The electrocardiogram in congenital heart disease; with special reference to left axis deviation.

The incidence of the four main types of axis deviation in each diagnostic group of congenital malformations of the heart was found by an examination of 2,752 electrocardiograms from the Harriet Lane Home Cardiac Clinic. Records from patients with dextrocardia or dextrarotation of the heart, and those with complete bundle branch block were excluded. The precordial and unipolar limb leads in the 289 electrocardiograms which showed left axis deviation were examined, and the types of precordial pattern most frequently seen in the different diagnostic groups analyzed. It is concluded that the precordial patterns show considerable difference in the various malformations associated with left axis deviation, and are of diagnostic aid.