1) I am in the same situation, but mine was extremely mild
2) My advice
. . . walk around, but sit when he feels a little tired - don't wait for exhaustion
. . . if walking is too tiring, get an
ECV electric cart
. . . drink lots of fluids to avoid dehydration
. . . carry his emergency meds (eg. aspirin or digitalis), just in case
. . . don't do the real thrill rides - ToT, RnRC, Body Wars
. . . the Star Tours ride is questionable, but fine for me
. . . semi-thrill rides should be fine - Splash Mountain, BTM, Space Mountain
. . . high g-force rides should be avoided - MISSION:SPACE, Tea Cups
NOTE: The non-thrill coasters and rides may be a little jolty, but aren't big on g-forces. Yes, I know that Tea Cups is a "kid's" ride, but if it gets spinning, it can build up enough g-force to put excess pressure on the system.