Review Question - QID 211025

A 17-year-old boy is brought to the pediatrician by his mother for an initial visit. He recently immigrated from Cambodia. The patient reports 6 months of mild exertional dyspnea. He denies chest pain or palpitations. His medical history is unremarkable and he has never had any surgeries. His family history is significant for hypertension and diabetes. His father died of tuberculosis. The patient’s vaccination history is unknown. His temperature is 98°F (36.7°C), blood pressure is 113/71 mmHg, pulse is 82/min, respirations are 12/min, and oxygen saturation is 98% on room air. His BMI is 24 kg/m^2. Physical examination shows a well-nourished, cooperative boy without any grossly dysmorphic features. Cardiac auscultation reveals a grade 2 systolic ejection murmur along the left upper sternal border and a mid-diastolic rumble along the left sternal border. S1 is normal and the splitting of S2 does not change with inspiration. Which of the following is the most likely diagnosis?