The electrocardiogram in congenital heart disease; a preliminary report.

Adequate unipolar electrocardiograms have been recorded on 101 patients with congenital heart disease and the findings analyzed. It has been found that the chief value of such tracings rests in the determination of ventricular preponderance, the evidence being obtained from study of the QRS complexes in unipolar limb and multiple precordial leads, with relatively little help from the RS-T segments and T waves. Auricular hypertrophy, encountered chiefly in association with pulmonic stenosis and tricuspid valve disease, could be best detected by analysis of P waves seen in the right precordial leads rather than in the limb leads. Intraventricular block was observed both with auricular and with ventricular septal defects, and was also found in Ebstein's disease and with coarctation of the aorta. Auriculoventricular block and arrhythmias were rare. A CCURATE diagnosis of congenital cardiac lesions no longer must await evidence supplied at the autopsy table. Today, in the majority of such cases, specific and precise data as to the nature of single or multiple cardiovascular anomalies can be obtained as the result of a careful assessment of clinical and laboratory findings. It is well known that the history and physical examination by themselves are often inadequate to provide a satisfactory diagnosis; and information secured through roentgenologic study, including angiocardiography, and cardiac cath-eterization, including blood gas analysis, are necessary in many instances. The electrocardio-gram is an additional and valuable laboratory tool. It does not by itself provide a final answer, except in instances of uncomplicated dextro-cardia of the situs inversus type, but it does indicate whether gross preponderance and hypertrophy of the right or left ventricles exist, whether there is evidence of auricular hypertrophy, and whether abnormalities of rhythm or conduction are present. The analysis of electrocardiographic tracings 564 in the congenital cardiac group is not altogether easy. In order to obtain maximum help in determining the presence of an abnormal right or left ventricular preponderance, at least three and preferably more precordial leads should be available; in this regard, the uni-polar limb leads are of value as a guide to the electrical position of the heart. Furthermore, while it is not difficult to detect abnormally high voltage of the QRS complexes in adults, it is a different matter in infants and young children, where the thinness of the chest wall and proportions of the heart and thoracic cage are such that relatively high voltage complexes may normally be found. Reliable …