Right Axis Deviation, Clockwise QRS Loop, and Signs of Left Ventricular Underdevelopment in a Child with Complete Type of Persistent Common Atrioventricular Canal

Abstract

Clinical data and findings at necropsy are presented on a 2-year-old girl who had persistent complete common atrioventricular canal, hypoplastic left ventricle, and obstruction to the left ventricular outflow tract. Electro-cardiographic findings were atypical of common atrioventricular canal in that right axis deviation and a clockwise inscription of the QRS loop in the frontal plane were present. Findings in this case suggest that under-development of the left ventricle should be suspected when (1) displacement of the interventricular sulcus is noted on roentgenographic examinations and (2) predominant left-to-right shunting at ventricular level is found in the absence of electrocardiographic evidence of left ventricular overload.