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What is A middle aged lady was diagnosed to incidentally have a ejection systolic murmur at the pulmonary area. A fixed wide split of the second heart sound was also noted. The diagnosis is:- and explain in detail?
Classically presents as an asymptomatic patient with a ﬂow murmur in the pulmonary area and a ﬁxed  wide split of S2.
Atrial septal defects occur most commonly in the region of the fossa ovalis, referred to as secundum-type defects .Additional atrial  septal  defects  include  defects  of  the  sinus  venosus  and  atrium primum. Color flow Doppler echocardiography is usually sufficient for diagnosis of a secundum-type atrial septal defect, but agitated saline is generally needed for the diagnosis of other types of atrial septal defects.