<prompt> The presence of left axis detion beyond -30deg in electrocardiogram suggestsFossa ovalis ASDSinus venosus ASDOstium primum ASDCoronary sinus ASD  <response>: The electrocardiogram of ostium secundum ASD is characterized by right axis detion and right ventricular hyperophy. The characteristic configuration of the lead Vl is rsR; seen in almost 90 patients. Presence of left axis detion beyond -30deg suggests ostium primum ASD. Reference: Essential Paediatrics; O.P. Ghai; Page no: 413 