Complete Transposition of the Great Vessels
II. An Electrocardiographic Analysis
A correlative study of necropsy findings and electrocardiography in 54 cases of complete transposition of the great vessels was made to determine whether or not specific electrical patterns could predict the status of the ventricular septum. It became apparent that published criteria for distinguishing between patients with a ventricular septal defect and those with an intact ventricular septum were not uniformly reliable.
Rather than the location of a communication, the important factor in differentiation depended upon the size of the opening, be it between the ventricles or through a patent ductus arteriosus.
Cases were divided into two groups: In group I were those with a small communication, and in group II were those with a large communication between the greater and lesser circulations. The group with small communication showed a narrow or obliterated ductus arteriosus and an intact ventricular septum, or a small ventricular septal defect. In group II there was either a wide patent ductus arteriosus with an intact ventricular septum or a large ventricular septal defect.
In group I the electrocardiogram predominantly showed isolated right ventricular hypertrophy, whereas, in group II, biventricular hypertrophy was the usual finding.
Among the five patients in whom the mean manifest electrical axis was deviated to the left, two showed obstructive malformations of the aortic arch, and two left ventricular-right atrial communication. The fifth case was simply one of a large communication without complicating anomalies.
- © 1963 American Heart Association, Inc.