This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
WPW syndrome is caused by 
Select and explain. 
A. Bundle Branch Block, B. Right sided accessory pathway, C. Ectopic pacemaker in atrium, D. Left budle Branch block
A: Bundle Branch Block
Answer: A: Bundle Branch Block 
Explanation: Ans. is 'b' i.e., Right sided accessory pathway Anatomy (Location ofAccessory pathway) in W.R W syndrome Electrophysiological studies and mapping have shown that accessory. Atrioventricular pathways may be located anywhere along the A-V rign or groove in the septum. The most frequent locations are : - Left lateral (50%), posteroseptal (30%) right anteroseptal (10%). Right lateral (10%). Preexcitation resulting from left sided accessory is called type A preexcitation. Preexcitation resulting from right sided accessory pathway is called type B preexcitation.