A 45 year-old lady has 10 months history of shortness of breath. She is found to have irregularly irregular pulse and loud P2 with fixed splitting and ejection systolic murmur in left 2nd ICS. What is the probable diagnosis?

The key is B. Atrial septal defect. [Most adult patients with a large defect present with (some or all)

symptoms including fatigue, exercise intolerance, palpitations, syncope, shortness of breath, peripheral

oedema, thromboembolic manifestations, and cyanosis. Arrhythmias are more common after 40 years

of age. The common arrhythmias are atrial flutter and atrial fibrillation. Auscultatory findings are:

• Loud P2 with fixed splitting of 2nd heart sound. A left-to-right shunt caused increased loading on

the right ventricle, leading to delayed emptying and therefore delayed closure of the pulmonary

valve which caused this splitting.

• Soft systolic ejection murmur in the pulmonary area at the upper left sternal border.

• A diastolic rumble over the left lower sternum because of increased flow through the tricuspid

valve.

Classic auscultatory findings as described above are not present unless the shunt is reasonably large.