ECG ECG Artifacts and Troubleshooting 2

Question 1

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

Accepted Answer

Right arm and left arm electrode reversal

Answer

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.

Question 2

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

Accepted Answer

Right arm and left arm electrode reversal or disconnection

Answer

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.

Question 3

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

Accepted Answer

Check the right leg (RL) ground electrode connection

Answer

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

Question 4

Respiratory artifact causes the ECG baseline to undulate at approximately:

Accepted Answer

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

Answer

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

Question 5

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

Accepted Answer

Precordial leads V1–V4

Answer

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.

ECG (Electrocardiogram) Practice Test

ECG (Electrocardiogram) Practice Test

ECG ECG Artifacts and Troubleshooting 2