Holter monitor findings in asymptomatic male military aviators without structural heart disease.

PURPOSE: Our study was designed to determine the spectrum of Holter monitor findings in normal male military aviators to establish a reference for aircrew populations with cardiac related diagnoses.
METHODS: We identified all individuals with normal cardiac catheterization in the United States Air Force Aeromedical Consultation Service cardiac catheterization database from January 1984 to December 1998. Cases with valvular disease, left or right bundle branch block, and referral diagnoses of ectopy or arrhythmia were then excluded. Results of Holter monitor studies performed on the remaining aviators prior to cardiac catheterization were then collected and tabulated. Frequency of isolated ectopy was classified as a percentage of the total beats on the Holter monitor: rare (< or =0.1%), occasional (>0.1 to 1.0%), frequent (>1.0 to 10%) and very frequent (>10%).
RESULTS: From 1575 consecutive cardiac catheterizations reviewed, 303 aviators met the above inclusion criteria. Only 36 of 303 (11.9%) had no ectopy at all. Rare, occasional, frequent and very frequent isolated atrial ectopy occurred in 72.9%, 2.6%, 2.3% and 0.3%, respectively. The same categories of isolated ventricular ectopy occurred in 40.9%, 7.9%, 3.3% and 0.0%. Atrial and ventricular pairs occurred in 14.5% and 4.3%, respectively. Nonsustained supraventricular and ventricular tachycardia (duration 3 to 10 beats) occurred in 4.3% (13/303) and 0.7% (2/303), respectively. There were no sustained supraventricular or ventricular tachycardias.
CONCLUSIONS: In this population, absence of ectopy is unusual while rare isolated ectopy is common. These findings may help define the aeromedical/clinical significance of Holter monitors performed on aircrew with underlying cardiac complaints or diagnoses.