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Magnetism and cardiac arrhythmias
Benjamin J Scherlag1, William S Yamanashi, Yuemei Hou
1Cardiac Arrhythmia Research Institute at the University of Oklahoma Medical Center, Oklahoma City, OK 73104, USA. benjamin-scherlag@ouhsc.edu
Cardiology in Review
|February 10, 2004
Summary
Low-level electromagnetic fields (EMFs) significantly altered heart rate and atrioventricular conduction in dogs. These EMFs also influenced heart rhythm, with effects mediated by the autonomic nervous system.
Area of Science:
- Cardiovascular Physiology
- Neuroscience
- Biophysics
Background:
- Low-level electromagnetic fields (EMFs) show potential for treating neurological disorders.
- The influence of EMFs on the autonomic nervous system and cardiac function requires further investigation.
Purpose of the Study:
- To investigate the effects of specific low-level EMFs on heart rate, atrioventricular conduction, and cardiac rhythm in anesthetized dogs.
- To determine if these EMF effects are mediated through the autonomic nervous system.
Main Methods:
- Application of low-level EMFs (microG levels) to vagosympathetic nerve trunks or across the chest in dogs.
- Comparison of EMF exposure with sham controls.
- Assessment of heart rate, atrioventricular conduction, and induction of atrial arrhythmias before and after EMF exposure, with and without autonomic blockade.
Main Results:
- EMF exposure (2.87 microG at 0.043 Hz) to vagosympathetic trunks decreased heart rate by 29% and reduced the voltage needed for AV block by 60%.
- A different EMF setting (0.34 microG at 2 kHz) increased the occurrence of atrial arrhythmias upon autonomic nerve stimulation.
- EMF application across the chest suppressed induced atrial fibrillation for up to 3-4 hours.
Conclusions:
- Specific low-level EMFs can modulate cardiac autonomic function, affecting heart rate, AV conduction, and rhythm.
- The observed effects are likely mediated via the autonomic nervous system, as evidenced by autonomic stimulation and blockade experiments.
- These findings suggest a potential role for targeted EMFs in managing cardiac autonomic dysregulation.