<prompt> In all cases intensity of murmur increases on sit-up and hand grip except?MSHOCMASTR  <response>: On standing: The venous return is going be reduced there is decrease blood coming to the hea, therefore intensity of murmurs get reduced. Eg : Valsalva, Amyl nitrate Except HOCM: louder murmur; MVP: longer murmur Note: All murmurs increase on doing sit ups, hand grip as there is increase of peripheral resistance HOCM: soften MVP: shoer HOCM: AD defect in chromosome 14, b- myosin gene disorder 