CCRN Practice Questions with verified
answers- Cardiovascular
A patient is in cardiac and respiratory arrest. The selection of medications to reestablish cardiac
t t t t t t t t t t t t t t
function would stimulate the sympathetic nervous system beta1 receptors. This stimulation
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would result in increased automaticity and which of the
t t t t t t t t t
following?
a. Increased myocardial contractility
t t t
b. Decreased left ventricular stroke work
t t t t t
c. Decreased myocardial oxygen consumption
t t t t
d. Increased left ventricular afterload - ➡ Correct answer: a
t t t t t t t t t
Rationale: The sympathetic nervous system contains alpha, beta, and dopaminergic receptors
t t t t t t t t t t
that produce various responses when stimulated. Stimulation of beta1 receptors increases
t t t t t t t t t t t
heart rate, conductivity, and myocardial contractility. Stimulation of beta2 receptors produces
t t t t t t t t t t t
vasodilation and bronchodilation. Alpha receptors, when stimulated,
t t t t t t t
produce vasoconstriction. Stimulation of dopaminergic receptors produces a vasodilating
t t t t t t t t
effect on renal, mesenteric, coronary, and cerebral vessels.
t t t t t t t
Test-Taking Strategy: Note the helpful clue in the stem: stimulate the sympathetic system and
t t t t t t t t t t t t t
recall that this results in a fight-or-flight response—the body is responding to survive. Stroke
t t t t t t t t t t t t t t
volume would increase, so eliminate option b. Afterload would increase, but this is due to alpha
t t t t t t t t t t t t t t t t
stimulation, not beta1 stimulation, so eliminate option d. Because the heart is working faster
t t t t t t t t t t t t t t
and harder, the myocardial oxygen consumption does increase, so eliminate option c.
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Remember that the primary effects of beta1 receptors are to increase heart rate, contractility,
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and rate of conduction. Choose option a. A memory aid that also may help is this: beta 1 beta 2, 1
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heart 2 lungs: beta1 affects the heart, and beta2 affects the lungs.
t t t t t t t t t t t t
A patient arrived in the emergency department with complaints of chest pain. The 12-lead
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electrocardiogram shows ST segment elevation in leads V3 and V4. Occlusion of the affected
t t t t t t t t t t t t t t
coronary artery most likely would affect perfusion to which portion of the
t t t t t t t t t t t t
conduction system? t
a. Sinoatrial (SA) node
t t t
,b. Bachmann's bundle
t t
c. Atrioventricular (AV) node
t t t
d. Bundle of His - ➡ Correct answer: d
t t t t t t t t
Rationale: ST segment elevation in leads V3 and V4 indicates injury to the anterior wall, which
t t t t t t t t t t t t t t t
would occur with occlusion of the left anterior descending (LAD) artery. In most persons, the SA
t t t t t t t t t t t t t t t t
node, Bachmann's bundle, and AV node are supplied by the right coronary artery. The bundle of
t t t t t t t t t t t t t t t t
His is supplied by the left anterior descending artery. This is why an
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anterior myocardial infarction may cause type II second-degree AV block or third-degree AV
t t t t t t t t t t t t
heart block at the level of the bundle of His.
t t t t t t t t t t
Test-Taking Strategy: Note that options a, b, and c are part of the supraventricular conduction
t t t t t t t t t t t t t t
system. They usually are supplied by the right coronary artery. The LAD artery supplies most of
t t t t t t t t t t t t t t t t
the interventricular conduction system, including the bundle of His and
t t t t t t t t t t
the bundle branches.
t t
Oxygen delivery (DO2) is the product of which of the following?
t t t t t t t t t t
a. PaO2, hemoglobin, mean arterial pressure
t t t t t
b. SaO2, hemoglobin, cardiac output
t t t t
c. SvO2, cardiac index, SaO2
t t t t
d. PaO2, mean arterial pressure, SvO2 - ➡ Correct answer: b
t t t t t t t t t t
Rationale: Ninety-seven percent of oxygen is attached to the hemoglobin molecule, so the SaO2
t t t t t t t t t t t t t
(arterial oxygen saturation) is a more accurate reflection of the amount of oxygen in blood. The
t t t t t t t t t t t t t t t t
PaO2 represents only the 3% that is dissolved in the plasma. The lungs must put the oxygen in
t t t t t t t t t t t t t t t t t t
the blood, the hemoglobin must carry the oxygen, and the cardiac output is a reflection of how
t t t t t t t t t t t t t t t t t
well the heart is moving the blood with its hemoglobin with attached
t t t t t t t t t t t t
oxygen. SvO2 (venous oxygen saturation) is a reflection of the oxygen reserve. SvO2 is what is
t t t t t t t t t t t t t t t
left over after the tissues have extracted what they need. The mean arterial pressure is a
t t t t t t t t t t t t t t t t
reflection of organ tissue perfusion pressure but does not indicate anything about the amount
t t t t t t t t t t t t t t
of oxygen in that blood.
