Characteristics of the standard 12-lead Holter ECG in professional firefighters

Firefighters have twice as many cardiovascular deaths as police officers and yet there are no available high resolution continuous ECG recordings during firefighting activities. The purpose of this study was to characterize the 12-lead ECG in on-duty professional firefighters. In this prospective descriptive study, all firefighters underwent 24hr ambulatory Holter monitoring using a standard hires 12-lead ECG. Results: 112 firefighters (age 43.6±8yrs, mostly white males) were enrolled over a one year period. During monitoring the average HR was 77 ±10bpm, it range from an average minimum of 47±7 to an average maximum of 143±21 bpm. All were in normal sinus rhythm, however over half of the firefighters had elevated average heart rate and nearly 10% had a widened QRST angle. Conclusion: Among on-duty professional firefighters, high risk ECG markers are present including an elevated average HR and the presence of a widened QRST angle, a high risk marker for fatal cardiac events.