26th April 2024

A 9-year-old boy presents with a 6-month history of increasing breathlessness, particularly on exertion, and a persistent cough.

A 9-year-old boy presents with a 6-month history of increasing breathlessness, particularly on exertion, and a persistent cough. Recently, he has started experiencing swelling in his ankles. His medical history is unremarkable, and there is no family history of cardiac diseases. On examination, jugular venous distension is noted. Auscultation reveals a holosystolic murmur at the left lower sternal border that intensifies on inspiration.

Which is the most likely diagnosis?