Basic ECG Interpretation Questions with Correct Answers

Basic ECG Interpretation Questions
with Correct Answers
Question 1 of 4
Match the property of the cardiac conduction system with its description.
Property of the cell that allows it to accept initiation of stimulation
-Excitability
Property that moves electrical impulse along a membrane
-Conductivity
Ability of heart muscle to respond mechanically to an impulse
-Contractility
Ability of heart muscle to initiate an impulse, begin stimulation
-Automaticity - ANSWERS

Question 2 of 4
List in order the pathway of the normal cardiac impulse starting at the SA node.
The impulse causes the atria to contract.
The impulse travels from the AV node through the bundle of His.
The impulse divides into the left and right bundle branches.
The impulse reaches the Purkinje fibers.
The ventricles contract. - ANSWERS

Question 3 of 4
An increase in the rate of cardiac impulse initiation is linked to stimulation of which
component?
Purkinje system
Electrolyte system
Sympathetic nervous system
Parasympathetic nervous system - ANSWERSSympathetic nervous system
The sympathetic nervous system is responsible for increasing the rate of cardiac
impulse initiation at the SA node. It also assists with node impulse conduction and
cardiac contractility.

Question 4 of 4
Which electrolytes play key roles in polarization of the heart cells?
Sodium and potassium
Potassium and calcium
Potassium and glucose
Sodium and magnesium - ANSWERSSodium and potassium
The electrolytes sodium and potassium are partners in cardiac function. A higher
sodium level outside the cell allows for a high potassium and low sodium level inside the
cell. Potassium inside the cell is required for the conduction of impulses to achieve a
polarized state.

, Question 1 of 4
Which wave on the ECG tracing will provide the nurse more information about atrial
depolarization?
A
B
C
D - ANSWERSB
The P wave demonstrates the initial firing of the SA node. The P wave can display as
positive (upright), negative (inverted), or biphasic (both positive and negative).

Question 2 of 4
A patient asks the nurse, "Why do I need a 12-lead ECG if my heart rate is within
normal limits?" The nurse responds by explaining that which heart conditions may be
identified by the 12-lead ECG?
Select all that apply.
Cardiotoxicity
Cardiac murmur
Irregular rhythm
Myocardial infarction
Heart valve deformation - ANSWERSCardiotoxicity
The 12-lead ECG may show changes indicative of drug toxicity.

Irregular rhythm
Obtaining 12-lead ECG views of the heart is helpful in the assessment of dysrhythmias,
or irregular heart rhythms.

Myocardial infarction
The 12-lead ECG may show changes suggesting damage to the heart including
ischemia and myocardial infarction.

Question 3 of 4
Which ECG component would the nurse measure to identify the total time needed for
ventricular depolarization and repolarization of a patient's heart?
A
B
C
D - ANSWERSD
The QT interval is the time it takes for ventricular depolarization and then repolarization.
It is calculated by measuring the distance between the QRS complex and the T wave.

Question 4 of 4
The nurse is assessing heart rate from a patient's ECG and counts 8 R-R intervals in a
6-second stretch. The patient's heart rate is __________
beats per minute.
Use numbers only. - ANSWERS80