Current epidemiological data suggest that sinus node dysfunction is a relatively uncommon condition in the pilot age group. Symptomatic pauses of any mechanism suggest disqualification from flying duties. Asymptomatic pauses (representing sino-atrial block or sinus node arrest) demand further investigation and regular follow-up. Idiopathic pauses greater than 2.5 s on an ambulatory ECG is abnormal and is likely to deny flying status.