Paradoxical splitting of second hea sound is seen in-

A split S2 is a finding upon auscultation of the S2 hea sound. It is caused when the closure of the aoic valve (A2) and the closure of the pulmonary valve (P2) are not synchronized during inspiration. The second hea sound (S2) is caused by the closure of the aoic and pulmonic valves, which causes vibration of the valve leaflets and the adjacent structures. The aoic valve closes slightly before the pulmonic, and this difference is accentuated during inspiration when S2 splits into two distinct components (physiological splitting). During expiration, the pulmonic valve closes at nearly the same time as the aoic, and splitting of S2 cannot be heard Exercise increases the intensity of both the aoic and pulmonic components of S2, whereas deep inspiration increases the intensity of the pulmonic component only. Ref Harrison 20th ed pg 1456