Why can't a patient with a pacemaker (permanent artificial cardiac pacemaker) get a FibroScan (transient elastography)?

Why Patients with Pacemakers Can Safely Undergo FibroScan

Patients with cardiac pacemakers can safely undergo FibroScan (transient elastography) despite previous manufacturer contraindications, as clinical evidence shows no interference between these devices. 1

Understanding the Concern

Historically, there has been concern about potential electromagnetic interference between medical devices that emit energy fields and implanted cardiac devices such as pacemakers. These concerns were based on theoretical risks rather than clinical evidence:

1. Theoretical electromagnetic interference: FibroScan uses vibration-controlled transient elastography technology that could theoretically interfere with pacemaker function
2. Manufacturer precautions: Many device manufacturers have traditionally listed pacemakers as contraindications in their product documentation as a precautionary measure

Clinical Evidence Supporting Safety

Recent research has definitively addressed this concern:

• A comprehensive clinical study specifically examining FibroScan safety in patients with cardiac devices found no adverse events in 107 subjects with 33 different types of implanted cardiac devices from 5 different manufacturers 1
• This study included high-risk subjects who were actively pacing (53 patients) and even a patient with right pectoral pacemaker placement (closest to the liver) 1
• No abnormal device sensing/pacing or ICD firing was observed during FibroScan testing 1

Current Guideline Recommendations

The 2017 Clinical Practice Guidelines for Video Capsule Endoscopy, which addresses similar electromagnetic concerns, states:

• "In patients with a pacemaker, we suggest that CE (capsule endoscopy) can be performed without special precautions" 2
• The guidelines note that while manufacturers may list pacemakers as contraindications, "there appears to be little clinical evidence supporting this" 2

Understanding Pacemaker-Device Interactions

Not all electronic devices pose equal risk to pacemakers:

• Devices that emit high-energy, pulsed low-frequency electromagnetic fields (like acoustomagnetic systems) are more likely to interfere with pacemakers 3
• FibroScan's technology does not produce the type of electromagnetic field known to cause pacemaker interference
• Modern pacemakers have improved shielding and filtering capabilities that reduce susceptibility to external electromagnetic interference 4

Clinical Implications

For healthcare providers managing patients with pacemakers who need FibroScan:

• No special precautions are required for routine FibroScan in patients with pacemakers 2, 1
• Standard pacemaker follow-up should continue according to established guidelines 2
• Patients should be reassured that the procedure is safe based on clinical evidence

Common Pitfalls to Avoid

1. Unnecessary procedure avoidance: Denying beneficial diagnostic procedures based on outdated theoretical concerns
2. Confusing different electromagnetic technologies: Not all devices that emit electromagnetic fields pose the same risk to pacemakers
3. Relying solely on manufacturer warnings: These are often overly cautious and may not reflect current clinical evidence

In conclusion, while historical concerns existed about potential interference between FibroScan and cardiac pacemakers, current clinical evidence demonstrates that FibroScan can be safely performed in patients with pacemakers without special precautions or monitoring.