CARDIAC - Test Bank Questions
Chapter 11 >>>
Which of the following structures is the primary pacemaker of the heart?
a.
Ventricular tissue
c.
Sinoatrial node
b.
Atrioventricular node
d.
Purkinje fibers >>> ANS: C
With an intrinsic rate of 60 to 100 beats/min, the sinoatrial node is the primary pacemaker in a healthy
heart. The atrioventricular node beats 40 to 60 beats/min. Ventricular tissue must have an electrical
impulse to contract. Purkinje fibers beat 15 to 40 beats/min
3. Why do many patients with very high heart rates frequently have chest pain and shortness of breath?
a.
Patients with heart disease frequently have an anxiety disorder as well.
b.
The rapid pounding of the heart in the chest wall causes the physical pain.
c.
The heart muscle gets tired from the increased work.
d.
The decreased diastolic time decreases oxygen delivery to the myocardium. >>> ANS: D
The coronary arteries are perfused during diastole. When the heart rate increases, the diastolic time
decreases as each contraction has less time to be completed. This decreases the time the coronary
,arteries have to deliver oxygenated blood to the myocardium. The symptoms described are caused by a
lack of oxygen in the myocardium.
4. A patient reports feeling dizzy after standing quickly. Which of the following could provide a clue
regarding the cause?
a.
Hemoglobin level of 14.0 g/dL and hematocrit level of 42.3%
b.
Poor skin turgor with extended tenting
c.
Supine blood pressure of 146/93 mm Hg
d.
Resting heart rate of 96 beats/min >>> ANS: B
Poor skin turgor could suggest dehydration. Dehydration can cause orthostatic hypotension because of
low capacitance reserves from hypovolemia. Supine blood pressure of 146/93 mm Hg would be
considered hypertensive, and the patient would most likely experience a headache rather than
dizziness. A resting heart rate of 96 beats/min is still considered a normal value.
5. A patient presents with atrial fibrillation, a heart rate of 156 beats/min, and a blood pressure of
124/76 mm Hg. The physician orders diltiazem, a calcium channel blocker, to be given slowly by
intravenous push. Why did the physician choose this medication to treat this patient's atrial
tachyarrhythmia?
a.
Diltiazem decreases the calcium influx into the AV nodal tissue and decreases the speed of impulse
conduction.
b.
Diltiazem increases the calcium influx into the AV nodal tissue and decreases the speed of impulse
conduction.
c.
Diltiazem decreases the calcium influx into the myocardial tissue and decreases the strength of heart
contraction.
d.
,Diltiazem increases the calcium influx into the myocardial tissue and decreases the strength of heart
contraction. >>> ANS: A
Calcium channel-blocking drugs, such as verapamil and diltiazem, inhibit the inward Ca++ current into
pacemaker tissue, especially the AV node. For this reason, they are used therapeutically to slow the rate
of atrial tachydysrhythmias and protect the ventricle from excessive atrial impulses.
6. The hemodynamic effects of a pericardial effusion include
a.
increased ventricular ejection.
c.
myocardial ischemia.
b.
decreased ventricular filling.
d.
increased afterload. >>> ANS: B
If the fluid collection in the sac (pericardial effusion) impinges on ventricular filling, ventricular ejection,
or coronary artery perfusion, a clinical emergency may exist that necessitates removal of the excess
pericardial fluid to restore normal cardiac function. Myocardial ischemia is damage of the myocardium
muscle as the result of a heart attack.
7. The contribution of atrial kick to ventricular filling is approximately
a.
10%.
c.
5%.
b.
20%.
d.
45%. >>> ANS: B
, Atrial contraction, also known as "atrial kick," contributes approximately 20% of blood flow to
ventricular filling; the other 80% occurs passively during diastole.
8. The function of the AV valves is to
a.
prevent backflow of blood into the atria during ventricular contraction.
b.
prevent blood regurgitation back into the ventricles.
c.
assist with blood flow to the lungs and aorta.
d.
contribute to ventricular filling by atrial kick. >>> ANS: A
The AV valves are open during ventricular diastole (filling) and prevent backflow of blood into the atria
during ventricular systole (contraction). Semilunar valves prevent the backflow of pulmonic and aortic
blood back into the ventricles.
9. Which step of impulse conduction is most conducive to atrial kick?
a.
The firing of the sinoatrial node, which results in atrial depolarization
b.
The conduction delay at the AV node, allowing time for filling
c.
Conduction through the bundle of His, enhancing ventricular depolarization
d.
Conduction to the Purkinje fibers, allowing for ventricular contraction >>> ANS: B
The conduction delay at the AV node allows adequate time for ventricular filling from atrial contraction.
10. Which of the following is an example of a physiologic shunt?
a.
