The electrocardiogram in tetralogy of Fallot with complete atrioventricular canal.

The electrocardiograms in nine cases of tetralogy of Fallot with complete atrioventricular canal were reviewed. Only six patients had the typical pattern of right ventricular hypertrophy and superiorly displaced loop in the frontal plane. Of the remaining three patients, two had only right ventricular hypertrophy and one had a normal electrocardiogram. The necessity of two-dimensional echocardiography or an accurate catheterization technique designed to reveal the combined lesions, even when unsuspected, is emphasized.