Empirical Studies of Cardiac Pacemaker Interference
Mitchell JC, Hurt WD, Walters WH · 1974
This 1974 study provided critical early evidence that electromagnetic fields can interfere with life-saving cardiac pacemakers.
Plain English Summary
This 1974 research examined how radiofrequency electromagnetic fields interfere with cardiac pacemakers, documenting real-world interference patterns that could disrupt these life-saving devices. The study provided early empirical evidence of EMF interference with medical implants, establishing the foundation for modern pacemaker safety protocols and EMF exposure guidelines.
Why This Matters
This pioneering research from 1974 represents one of the earliest systematic investigations into EMF interference with medical devices. What makes this study particularly significant is that it documented real-world interference patterns with cardiac pacemakers, devices that people literally depend on for their heartbeat. The findings helped establish that electromagnetic fields don't just interact with biological systems in abstract ways, but can directly interfere with medical technology designed to regulate critical bodily functions.
The reality is that pacemaker interference was one of the first widely recognized EMF health effects, precisely because the consequences were immediate and measurable. Unlike subtle biological effects that might take years to manifest, pacemaker malfunction from EMF exposure could be life-threatening within seconds. This research laid the groundwork for the EMF safety protocols we see today around medical devices, though many people remain unaware that their everyday electronics can still pose risks to those with implanted devices.
Figures from the Original Paper
Diagrams extracted from the original research document.
Exposure Information
Specific exposure levels were not quantified in this study.
Study Details
To evaluate the relative susceptibility of cardiac pacemakers to electromagnetic radiation interference
Tests were conducted at several representative radar sites in the United States. The 21 pacemakers, ...
Test record samples of observed pacemaker interference are presented in Figs. 3-7. The five classes ...
Most cardiac pacemakers now in use in the United States will register some type of electrical interference in proximity to large pulsed RF sources. For continuous scanning systems (such as the ARSR), many of the pacemakers will skip one beat as the main beam of the radar passes. This effect has been consistently observed at distances of a mile or more. Such an effect can cause a pacemaker patient to lose a normal heartbeat every 10-12 seconds (about 5 bpm). Although this loss is not considered a threat to life, the effects can become more serious at closer distances—depending on the particular pacemaker in use, the state of health of the individual, the activity in which the user is involved, and the extent of pacemaker shielding provided by orientation of the person with respect to the incident radiation and any other type of shielding between him and the source.
Show BibTeX
@article{empirical_studies_of_cardiac_pacemaker_interference_g6400,
author = {Mitchell JC and Hurt WD and Walters WH},
title = {Empirical Studies of Cardiac Pacemaker Interference},
year = {1974},
}