The most common accessory pathways leading to WPW syndrome is -

Ans. is 'a' i.e., Left free wall o Wolf - Parkinson white syndrome is a condition in which episodes of fast heart rate (called tachycardia) occur because of an abnormal extra electrical pathway in the heart,o Patients with W.P.W. syndrome have on extra electrical pathway between the atria and ventricles known as accessory pathways.o The abnormal pathway- directly connects the atria and ventricles at a site other than the A. V. node. It allows the electrical activity to bypass the A. V node.Anatomy (Location of Accessory pathway) in W.P.W. syndromeo Electrophysiological studies and mapping have shown that accessory. Atrioventri pathways may be located anywhere along the A-Vrign or groove in the septum.o The most frequent locations are: -Left lateral (50%), posteroseptal (30%) right anteroseptal (10%).Right lateral (10%).o Preexcitation resulting from left sided accessory is called type A preexcitation.o Preexcitation resulting from right sided accessory pathway is called type B preexcitation.