This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Medicine
Reverse splitting of 2nd hea sound heard in - 
Select and explain. 
A. RBBB, B. LBBB, C. Tricuspid stenosis, D. AR
B: LBBB
Answer: B: LBBB 
Explanation: In LBBB, Left ventricular depolarisation is late than RV depolarisation, so A2 appeares late than P2. Causes of Reverse splitting : RV pacemaker WPW syndrome Eisen menkers syndrome AS LVF LBBB Ref : Harrison's 20th edition pg 1448