Systolic pressure gradient across aoic valve is elevated in -

The obstruction to LV outflow produces a systolic pressure gradient between the LV and aoa. AS increases in severity, LV systole may become prolonged so that the aoic valve closure sound no longer precedes the pulmonic valve closure sound, and the two components may become synchronous, or aoic valve closure may even follow pulmonic valve closure, causing paradoxical splitting of S 2 The murmur of AS is characteristically an ejection (mid) systolic murmur that commences sholy after the S 1 , increases in intensity to reach a peak toward the middle of ejection, and ends just before aoic valve closure . It is characteristically low-pitched, rough and rasping in character, and loudest at the base of the hea, most commonly in the second right intercostal space. ( Harrison&;s principle of internal medicine,18th edition,pg no. 1939)