ECG Artifacts and Troubleshooting Flashcards

If lead aVR shows a positive deflection in all waveforms, what should the technician check?

Answer: Right arm and left arm electrode reversal

Lead aVR normally shows predominantly negative deflections; if it appears positive, right arm (RA) and left arm (LA) electrode reversal is the most likely cause.

A nearly flat (isoelectric) tracing in lead I suggests which electrode problem?

Answer: Right arm and left arm electrode reversal or disconnection

Lead I measures the potential difference between RA and LA; if both electrodes are on the same limb or disconnected, lead I will appear flat or isoelectric.

Which step should be taken first when all leads simultaneously show poor quality?

Answer: Check the right leg (RL) ground electrode connection

The right leg (RL) electrode serves as the ground reference for all leads; a loose or disconnected RL electrode degrades every lead simultaneously.

Respiratory artifact causes the ECG baseline to undulate at approximately:

Answer: The patient's respiratory rate (12–20 cycles/min)

Respiratory artifact cycles at the patient's breathing rate (typically 12–20 breaths/min), producing slow, rhythmic baseline shifts synchronized with respiration.

When precordial electrodes are placed too high on the chest, which leads are most affected?

Answer: Precordial leads V1–V4

Precordial leads V1–V4 are most sensitive to vertical misplacement because they overlie the upper heart; high placement alters R-wave progression and ST morphology.

What is the correct action when a patient's diaphoresis (sweating) causes electrodes to slip?

Answer: Dry the skin thoroughly and use additional securing tape before reattaching

Drying the skin thoroughly and securing electrodes with additional tape or cloth stabilizes electrode contact in diaphoretic patients, improving signal quality.