The Electrocardiogram, Vectorcardiogram, and Ventricular Gradient in the Tetralogy of Fallot

Corrected transposition of the great vessels: a vectorcardiographic study

The vectorcardiograms (VCGs) of two groups of patients with corrected transposition of the great vessels (CTGV) were studied; the first, group A, included 17 patients with CTGV in "situs solitus,", characterized by leftward orientation of the cardiac apex; the second group, group B, with three patients, presented CTGV in "situs solitus" and apex to the right. All cases had one or more associated defects: ventricular septal defect, atrial septal defect, pulmonic stenosis or tricuspid insufficiency.

Vectocardiography in tetralogy of Fallot before and after operation (palliative and corrective surgery)

Vectorcardiograms from 55 patients with diagnosed tetralogy of Fallot were studied and divided into the following three groups: A, 35 nonoperated cases; B, 23 with systemic-pulmonary shunt (nine studied preoperatively and also in A); and C, ten after total correction. In group A, two different types of QRS loop occurred in the horizontal plane (HP); 23 clinically and hemodynamically severe cases had right anterior position with clockwise (C) rotation, and 12 less severe cases had right posterior position with counterclockwise (CC) rotation or figure-8 morphology. In the frontal plane the QRS loop was located inferiorly and to the right, with C rotation (80 percent); two cases had the left anterior hemiblock (LAHB) pattern, and another two severe cases had CC rotation and right superior position. Group B had an evident increase of left ventricular forces in the HP, compared with group A; group-B rotation was preferentially CC or figure-8 morphology. Group C had a pattern of right bundle-branch block in nine cases (classic in one and uncharacteristic in eight); four cases also had LAHB.