Cardiac Dysrhythmias Advanced Questions with
Correct Answers 2026-2027
1. What is the pacemaker of the heart normally? Correct ans -
SA Node. Where does the SA node originate? Correct ans -
Upper right atrium. What is the pathway of conduction in the heart?
Correct ans - SA node
atria -> AV node -> bundle of his -> bundle branches -
> purkinje fibers -> ventricles.
2. What does stimulation of the vagus nerve cause? Correct ans -
Decreased firing of the SA node and slowed impulse conduction of the AV
node.
3. What does stimulation of the sympathetic nerves cause? Correct ans -
Increased firing of the SA node and increased impulse through the AV node, a
nd cardiac contractility.
4. What does the P wave represent? Correct ans -
Time for the passage of the electrical impulse through the atrium causing atri
al depolarization (contraction).
5. What is the normal P wave duration? Correct ans - 0.06 - 0.12.
6. What is a possible variation cause of a P wave? Correct ans -
Disturbance in conduction within the atria.
7. What does the PR interval represent? Correct ans -
The measure from the beginning of the P wave to the beginning of the QRS co
mplex, represents time taken for impulse to spread through the atria, AV node, a
nd bundle of his, the bundle branches and purkinje fibers, to a point of immediat
ely preceding ventricular contraction.
8. What is the normal PRUinterval? Correct ans - 0.12 - 0.20.
9. What is a possible variation cause with PR interval? Correct ans -
Disturbance in conduction usually in the AV node, bundle of his, or bundle
branches but can be atria as well.
10. What does the QRS interval represent? Correct ans -
Measure from beginning to end of QRS complex, represent time taken for d
epolarization (contraction) of both ventricles (systole).
11. What is the normal QRS interval? Correct ans - <0.12.
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, 12. What is a possible variation cause with the QRS interval? Correct ans -
Disturbance in conduction in the bundle branches or in the ventricles.
13. What does the ST Segment represent? Correct ans -
Measure from the S wave of the QRS complex to the beginning of the T wave;
represents time between ventricular depolarization and repolarization (Diastole);
should be isoelectric (flat).
14. What is the normal ST segment? Correct ans - 0.12.
15. What is a possible variation cause with the ST segment? Correct ans -
Disturbance usually caused by ischemia, injury or infarction.
16. What does the T wave represent? Correct ans -
Represents time for ventricular repolarization, should be upright.
17. What is the normal T wave? Correct ans - 0.16.
18. What is a possible variation cause for a T wave? Correct ans -
Disturbance usually caused by electrolyte disturbances; ischemia or i
nfarction.
19. What does the QT interval represent? Correct ans -
Measured from beginning of the QRS to end of the T wave, represents time t
aken for entire electrical depolarization and repolarization of the ventricles.
20. What is the normal QT interval? Correct ans - 0.34 - 0.43.
21. What is the possible variation cause for a QT interval? Correct ans -
Disturbance usually affected repolarization more than depolarization and ca
use by drugs, electrolyte imbalances, and change in hr.
22. What is the normal firing of the SA Node? Correct ans - 60 -
100 times/min.
23. What is the normal firing of the AV Node? Correct ans - 40 -
60 times/min.
24. What is the normal firing of the Bundle of HIS/Purkinje Fibers?
Correct
ans - 20 -
40 times/min.
25. What are the characteristics of Normal Sinus Rhythm? Correct ans -
60 - 100 bpm, regular, normal P wave/PR and QRS.
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Correct Answers 2026-2027
1. What is the pacemaker of the heart normally? Correct ans -
SA Node. Where does the SA node originate? Correct ans -
Upper right atrium. What is the pathway of conduction in the heart?
Correct ans - SA node
atria -> AV node -> bundle of his -> bundle branches -
> purkinje fibers -> ventricles.
2. What does stimulation of the vagus nerve cause? Correct ans -
Decreased firing of the SA node and slowed impulse conduction of the AV
node.
3. What does stimulation of the sympathetic nerves cause? Correct ans -
Increased firing of the SA node and increased impulse through the AV node, a
nd cardiac contractility.
4. What does the P wave represent? Correct ans -
Time for the passage of the electrical impulse through the atrium causing atri
al depolarization (contraction).
5. What is the normal P wave duration? Correct ans - 0.06 - 0.12.
6. What is a possible variation cause of a P wave? Correct ans -
Disturbance in conduction within the atria.
7. What does the PR interval represent? Correct ans -
The measure from the beginning of the P wave to the beginning of the QRS co
mplex, represents time taken for impulse to spread through the atria, AV node, a
nd bundle of his, the bundle branches and purkinje fibers, to a point of immediat
ely preceding ventricular contraction.
8. What is the normal PRUinterval? Correct ans - 0.12 - 0.20.
9. What is a possible variation cause with PR interval? Correct ans -
Disturbance in conduction usually in the AV node, bundle of his, or bundle
branches but can be atria as well.
10. What does the QRS interval represent? Correct ans -
Measure from beginning to end of QRS complex, represent time taken for d
epolarization (contraction) of both ventricles (systole).
11. What is the normal QRS interval? Correct ans - <0.12.
This study source was downloaded by 100000894421506 from CourseHero.com on 01-17-2025 19:29:01 GMT -
https://www.coursehero.com/file/226008289/Cardiac-Dysrhythmias-Advanceddocx/
, 12. What is a possible variation cause with the QRS interval? Correct ans -
Disturbance in conduction in the bundle branches or in the ventricles.
13. What does the ST Segment represent? Correct ans -
Measure from the S wave of the QRS complex to the beginning of the T wave;
represents time between ventricular depolarization and repolarization (Diastole);
should be isoelectric (flat).
14. What is the normal ST segment? Correct ans - 0.12.
15. What is a possible variation cause with the ST segment? Correct ans -
Disturbance usually caused by ischemia, injury or infarction.
16. What does the T wave represent? Correct ans -
Represents time for ventricular repolarization, should be upright.
17. What is the normal T wave? Correct ans - 0.16.
18. What is a possible variation cause for a T wave? Correct ans -
Disturbance usually caused by electrolyte disturbances; ischemia or i
nfarction.
19. What does the QT interval represent? Correct ans -
Measured from beginning of the QRS to end of the T wave, represents time t
aken for entire electrical depolarization and repolarization of the ventricles.
20. What is the normal QT interval? Correct ans - 0.34 - 0.43.
21. What is the possible variation cause for a QT interval? Correct ans -
Disturbance usually affected repolarization more than depolarization and ca
use by drugs, electrolyte imbalances, and change in hr.
22. What is the normal firing of the SA Node? Correct ans - 60 -
100 times/min.
23. What is the normal firing of the AV Node? Correct ans - 40 -
60 times/min.
24. What is the normal firing of the Bundle of HIS/Purkinje Fibers?
Correct
ans - 20 -
40 times/min.
25. What are the characteristics of Normal Sinus Rhythm? Correct ans -
60 - 100 bpm, regular, normal P wave/PR and QRS.
This study source was downloaded by 100000894421506 from CourseHero.com on 01-17-2025 19:29:01 GMT -
https://www.coursehero.com/file/226008289/Cardiac-Dysrhythmias-Advanceddocx/
