...And the Beats Keep Runnin Runnin (In Space)

Introduction: This case series describes the medical clearance of
NASA astronauts after diagnosis of atrial fibrillation seeking to fly to
the International Space Station (ISS). BACKGROUND: Atrial fibrillation is
the most common sustained arrhythmia with increasing incidence with
age and is associated with increased lifetime risk of stroke. Treatment
may consist of pharmacologic rate control and anticoagulation.
Although it is not yet known how spaceflight modifies risk of cardioembolic
event or adverse treatment effects, these can have significant
impact on mission and crew health for spaceflight and granting a
medical waiver for flight is a complex, case-by-case consideration.

Case Presentation: We reviewed all records of waivers granted by NASA
for atrial fibrillation and flutter, and identified 6 cases (4 short-duration
[<18 days] and 2 long-duration missions [>60 days]) where waiver was
granted with subsequent spaceflight. DISCUSSION: NASA has approved
astronauts with a history of atrial fibrillation or flutter for flight following
an appropriate medical evaluation. With the high prevalence of atrial
fibrillation in the general population, we anticipate that consideration
of medical waiver will become increasingly common as commercial
spaceflight grows. These cases provide a potential framework for risk
assessment and management of this population, to balance potential
risk modification inherent in the microgravity environment against
implications to crew performance, mission success, and personal health
of spaceflight participants