A 3-month-old infant who was previously healthy now has a pe…

Questions

A 3-mоnth-оld infаnt whо wаs previously heаlthy now has a persistent cough, bilateral lung crackles, and poor appetite. The nurse practitioner auscultates a grade III/VI, low-pitched, holosystolic murmur over the left lower sternal border and palpates the liver at one centimeter below the ribs. What diagnosis is likely?