Deck 12: Electrocardiogram Identification

Question 1

What is the normal spontaneous depolarization of the SA node?

A) 60 to 100 beats/min
B) 80 to 100 beats/min
C) 60 to 120 beats/min
D) 80 to 120 beats/min

Answer 1

A
An uninhibited SA node will spontaneously depolarize 60 to 100 times per minute.For a rhythm coming from the SA node to be considered normal,sinus rhythm must fall within this range.

Question 2

Which of the following causes the absolute refractory period during depolarization?

A) An influx of Ca²⁺ ions
B) An influx of Na⁺ ions
C) The lack of an ion gradient for potential discharge
D) The increased ion gradient

Answer 2

C
For an action potential to be generated,there must exist an ion gradient on both side of a membrane.A relative balance on either side of a membrane will not allow a rush of ions to flow from one side of a membrane to the other when channels are opened.

Question 3

A premature ventricular contraction (PVC)may occur at regular intervals in an established pattern.Which of the following is the result of this occurring every other beat?

A) Bigeminy
B) Trigeminy
C) Quadrigeminy
D) Couplet

Answer 3

A
Bigeminy occurs every second beat,trigeminy occurs every third beat,and quadrigeminy occurs every fourth beat.A couplet occurs when two PVC happen in a row.

Question 4

Where do supraventricular dysrhythmias occur?

A) At the level of the SA node
B) Above the level of the atria
C) Above the level of the ventricles
D) At the level of the AV node

Question 5

An impulse originating from an ectopic focus in the ventricles that is outside of the normal conduction pathway has which of the following characteristics?
A) All of the above

A) Slower propagation because of the syncytial arrangement of the myocardial cells
B) Uncoordinated contraction
C) Decrease in ejection of blood volume

Question 6

Which of the following causes the plateau phase during repolarization?

A) Outward flow of K⁺ ions is balanced by an inward flow of Ca²⁺ ions.
B) Influx of Na⁺ ions is much slower than Ca²⁺ ions.
C) K⁺ pumps are inactive after depolarization.
D) The amount of Na⁺ ions on both sides of the membrane are balanced at this point of the action potential.

Question 7

How can a ventricular dysrhythmia be differentiated from a supraventricular dysrhythmia?

A) Taking the patient's heart rate.
B) The length of the QRS segment
C) The presence of an ectopic focus in the atria
D) The absence of QRS complex

Question 8

Ventricular tachycardia and ventricular fibrillation may present the same with the exception of which of the following?

A) All complexes are ventricular in origin.
B) The patient may be asymptomatic.
C) Effective circulation is not preserved.
D) There may be an immediate loss of consciousness.

Question 9

What is the normal timing of the P-R interval?

A) 0.01 seconds
B) 0.12 to 0.2 seconds
C) >0.2 seconds
D) <0.1 seconds

Question 10

Which heart conduction block is characterized by a longer P-R interval (>0.2 sec)?

A) Sinus block
B) First degree
C) Second degree
D) Third degree

Question 11

What is the definition of a narrow-complex tachycardia?

A) Supraventricular in origin and has a QRS complex <0.12 sec
B) Ventricular in origin and ha a QRS complex <0.12 sec
C) Supraventricular in origin and has a QRS complex >0.12 sec
D) Ventricular in origin and has a QRS complex > 0.12 sec

Question 12

An ECG that shows both positive and negative deflections of the QRS complex from the baseline would be likely showing:

A) PVCs occurring at regular intervals.
B) bigeminy.
C) a multifocal PVC.
D) disruption of the P wave.

Question 13

A premature junctional complex (PJC)has which of the following characteristics?

A) An ectopic focus in the atria causing spontaneous depolarization
B) A run of P waves preceded by a QRS complex
C) A later and later appearance of the R wave
D) No associated P wave or one that is inverted followed or preceded by a QRS complex

Question 14

When considering a third-degree heart block,which of the following is true?

A) Third-degree block is considered an incomplete heart block.
B) Third-degree block has a 1:1 ratio of P wave to QRS complexes.
C) Third-degree block have a progressively longer P-R interval until a P wave is fails to conduct to the ventricles.
D) Third-degree block is treated with implantation of a pacemaker.

Question 15

With regard to a patient's readiness for activity or participation in a cardiac rehabilitation program,which of the following does not need to be able to be answered by the rehabilitation professional?

A) Recognition of heart rhythms and their associated variations
B) Implications of a rhythms systemic and hemodynamic effects
C) Benign heart rhythms
D) All of the above

Question 16

In the absence of an atrial pulse,which of the following would normally happen?

A) The heart rate would slow because of the presence of the junctional rhythm.
B) The myocardium would have increased metabolic demand because of the increase in heart rate.
C) The QRS complex is preceded by a P wave.
D) The QRS complex is absent.

Question 17

What is the 10th electrode on a standard 12 lead ECG is used for?

A) To monitor the frontal plane
B) To monitor the transverse plane
C) To monitor the sagittal plane
D) To stabilize the baseline

Question 18

Where does an ectopic focus originate?

A) A beat or rhythm that originates in the SA node
B) A beat or rhythm that does not originate in the SA node
C) A beat or rhythm that originates in the AV node
D) A beat or rhythm that does not originate in the AV node

Question 19

The QRS complex occurs within which time frame listed below?

A) 0.01 to 012 seconds
B) 0.02 to 0.1 seconds
C) 0.04 to 0.016 seconds
D) 0.04 to 0.12 seconds

Question 20

Sinus tachycardia and sinus bradycardia are both rhythms that have systemic affects.Which of the following are complications of tachycardia?

A) Increase O₂ demand, ischemia exacerbation of the heart, and increased workload on the heart
B) Syncope, increased O₂ demand, and reduction in cardiac output
C) Lightheadedness, decreased O₂ demand, and heart rate less than 60 beats/min
D) Heart rate greater than 100 beats/min, syncope, and reduced cardiac output