Acceleration tolerance of asymptomatic aircrew with mitral valve prolapse.

Using the USAF School of Aerospace Medicine human centrifuge, 78 asymptomatic USAF aircrewmen with auscultatory and/or echocardiographic evidence of mitral valve prolapse (MVP) were evaluated for tolerance to +Gz stress. Both rapid (1G X s-1) and gradual (1G X 15 s-1) onset acceleration profiles were used to determine +Gz tolerance. There were no unusual characteristics, among the clinical parameters measured, which allowed separation of individuals with MVP into subgroups with altered +Gz tolerance. The MVP group was found to have a normal response to gradual onset +Gz stress, both while relaxed and when performing a protective straining maneuver. A small but statistically significant decrease in tolerance to rapid onset +Gz stress was found. There was no indication that asymptomatic individuals with MVP who have undergone complete aeromedical evaluation have any operationally significant intolerance to +Gz stress.