This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Severity of mitral stenosis is assessed by 
Select and explain. 
A. Loud opening snap, B. Length of murmur, C. Loud S1, D. Splitting S2
B: Length of murmur
Answer: B: Length of murmur 
Explanation: Ref Harrison 19 th ed pg 1540 In general, the duration of this murmur correlates with the severity of the stenosis in patients with preserved CO. In patients with sinus rhythm, the murmur often reappears or becomes louder during atrial systole (presystolic accentuation).