 85% of the McFee. (3) On the Y axis, the Frank inferior vector is 76% of the McFee, but initial superior is 90% and the terminal superior 62% of the McFee. (4) On the X axis, 25% is terminally to the right in the Frank, but only 15% in the McFee. (5) The Frank system is oriented slightly more posterior than the MeFee, though the T vectors are not oriented differently. There is no evidence that the spatial QRS and T orientations are related to each other.