Deck 10: Post-Test

Question 1

In the limb leads,the ST-segment is normally isoelectric.

Answer 1

True
,extends from the end of the S wave,and curves gradually upward to the beginning of the T wave.In the limb leads,the normal ST segment is isoelectric (flat),but may normally be slightly elevated or depressed.

Question 2

Depolarization is the same as contraction.

Answer 2

False
Depolarization is not the same as contraction.Depolarization is an electrical event that is expected to result in contraction,which is a mechanical event.It is possible to see organized electrical activity on the cardiac monitor,even when the assessment of the patient reveals no palpable pulse.This clinical situation is called pulseless electrical activity (PEA).

Question 3

The point where the QRS complex and ST segment meet is called the ST junction or the J point.

Answer 3

True
The point where the QRS complex and the ST segment meet is called the ST junction or the J point.The ST segment is considered elevated if the segment is deviated above the baseline and is considered depressed if the segment deviates below it.

Question 4

Proper positioning of the electrodes for leads I,II,and III requires placement on the patient's torso.

Question 5

The term acute coronary syndromes refers to patients presenting with ischemic chest pain.

Question 6

Cardiac output is the amount of blood pumped into the aorta each minute by the heart.

Question 7

The term ectopic refers to an extra muscle bundle consisting of working myocardial tissue that forms a connection between the atria and ventricles outside the normal conduction system.

Question 8

A macroreentrant circuit is one that involves a small area of heart tissue,usually a few centimeters or less.

Question 9

The left atrium receives blood from the _____.

A) aorta
B) pulmonary veins
C) pulmonary arteries
D) inferior vena cava

Question 10

Two conditions must exist to suspect bundle branch block.First,the QRS complex must have an abnormal duration (0.12 seconds or more in width),and second _____.

A) an RSR' complex must be seen in leads V1-V6
B) a QS pattern must be seen in leads I,II,and III
C) a slurred upstroke of the QRS complex must exist
D) the QRS complex must arise as the result of supraventricular activity

Question 11

The inferior surface of the left ventricle is supplied by the _____ coronary artery in most of the population.

A) left
B) right

Question 12

A Q wave,if present,is always a negative waveform.

Question 13

Individuals with preexcitation syndrome are predisposed to tachydysrhythmias.

Question 14

A delay or block that occurs in one of the bundle branches affects ventricular depolarization.

Question 15

Which of the following correctly reflects the ECG indicators of ischemia?

A) Pathologic Q waves,ST-segment elevation
B) ST-segment elevation,T wave inversion
C) ST-segment depression,T wave inversion
D) Pathologic Q waves,ST-segment depression

Question 16

The electrocardiogram (ECG)is a reflection of the heart's mechanical activity.

Question 17

The _____ originate from small mounds of myocardium called papillary muscles and serve as anchors to prevent the cusps of the AV valves from inverting into the atria.

A) Purkinje fibers
B) coronary sinuses
C) coronary arteries
D) chordae tendineae

Question 18

In most ECG leads,a normal Q wave is less than 0.04 seconds in duration and less than one-third of the amplitude of the R wave in that lead.

Question 19

The six limb leads view the heart in the frontal plane as if the body were flat.

Question 20

Leads V?R,V?R,and V?R are used to view the posterior wall of the left ventricle.

Question 21

The first segment of the left coronary artery is the _____ artery.

A) circumflex
B) right coronary
C) left main coronary
D) left anterior descending

Question 22

Where is the positive electrode placed in lead III?

A) Right arm
B) Left arm
C) Left leg or foot
D) Right leg or foot

Question 23

Tall,peaked T waves observed on the ECG are most commonly seen in patients with _____.

A) hypokalemia
B) hyponatremia
C) hyperkalemia
D) hypernatremia

Question 24

Atrial fibrillation is characterized by _____.

A) an erratic,wavy baseline and irregular ventricular rhythm
B) "saw-tooth"- or "picket-fence"-shaped waveforms preceding each QRS
C) one P wave before each QRS and a regular ventricular rate of 60 to 100 beats/min
D) P waves occurring before,during,or after the QRS complex; when seen,they are inverted

Question 25

The myocardium is thickest in the ____.

A) left atrium
B) right atrium
C) left ventricle
D) right ventricle

Question 26

Which of the following are chest leads?

A) Leads I,II,and III
B) Leads I and aVL
C) Leads V1,V2,V3,V4,V5,and V6
D) Leads I,II,III,aVR,aVL,and aVF

Question 27

How are frequent PACs usually managed?

A) Defibrillation
B) Synchronized cardioversion
C) Correcting the underlying cause
D) Administration of medications such as atropine or epinephrine

Question 28

In an adult,the normal duration of the QRS complex is _____ seconds.

A) 0.12 to 0.20
B) 0.06 to 0.11
C) 0.04 to 0.14
D) 0.20 to 0.38

Question 29

Which of the following leads are anatomically contiguous?

