This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hea Sounds, Subject name: Medicine
An 18-year-old boy is brought to the hospital with loss of consciousness. He regains consciousness in the ER, and GCS on admission is 12/15. CNS examination is normal and auscultation reveals a narrow split S2 and clear lungs. ECG was done. Diagnosis is? 
Select and explain. 
A. Left outflow tract obstruction, B. Right outflow tract obstruction, C. Atrial fibrillation with cerebral embolism, D. Subarachnoid hemorrhage with T wave inversion
A: Left outflow tract obstruction
Answer: A: Left outflow tract obstruction 
Explanation: The ECG shows a hea rate of 60/min with left axis detion SV1+RV5> 35 mm is suggestive of left ventricular hyperophy SV1 = 20mm and RV5= 30mm Narrow split S2 indicates outflow tract obstruction Taking into consideration the age, the patient either suffers from HOCM or valvular aoic stenosis. The low cardiac output can lead to exeional syncope.