Echocardiographic evaluation and follow-up of cardiac and aortic indexes in aviators exposed to acceleration forces.

BACKGROUND

Military jet fighter pilots are routinely exposed to acceleration (+Gz) forces. This recurrent exposure may influence various cardiac parameters. A few previous studies have evaluated the impact of exposure to acceleration forces on cardiac morphology and function, but these studies were mostly based on small cohorts, and subjects did not undergo baseline echocardiographic examinations before +Gz exposure.

METHODS

Ninety-six jet fighter pilots with high +Gz exposure underwent echocardiographic evaluation before and 7 to 12 years after repeated +Gz exposure. Echocardiographic parameters were recorded using M-mode echocardiography and included left ventricular diameter at end-systole and end-diastole, interventricular septal thickness, thickness of the posterior wall, aortic root diameter and aortic valve opening, diameter of the left atrium, and left ventricular mass. Medical records of the subjects identified were evaluated for the development of adverse events.

RESULTS

The average age at the time of the initial echocardiographic examination was 19.2 years. All subjects were healthy, without cardiovascular risk factors, and had no prior exposure to acceleration forces. The average flying period on jet planes at the time of follow-up examination was 1,812 hours. The mean follow-up period was 9.13 years. All parameters evaluated by M-mode echocardiography were not significantly changed from the baseline examination. No adverse events occurred during the follow-up period.

CONCLUSIONS

Exposure to acceleration forces has no significant impact on cardiac and aortic morphology.