A) II,V2
B) II,III,V3
C) I,V3,V4
D) V2,V3,V4

Question 30

A delta wave is an ECG characteristic associated with which of the following dysrhythmias?

A) Junctional rhythm
B) AV nodal reentrant tachycardia (AVNRT)
C) Wolff-Parkinson-White (WPW)syndrome
D) Accelerated idioventricular rhythm (AIVR)

Question 31

Which of the following correctly describes multifocal atrial tachycardia?

A) The atrial rhythm is regular.
B) The ventricular rhythm is irregular.
C) The atrial and ventricular rhythms are regular.
D) The atrial and ventricular rhythms are irregular.

Question 32

Anterior wall myocardial infarctions are most often a result of an occlusion of a branch of the _____ coronary artery.

A) left
B) right

Question 33

Which of the following are chest leads?

A) Leads I and aVL
B) Leads I,II,and III
C) Leads V1,V2,V3,V4,V5,V6
D) Leads I,II,III,aVR,aVL,and aVF

Question 34

Signs and symptoms experienced during a tachydysrhythmia are usually primarily related to _____.

A) atrial irritability
B) vasoconstriction
C) slowed conduction through the AV node
D) decreased ventricular filling time and stroke volume

Question 35

The anterior surface of the heart consists primarily of the _____.

A) left atrium
B) right atrium
C) left ventricle
D) right ventricle

Question 36

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

Question 37

Which side of the heart is a high-pressure system that pumps arterial blood to the systemic circulation?

A) Left
B) Right

Question 38

In a junctional rhythm viewed in lead II,where is the location of the P wave on the ECG if ventricular depolarization precedes atrial depolarization?

A) Before the QRS complex
B) During the QRS complex
C) After the QRS complex

Question 39

_____ is a term used to describe the period of recovery that cells need after being discharged before they are able to respond to a stimulus.

A) Irritability
B) Polarization
C) Conductivity
D) Refractoriness

Question 40

An ECG machine's sensitivity must be calibrated so that a 1-mV electrical signal will produce a deflection measuring exactly _____-mm tall.

A) 0.5
B) 1
C) 5
D) 10

Question 41

An accessory pathway that has one end attached to normal conductive tissue is called a(n)_____ _____.

Question 42

Myocardial ischemia delays the process of repolarization; therefore the ECG changes characteristic of ischemia include _____.

A) widening of the QRS complex
B) prolongation of the PR interval
C) changes in the ST segment and T wave
D) changes in the QRS complex and ST segment

Question 43

If the AV junction paces the heart,the electrical impulse must travel in a backward direction to activate the atria.This is called _____ conduction.

Question 44

A(n)_____ _____ occurs as a result of an electrical impulse from a supraventricular site (such as the SA node)discharging at the same time as an ectopic site in the ventricles.

Question 45

A _____ bundle branch block produces a QS pattern in lead V?.

Question 46

The axes of leads I,II,and III form an equilateral triangle with the heart at the center (Einthoven's triangle).If the augmented limb leads are added to this configuration and the axes of the six leads moved in a way in which they bisect each other,the result is the _____ _____ _____.

Question 47

Sometimes,when a premature atrial complex (PAC)occurs very prematurely and close to the T wave of the preceding beat,only a P wave may be seen with no QRS after it (appearing as a pause).This type of PAC is termed a(n)_____ PAC.

Question 48

The right atrium receives deoxygenated blood from the _____ _____ _____ (which carries blood from the head and upper extremities),the _____ _____ _____ (which carries blood from the lower body),and the _____ _____ (which receives blood from the intracardiac circulation).

Question 49

Each small box on ECG paper represents _____ seconds.

Question 50

A(n)_____ _____ is a vertical line on the ECG that indicates the pacemaker has discharged.

Question 51

Describe the appearance of a pathologic Q wave.

Question 52

Indicate the heart surface viewed by each of the following:

Question 53

Lead III views the _____ wall of the left ventricle.

A) septal
B) inferior
C) posterior
D) lateral

Question 54

Complete the following:

Question 55

A QRS measuring 0.10 to 0.12 seconds is called a(n)_____ right or left bundle branch block.

Question 56

Explain the difference between a PVC and a ventricular escape beat.

Question 57

Indicate the inherent rates for each of the following pacemaker sites:

Question 58

A beat originating from the AV junction that appears later than the next expected sinus beat is called a(n)_____ _____ _____.

Question 59

The area supplied by an obstructed coronary artery goes through a characteristic sequence of events that have been identified as zones of _____,_____,and _____.

Question 60

When reviewing a 12-lead ECG,intervals and duration are usually expressed in _____.

Question 61

Your patient has a VVI pacemaker.Briefly explain the meaning of each of these letters.

Question 62

Explain the meaning of the letters in aVR,aVL,and aVF.

Question 63

List five signs or symptoms of decreased cardiac output.

Question 64

When is the term intraventricular conduction delay used?

Question 65

Explain the benefits of a dual-chamber pacemaker.

Question 66

What is a biphasic waveform?