Korean J Aerosp Environ Med.
2000 Dec;10(4):329-335.
Echocardiographic evaluation of USAF pilots with Aortic Insufficiency(AI):
Is the flying of High Performance Aircraft(HPA) detrimental to pilots with AI?
- Affiliations
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- 1PO BOX 304-220 Gumsa-Dong, Dong-Gu, Daegu-kwangyuk Si, ROK.
Abstract
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BACKGROUND AND METHOD: For decades, the presence of aortic insufficiency (AI) has been
considered a potential hazard in military aviation and has generally excluded aircrew
from high performance flight. The cardiovascular effect of repeated exposure of high +Gz
forces associated with AI is largely unknown. To evaluate whether the flying of High
Performance Aircraft (HPA) was detrimental to subjects with AI, we performed a retrospective
review. we studied 32 asymptomatic patients in whom 16 of them had flying time with AI
in HPA(Group I), others(GroupII, Control Gr.) in Low-G Aircraft(LGA). Among them, the data
of 24 patients were available, 12 in group I., and 12 in group II. The two groups were
matched for age, severity of AI, and flying time.
RESULTS
Interval echocardiographic, and cineangiographic studies were obtained over a mean
period of 4.6+/-2.6 years in group I and 5.9+/-4.2 years in group II (range, 0.9 to 12.7 years)
and mean flying time with AI of 528.1+/-435.0 hours in group I and 865.0+/-816.1 hours
in group II (range, 50 to 2290 hours).
By paired-t test, there were no significant differences between both groups in left
ventricular end-diastolic dimension (LVEDD), end-systolic dimension (LVESD), aortic
dimension (Ao.D) and fractional shortening (FS) by echocardiography (p>0.05) and by multiple
linear regression, there were no significant interval changes of above values
in Gr. I according to increasing of flying time with AI (p>0.05). Visual grade by doppler
echocardiography or aortic cineangiography increased 1 patient in Gr.I and 2 patients in
Gr.II within no more than one grade.
CONCLUSION
Thus, this study demonstrated that : 1) Quantitative echocardiographic
measurements such as LEVDD, LVESD, Ao.D and FS didn't show significant interval change
in Gr.I.2) A single subject with a minor increase in AI severity together with no
difference between the HPA and LPA groups argue for a relatively chronic effect of high G
exposure in aircrew with mild AI.