Metal and Implants Do Not Affect Standard ECG Recording
Metal implants and devices within the body do not interfere with the electrical signal acquisition of a standard 12-lead (or 13-lead) ECG. The ECG records electrical potentials at the body surface, and metallic objects inside the chest—including sternal wires, clips, stents, occlusion devices, and prosthetic valves—do not disrupt this recording process 1.
Why Metal Implants Don't Interfere with ECG
ECG measures surface potentials, not internal conductivity: The electrocardiogram detects voltage differences on the skin surface generated by the heart's electrical activity, and this process is unaffected by the presence of internal metallic structures 1.
Guideline consensus confirms safety: The American Heart Association and American College of Cardiology guidelines on ECG technology make no mention of metal implants as a source of artifact or signal interference in standard electrocardiography 1.
Implanted cardiac devices are compatible: Even pacemaker leads and implantable cardioverter defibrillator (ICD) leads, which are metallic and positioned directly within the heart, do not prevent accurate ECG recording 2. These devices may alter the ECG tracing itself (showing pacing spikes or altered QRS morphology), but this reflects the device's electrical activity, not signal interference 1.
Important Distinction: ECG vs. Other Imaging Modalities
Confusion often arises from cardiac MRI restrictions: Metal implants ARE a concern for cardiovascular magnetic resonance imaging, where ferromagnetic objects can cause safety hazards and image artifacts 1. However, this is completely separate from ECG technology.
PET/CT imaging shows artifacts from ICD leads: Research demonstrates that ICD shock coil electrodes can cause significant artifacts in cardiac PET/CT imaging due to their high radioopacity 2. Again, this does not apply to ECG recording.
What Actually Affects ECG Accuracy
The factors that DO compromise ECG quality are entirely different 1, 3:
Electrode misplacement: Superior displacement of V1-V2 or inferior placement of V5-V6 can simulate infarction patterns or alter voltage criteria 1.
Inadequate skin preparation: Poor electrode contact creates noise and baseline wander 1.
Motion artifact: Limb movement during recording introduces electrical noise 1.
Inadequate filtering: Poor high-frequency response (below 150 Hz in adults) causes underestimation of signal amplitude and smoothing of Q waves 3.
External electromagnetic interference: Power lines and other electrical equipment can introduce 60 Hz artifact 1.
Clinical Bottom Line
Proceed with standard ECG recording in any patient with metal implants without concern for signal interference. The presence of sternal wires, joint replacements, dental implants, surgical clips, stents, or prosthetic valves requires no modification to ECG technique or interpretation 1. Focus instead on proper electrode placement, adequate skin preparation, and minimizing patient movement to ensure high-quality tracings 1, 3.