A ventricular septal defect
Chapter 11 >>>
Which of the following structures is the primary pacemaker of the heart?
a.
Ventricular tissue
c.
Sinoatrial node
b.
Atrioventricular node
d.
Purkinje fibers >>> ANS: C
With an intrinsic rate of 60 to 100 beats/min, the sinoatrial node is the primary pacemaker in a healthy
heart. The atrioventricular node beats 40 to 60 beats/min. Ventricular tissue must have an electrical
impulse to contract. Purkinje fibers beat 15 to 40 beats/min
3. Why do many patients with very high heart rates frequently have chest pain and shortness of breath?
a.
Patients with heart disease frequently have an anxiety disorder as well.
b.
The rapid pounding of the heart in the chest wall causes the physical pain.
c.
The heart muscle gets tired from the increased work.
d.
The decreased diastolic time decreases oxygen delivery to the myocardium. >>> ANS: D
The coronary arteries are perfused during diastole. When the heart rate increases, the diastolic time
decreases as each contraction has less time to be completed. This decreases the time the coronary
,arteries have to deliver oxygenated blood to the myocardium. The symptoms described are caused by a
lack of oxygen in the myocardium.
4. A patient reports feeling dizzy after standing quickly. Which of the following could provide a clue
regarding the cause?
a.
Hemoglobin level of 14.0 g/dL and hematocrit level of 42.3%
b.
Poor skin turgor with extended tenting
c.
Supine blood pressure of 146/93 mm Hg
d.
Resting heart rate of 96 beats/min >>> ANS: B
Poor skin turgor could suggest dehydration. Dehydration can cause orthostatic hypotension because of
low capacitance reserves from hypovolemia. Supine blood pressure of 146/93 mm Hg would be
considered hypertensive, and the patient would most likely experience a headache rather than
dizziness. A resting heart rate of 96 beats/min is still considered a normal value.
5. A patient presents with atrial fibrillation, a heart rate of 156 beats/min, and a blood pressure of
124/76 mm Hg. The physician orders diltiazem, a calcium channel blocker, to be given slowly by
intravenous push. Why did the physician choose this medication to treat this patient's atrial
tachyarrhythmia?
a.
Diltiazem decreases the calcium influx into the AV nodal tissue and decreases the speed of impulse
conduction.
b.
Diltiazem increases the calcium influx into the AV nodal tissue and decreases the speed of impulse
conduction.
c.
Diltiazem decreases the calcium influx into the myocardial tissue and decreases the strength of heart
contraction.
d.
,Diltiazem increases the calcium influx into the myocardial tissue and decreases the strength of heart
contraction. >>> ANS: A
Calcium channel-blocking drugs, such as verapamil and diltiazem, inhibit the inward Ca++ current into
pacemaker tissue, especially the AV node. For this reason, they are used therapeutically to slow the rate
of atrial tachydysrhythmias and protect the ventricle from excessive atrial impulses.
6. The hemodynamic effects of a pericardial effusion include
a.
increased ventricular ejection.
c.
myocardial ischemia.
b.
decreased ventricular filling.
d.
increased afterload. >>> ANS: B
If the fluid collection in the sac (pericardial effusion) impinges on ventricular filling, ventricular ejection,
or coronary artery perfusion, a clinical emergency may exist that necessitates removal of the excess
pericardial fluid to restore normal cardiac function. Myocardial ischemia is damage of the myocardium
muscle as the result of a heart attack.
7. The contribution of atrial kick to ventricular filling is approximately
a.
10%.
c.
5%.
b.
20%.
d.
45%. >>> ANS: B
, Atrial contraction, also known as "atrial kick," contributes approximately 20% of blood flow to
ventricular filling; the other 80% occurs passively during diastole.
8. The function of the AV valves is to
a.
prevent backflow of blood into the atria during ventricular contraction.
b.
prevent blood regurgitation back into the ventricles.
c.
assist with blood flow to the lungs and aorta.
d.
contribute to ventricular filling by atrial kick. >>> ANS: A
The AV valves are open during ventricular diastole (filling) and prevent backflow of blood into the atria
during ventricular systole (contraction). Semilunar valves prevent the backflow of pulmonic and aortic
blood back into the ventricles.
9. Which step of impulse conduction is most conducive to atrial kick?
a.
The firing of the sinoatrial node, which results in atrial depolarization
b.
The conduction delay at the AV node, allowing time for filling
c.
Conduction through the bundle of His, enhancing ventricular depolarization
d.
Conduction to the Purkinje fibers, allowing for ventricular contraction >>> ANS: B
The conduction delay at the AV node allows adequate time for ventricular filling from atrial contraction.
10. Which of the following is an example of a physiologic shunt?
a.
A ventricular septal defect
