ECG Clinical Applications

Question 1

What is the standard number of leads in a 12-lead ECG?

Accepted Answer

12 leads from 10 electrodes

Answer

12 leads from 12 electrodes

Answer

10 leads from 10 electrodes

Answer

6 leads from 6 electrodes

Question 2

Where should the V4 precordial electrode be placed?

Accepted Answer

Fifth intercostal space at the midclavicular line

Answer

Fourth intercostal space right sternal border

Answer

Fifth intercostal space at the anterior axillary line

Answer

Second intercostal space left sternal border

Question 3

Why is a baseline ECG important before starting certain medications?

Accepted Answer

To detect pre-existing QT prolongation or other abnormalities

Answer

To determine the patient's blood pressure

Answer

To measure oxygen saturation

Answer

To assess lung function

Question 4

What artifact can be caused by patient movement during ECG recording?

Accepted Answer

Wandering baseline and muscle tremor artifact

Answer

ST elevation

Answer

Peaked T waves

Answer

Bundle branch block pattern

Question 5

When should a 12-lead ECG be performed for a patient with chest pain?

Accepted Answer

Within 10 minutes of arrival

Answer

After blood work results return

Answer

Only if symptoms persist for 1 hour

Answer

At the next scheduled appointment

Question 6

What does reciprocal change mean on an ECG?

Accepted Answer

ST depression in leads opposite to those showing ST elevation

Answer

Identical changes in all 12 leads

Answer

P waves appearing after QRS complexes

Answer

T wave inversion in limb leads only