CVT Electrocardiography (ECG/EKG) Techniques 3

Question 1

A technician notices the QRS complexes alternate in amplitude on an ECG strip. This finding is called:

Accepted Answer

Electrical alternans

Answer

Electrical alternans is characterized by beat-to-beat variation in QRS amplitude and can indicate pericardial effusion or cardiac tamponade.

Question 2

Which electrode placement error causes the most clinically significant ECG distortion?

Accepted Answer

Left arm and right arm leads reversed

Answer

Reversing the left arm (LA) and right arm (RA) electrodes inverts lead I and swaps aVL and aVR, which can mimic dextrocardia or mask pathology.

Question 3

The QTc interval is calculated to correct for heart rate. Which formula is most commonly used?

Accepted Answer

Bazett formula

Answer

The Bazett formula (QTc = QT / √RR) is the most widely used method for heart rate correction of the QT interval despite its limitations at extreme rates.

Question 4

Posterior wall MI is best identified on a standard 12-lead ECG by which finding in leads V1–V2?

Accepted Answer

Tall R waves and ST depression

Answer

Posterior MI produces reciprocal changes in V1–V2: tall, broad R waves and ST depression representing the mirror image of posterior ST elevation and Q waves.

Question 5

To reduce 60-Hz AC interference on an ECG tracing, a technician should first:

Accepted Answer

Check and re-prep electrode sites

Answer

Poor electrode-to-skin contact is the most common cause of AC interference; re-prepping the skin with abrasive prep and fresh gel usually eliminates it.

(CVT) Cardiovascular Technologist Certification Practice Test

(CVT) Cardiovascular Technologist Certification Practice Test

CVT Electrocardiography (ECG/EKG) Techniques 3