CRAT ECG Troubleshooting and Artifacts 3

Question 1

A rhythm strip shows regular QRS complexes intermixed with artifact spikes from a patient's implanted pacemaker. How can you best distinguish paced beats from artifact?

Accepted Answer

Paced beats are followed by a wide QRS complex after each pacemaker spike

Answer

True pacemaker spikes are immediately followed by a ventricular depolarization (wide QRS), while artifact spikes from external sources have no consistent relationship to cardiac complexes.

Question 2

Standard ECG paper runs at which speed?

Accepted Answer

25 mm/sec

Answer

Standard ECG paper speed is 25 mm/second, making each small box (1 mm) equal to 40 ms and each large box (5 mm) equal to 200 ms.

Question 3

Which chest electrode position is placed at the fourth intercostal space to the right of the sternum?

Accepted Answer

V1

Answer

V1 is placed at the fourth intercostal space just to the right of the sternal border, providing the key reference lead for P wave morphology and bundle branch block analysis.

Question 4

A patient with shivering produces ECG artifact that closely resembles which serious arrhythmia?

Accepted Answer

Atrial fibrillation

Answer

Muscle tremor artifact from shivering produces irregular rapid baseline oscillations that can mimic the irregular fibrillatory baseline of atrial fibrillation.

Question 5

When performing a 12-lead ECG, the RL (right leg) electrode serves primarily which purpose?

Accepted Answer

Electrical ground/reference to reduce common-mode noise

Answer

The right leg electrode serves as the ground electrode, providing a common reference point that helps the ECG machine cancel out common-mode electrical noise affecting all leads equally.

CRAT - Certified Rhythm Analysis Technician Practice Test

CRAT - Certified Rhythm Analysis Technician Practice Test

CRAT ECG Troubleshooting and Artifacts 3