Cardiac HealthStream Telemetry Practice Exam

Line noise artifact shows up as rapid, high-frequency spikes or jagged activity that ride on the ECG baseline in an irregular pattern. It’s a type of electromagnetic interference that distorts the tracing rather than reflecting the heart’s electrical activity. The best way to mitigate it is to ensure the leads are firmly and properly attached, with good skin contact. This means reapplying or re-securing the leads after skin preparation and verifying that impedance is acceptable. Also minimize electrical interference by keeping the patient away from nearby devices that emit EMI, turning off nonessential equipment when possible, and ensuring the monitor and its power source are properly grounded. Inspect and replace any damaged leads, use shielded cables if available, and keep lead wires tidy and well separated to reduce cross-talk. For contrast, slow, rhythmic baseline wander from respiration is not line noise, and a flat line during movement suggests a lead disconnection, not line noise.