Regulations were recommended by the NTSB (National Transportation Safety Board) that would prevent pilots with certain heart conditions and who are taking certain medications from participating in aerobatic flight.  Opposing these recommendations are the Experimental Aircraft Association (EAA) and the Civil Aeromedical Association (CAMA).  

The NTSB argues that using certain heart medication can make pilots more susceptible to G-forces, lowering their G-tolerance and possibly causing G-LOC, a G-induced loss of consciousness. However, many factors such as weight, height, and degree of physical fitness can also influence G-tolerance levels.  The NTSBs broad recommendations would needlessly restrict hundreds of pilots from participating in aerobatic flight.  According to the AOPA, only 1.9% of general aviation accidents occur because of medical factors as an even partial cause.  Because of this, the EAA and CAMA have urged  the FAA to review accident information to determine whether cardiac conditions or certain prescribed medicine can be considered as a potential risk.