Wilkins Clinical Assessment In Respiratory Care 7th Edition By Heuer – Test Bank

Chapter 11: Interpretation of Electrocardiogram Tracings
Test Bank

MULTIPLE CHOICE

1. Why is it important for a respiratory therapist (RT) to be able to identify cardiac dysrhythmias?
a. It is likely that the RT will observe the onset of the initial event
b. The RT is primarily responsible for management of the dysrhythmia.
c. The RT must be able to confirm the physician’s initial diagnosis.
d. RTs are always the first responders for complaints of a cardiac nature.

ANS: A
Given the hands-on nature of respiratory care, the likelihood that an RT may observe a patient during the acute onset of an ischemic cardiac event or a lethal dysrhythmia is high. Thus, it is vital for RTs to have basic knowledge in electrocardiogram (ECG) interpretation.

REF: pg. 235 OBJ: 1

2. Why is an ECG tracing so useful?
a. It reflects the heart’s pumping ability.
b. It can identify structural abnormalities in the heart.
c. It can be used to diagnose malfunctioning valves.
d. It can aid in the diagnosis of cardiac tissue ischemia.

ANS: D
If a patient presents with dyspnea and chest discomfort, an ECG can aid in the diagnosis of an ischemic cardiac event. It is important to note that the ECG tracing does not measure the pumping ability of the heart. It is not unusual for a patient with low cardiac output to have a normal ECG tracing. This is because the ECG does not directly depict abnormalities in cardiac structure such as defects in the heart valves or the interventricular septum.

REF: pg. 235 OBJ: 1 | 2

3. Which of the following symptoms is least suggestive of the need for an ECG?
a. Fever
b. Orthopnea
c. Chest pain
d. Fainting spells

ANS: A
Orthopnea, chest pain, and fainting spells all are clinical findings that suggest the need for an ECG; fever is not (see Box 11-1, pg. 236).

REF: pg. 236 OBJ: 3

4. Which chamber of the heart initially receives deoxygenated blood from the vena cava?
a. Left atrium
b. Left ventricle
c. Right atrium
d. Right ventricle

ANS: C
The right atrium receives deoxygenated blood from the vena cava and directs the blood into the right ventricle.

REF: pg. 236 OBJ: 3

5. Which chamber is responsible for pumping blood into the pulmonary circulation?
a. Left atrium
b. Left ventricle
c. Right atrium
d. Right ventricle

ANS: D
Right ventricular contraction ejects blood into the pulmonary artery, which carries blood to the lungs for oxygenation.

REF: pg. 236 OBJ: 3

6. Which chamber normally has the largest muscle mass?
a. Left atrium
b. Left ventricle
c. Right atrium
d. Right ventricle

ANS: B
Because the left side of the heart pumps blood throughout the entire body, it normally has a significantly larger muscle mass than the right side.

REF: pg. 236 OBJ: 3

7. Where does the normal electrical impulse originate for each heartbeat?
a. Atrioventricular (AV) node
b. Sinoatrial (SA) node
c. Bundle of His
d. Right bundle branch

ANS: B
Normally, the electrical activity of the heart is initiated in the sinus or sinoatrial (SA) node, which is located in the right atrium (see Figure 11-2, pg. 236).

REF: pg. 236 OBJ: 5

8. What term describes heart cells that have the ability to spontaneously depolarize?
a. Systole
b. Purkinje
c. Automaticity
d. Myocardiocity

ANS: C
Cells that have the ability to generate electrical activity spontaneously are said to exhibit automaticity.

REF: pg. 236 OBJ: 5

9. Why is the electrical signal delayed slightly at the AV node?
1. To allow better filling of the ventricles
2. To protect the ventricles against excessively rapid atrial rates
3. To provide time for atrial contraction prior to ventricular systole
4. To prevent premature atrial beats from reaching the ventricles
a. 1, 3
b. 2, 4
c. 1, 2
d. 1, 2, 3, 4

ANS: C
Once the electrical impulse reaches the AV node, it is delayed for approximately 0.1 second before it passes on into the bundle of His. The delay is believed to serve the purpose of allowing more complete filling of the ventricles before ventricular contraction, which occurs as the result of atrial contraction. In addition, the AV node can protect the ventricles from excessively rapid atrial rates that the ventricles could not tolerate.

REF: pg. 237 OBJ: 5

10. What is the ventricular heart rate when the AV node paces the heart?
a. 20 to 40 beats/min
b. 40 to 60 beats/min
c. 60 to 80 beats/min
d. 80 to 100 beats/min

ANS: B
If the SA node fails to function properly and does not pace the heart, the AV junction can serve as the pacemaker for the ventricles. When this occurs, the ventricular rate is usually between 40 and 60 beats/min and the ECG reveals a distinct pattern, as is described later in this chapter (see Figure 11-3, pg. 237).

REF: pg. 237 OBJ: 5