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Oversensing and noise

An ICD & CRT Therapy term on the RCES exam blueprint, defined for cath lab and EP clinicians.

Sources include lead fracture/insulation failure (intermittent, often correlated with patient movement), myopotential oversensing (skeletal muscle electrical activity, particularly with unipolar sensing configurations), and external electromagnetic interference — each has characteristic signal patterns on interrogation that help localize the cause before assuming a true arrhythmia occurred.

Domain: ICD & CRT Therapy · Blueprint: RCES exam guide

Related RCES terms

Defibrillation threshold (DFT) testing Lead extraction MRI-conditional devices and protocols Tiered therapy programming AV and VV delay optimization

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Written and reviewed by John-Philip (JP) Maarschalk, BSN, RN, CNML — a nurse manager who runs operations for the cardiac cath lab, electrophysiology, and interventional service lines at an academic health system in North Carolina. He hires and develops the staff who sit for these exams. More about JP and how this content is made →
Cardiac Codex is an independent study tool published by MdoubleA LLC, not affiliated with or endorsed by CCI or any certifying body. This glossary entry is exam-preparation information, not medical advice or a substitute for clinical judgment. Always verify current clinical practice against primary sources and institutional protocol.