Activity-sensing permanent internal pacemaker dysfunction during helicopter aeromedical transport

Area of Science:

• Biomedical Engineering
• Aerospace Medicine

Background:

• Activity-sensing pacemakers are crucial for patients with cardiac conditions.
• Helicopter aeromedical transport presents unique environmental challenges, including vibration and rotor motion.
• Potential pacemaker dysfunction during transport could compromise patient care.

Purpose of the Study:

• To determine the incidence, severity, and causes of activity-sensing pacemaker malfunction during helicopter transport.
• To evaluate the impact of helicopter flight conditions on pacemaker function.

Main Methods:

• Two Medtronic Activitrax pacemaker models were externally attached to four healthy volunteers.
• Volunteers underwent helicopter flights in Aerospatiale Dauphin and Twinstar models.
• Pacemaker heart rates were recorded during flight sequences, with interventions including magnet application and reprogramming.

Main Results:

• Average pacemaker rate increased from 65 bpm preflight to 105 bpm in-flight.
• This rate increase consistently resolved upon helicopter shutdown.
• External magnet application effectively prevented the in-flight rate increase.

Conclusions:

• Rotor motion and flight vibration predictably affect Activitrax pacemaker rate-response.
• Pacemaker function during helicopter transport is manageable through reprogramming or magnet use.
• Guidelines for safe patient transport with pacemakers are proposed.