Figure 94-25

ECG from a patient with right ventricular enlargement (volume overload in type ) due to a small atrial septal defect (ostium secundum). Right axis deviation was associated with an incomplete RBBB pattern (rsR' complex in V1).

( Lemberg,L. and others: Vector cardiography,2nd ed. New York, Appleton-Century-Crofts,1975).