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30 Cards in this Set
- Front
- Back
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The period of time during the cardiac cycle when cells cannot respond to a stimulus, no matter how strong, is called the relative refractory period.
A) True B) False |
False
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Depolarization is the same as contraction.
A) True B) False |
False
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In most ECG leads, a normal Q wave is less than 0.04 seconds in duration and less than 1/3 of the amplitude of the R wave in that lead.
A) True B) False |
True
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The point where the QRS complex and ST-segment meet is called the "junction" or "J" point.
A) True B) False |
True
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If the wave of depolarization (electrical impulse) moves toward the positive electrode, the waveform recorded on ECG graph paper will be upright (positive deflection).
A) True B) False |
True
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The PR interval is considered prolonged if it is more than _____ seconds in duration.
A) 0.06 sec B) 0.12 sec C) 0.18 sec D) 0.20 sec |
D) 0.20 Sec
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What is the significance of a PR interval measuring less than 0.12 or more than 0.20 seconds?
A) The patient is likely to have a history of sick sinus syndrome. B) The impulse followed an abnormal pathway or was delayed in the area of the AV node. C) A complete (third-degree) AV block must be present. D) The patient is experiencing myocardial ischemia or infarction. |
B) The impulse followed an abnormal pathway or was delayed in the area of the AV node.
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How do you determine whether the atrial rhythm on an ECG tracing is regular or irregular?
A) Compare QT intervals. B) Compare PR intervals. C) Compare P to P intervals. D) Compare R to R intervals. |
C) Compare P to P intervals.
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__________ is the ability of cardiac pacemaker cells to spontaneously initiate an electrical impulse without being stimulated from another source (such as a nerve).
A) Excitability B) Automaticity C) Conductivity D) Contractility |
B) Automaticity
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In the heart's conduction system, the _____ receive(s) an electrical impulse from the bundle of His and relay(s) it to the Purkinje fibers in the ventricular myocardium.
A) Right and left bundle branches B) Sinoatrial (SA) node C) Atrioventricular (AV) node D) AV junction |
A) Right and left bundle branches
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In the heart's conduction system, the _____ receive(s) an electrical impulse from the SA node and delays relay of the impulse to the bundle of His..
A) Atrial pacemaker cells B) AV node C) Purkinje fibers D) Right and left bundle branches |
B) AV node
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The ECG does not provide information about:
A) The presence of ischemic damage. B) Conduction disturbances. C) Electrical effects of medications and electrolytes. D) The mechanical (contractile) condition of the myocardium. |
D) The mechanical (contractile) condition of the myocardium.
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What does the QRS complex represent?
A) Atrial depolarization B) Ventricular depolarization C) Ventricular contraction D) Ventricular repolarization |
B) Ventricular depolarization
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The normal pacemaker of the heart is the _____, which is found in the _____.
A) SA node; left atrium B) SA node; right atrium C) AV node; left atrium D) AV node; right atrium |
B) SA node; right atrium
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On an ECG, what is the first negative deflection seen after the P wave?
A) Q wave B) R wave C) S wave D) T wave |
A) Q wave
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Where is the negative electrode placed in lead II?
A) Right arm B) Right leg C) Left arm D) Left leg |
A) Right arm
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On the ECG, the T wave represents:
A) Atrial depolarization. B) Atrial repolarization. C) Ventricular depolarization. D) Ventricular repolarization. |
D) Ventricular repolarization.
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Select the incorrect statement regarding the PR interval.
A) A normal PR interval measures 0.12 to 0.20 seconds. B) The PR interval normally lengthens as the heart rate increases. C) The PR interval is measured from the point where the P wave leaves the baseline to the beginning of the QRS complex. D) A normal PR interval indicates the electrical impulse was conducted normally through the heart's conduction system. |
B) The PR interval normally lengthens as the heart rate increases.
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In most adults, a normal PR interval is _____ in duration.
A) 0.04 to 0.06 seconds B) 0.06 to 0.12 seconds C) 0.12 to 0.20 seconds D) 0.16 to 0.24 seconds |
C) 0.12 to 0.20 seconds
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The portion of the ECG tracing between the QRS complex and the T wave is called the:
A) PR segment. B) ST-segment. C) QT interval. D) PR interval. |
B) ST-segment.
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On the ECG, the P wave represents atrial _____ and the QRS complex represents ventricular _____.
A) Depolarization; depolarization B) Depolarization; repolarization C) Repolarization; depolarization D) Repolarization; repolarization |
A) Depolarization; depolarization
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_____ is a term used to describe the extent to which a cell is able to respond to a stimulus.
A) Inotropy B) Chronotropy C) Polarization D) Refractoriness |
D) Refractoriness
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Which of the following are chest leads?
A) Leads I, II, and III B) Leads aVR, aVL, and aVF C) Leads V1, V2, V3, V4, V5, and V6 D) Leads I, II, III, aVR, aVL, and aVF |
C) Leads V1, V2, V3, V4, V5, and V6
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The ST-segment is measured from:
A) The end of the QRS complex to the beginning of the T wave. B) The end of the QRS complex to the end of the T wave. C) The beginning of the QRS complex to the end of the T wave. D) The beginning of the QRS complex to the beginning of the T wave. |
A) The end of the QRS complex to the beginning of the T wave.
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Tall, peaked T waves observed on the ECG are most commonly seen in patients with:
A) Hyponatremia. B) Hypernatremia. C) Hypokalemia. D) Hyperkalemia. |
D) Hyperkalemia.
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Which of the following ECG leads view the heart in the horizontal plane, allowing a view of the front and left side of the heart?
A) V1, V2, V3, aVL, aVF, and lead I B) Leads I, II, III, aVR, aVL, and aVF C) V1, V2, V3, V4, V5, and V6 D) Leads I, II, III, V4, V5, and V6 |
C) V1, V2, V3, V4, V5, and V6
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In Lead II, the positive electrode is located on the:
A) Left arm. B) Left leg. C) Right arm. D) Right leg. |
B) Left leg.
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Chest leads are sometimes called precordial or “V” leads.
A) True B) False |
A) True
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Excitability refers to the ability of cardiac muscle cells to respond to an external stimulus, such as that from a chemical, mechanical, or electrical source.
A) True B) False |
A) True
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A conduction problem above the level of the bundle branches will largely affect the P wave and PR interval.
A) True B) False |
A) True
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