Asymptomatic Wolff-Parkinson-White Pattern ECG in USAF Aviators

INTRODUCTION: Wolff-Parkinson-White (WPW) pattern is occasionally found in asymptomatic aviators during routine ECGs. Aeromedical concerns regarding WPW pattern include risk of dysrhythmia or sudden cardiac death (SCD), thus affecting the safety of flight. The purpose of this study was to determine the prevalence and outcomes of aviators with asymptomatic WPW pattern and assess for risk factors that contribute to progression to dysrhythmia or symptoms. METHODS: The U.S. Air Force (USAF) ECG library database containing over 1.2 million ECGs collected over the past 68 yr was used to identify 638 individual aviators with WPW pattern. Demographic, medical history, and outcome data were obtained by medical record review. Aviators who developed high risk features defined as symptoms, arrhythmia, or ablation of a high risk pathway, were compared to those who remained asymptomatic. RESULTS: Prevalence of WPW pattern was 0.30% among all USAF aviators. Of the 638 individuals, 64 (10%) progressed to the combined endpoint of SCD, arrhythmia, and/or ablation of a high risk pathway over 6868 patient years, with average follow-up of 10.5 yr. There were two sudden cardiac deaths (0.3%). Annual risk of possible sudden incapacitation was 0.95% and of SCD 0.03%. Those that progressed to high risk were significantly younger, had lower diastolic blood pressure, lower total cholesterol, and better physical fitness testing scores. DISCUSSION: WPW pattern on ECG found in asymptomatic aviators confers < 1% annual risk of arrhythmia or incapacitating events with the highest risk in the younger, healthier, and most fit populations.