Contractile fibroblasts (myofibroblasts) in a painful pacemaker pocket

Area of Science:

• Cardiovascular Science
• Biomedical Engineering
• Pathology

Background:

• Cardiac pacemakers are vital medical devices.
• Fibrous capsule formation around implants is a known phenomenon.
• Understanding implant-associated pain is crucial for patient outcomes.

Observation:

• Electron microscopy revealed myofibroblasts within the fibrotic capsule of a painful pacemaker.
• Myofibroblasts exhibit characteristics of both smooth muscle cells and fibroblasts.
• These cells are implicated in wound and scar contraction.

Findings:

• The painful fibrotic capsule around the cardiac pacemaker contains myofibroblasts.
• Myofibroblast activity, leading to scar contraction, is likely the cause of pacemaker-related pain and tenderness.
• The observed scar tissue resembles that around other inert thoracic implants.

Implications:

• This study suggests scar tissue contraction as a mechanism for pacemaker-associated pain.
• Findings may inform strategies to mitigate implant-related fibrosis and discomfort.
• Further research into myofibroblast modulation could improve device tolerability.