t t t t t
Test-Taking Strategy: Oxygen is delivered from the arterial end, so choose an option that has
t t t t t t t t t t t t t t
SaO2 instead of SvO2. Also remember that most oxygen is carried on hemoglobin. Look for SaO2
t t t t t t t t t t t t t t t t
(not PaO2) and hemoglobin. The only option with both of these is option b.
t t t t t t t t t t t t t t
, Which of the following types of block are most likely after an anterior wall myocardial infarction
t t t t t t t t t t t t t t t
(MI)?
t
a. Sinus block
t t
b. Second-degree atrioventricular (AV) block, type I
t t t t t t
c. Second-degree AV block, type II
t t t t t
d. Third-degree AV block with junctional escape rhythm - ➡ Correct answer: c
t t t t t t t t t t t t
Rationale: Anterior MI is caused by a left anterior descending (LAD) artery lesion. The LAD
t t t t t t t t t t t t t t
artery supplies the bundle of His and bundle branches, so anterior MIs may cause blocks of the
t t t t t t t t t t t t t t t t t
bundle of His or bundle branches. Second-degree AV block type II is a block at the level of the
t t t t t t t t t t t t t t t t t t t
bundle of His. If this patient does develop a third-degree AV block, it would be at the level of the
t t t t t t t t t t t t t t t t t t t t
bundle of His, and the only escape rhythm available below the bundle of His is a ventricular
t t t t t t t t t t t t t t t t t
escape rhythm.
t t
Test-Taking Strategy: The sinus node is supplied by right coronary artery (in 55% of people) or t t t t t t t t t t t t t t t
left coronary artery (in 45% of people), so eliminate option a. Type I AV block, also called
t t t t t t t t t t t t t t t t t
Wenckebach, is a block at the AV node, and the AV node is supplied by right coronary artery (in
t t t t t t t t t t t t t t t t t t t
90% of people) or left coronary artery (10%), so eliminate option b. The
t t t t t t t t t t t t t
LAD artery supplies the bundle of His, and blocks in this area would eliminate the possibility of
t t t t t t t t t t t t t t t t
junctional escape rhythms, so eliminate option d. Choose option c.
t t t t t t t t t t
A patient develops atrial fibrillation after abdominal surgery. Her blood pressure falls from
t t t t t t t t t t t t
110/70 mm Hg to 92/68 mm Hg. The hypotension is related to which of the following?
t t t t t t t t t t t t t t t t
a. Decrease in ventricular contractility
t t t t
b. Hypovolemia
t
c. Mural thrombi
t t
d. Decrease in ventricular filling - ➡ Correct answer: d
t t t t t t t t t
Rationale: The contribution that atrial contraction makes to ventricular filling volume is
t t t t t t t t t t t
approximately 15% to 30%. Atrial fibrillation results in quivering but not contracting atria. The
t t t t t t t t t t t t t t
loss of 15% to 30% of diastolic filling volume reduces cardiac output and can have significant
t t t t t t t t t t t t t t t t
hemodynamic consequences. Although mural thrombi also are a problem, they
t t t t t t t t t t
result in an embolic phenomenon rather than a direct decrease in cardiac output. The
t t t t t t t t t t t t t
relationship between the development of atrial fibrillation and the decrease in cardiac output
t t t t t t t t t t t t t
make hypovolemia and decrease in contractility less likely.
t t t t t t t t
answers- Cardiovascular
A patient is in cardiac and respiratory arrest. The selection of medications to reestablish cardiac
t t t t t t t t t t t t t t
function would stimulate the sympathetic nervous system beta1 receptors. This stimulation
t t t t t t t t t t t
would result in increased automaticity and which of the
t t t t t t t t t
following?
a. Increased myocardial contractility
t t t
b. Decreased left ventricular stroke work
t t t t t
c. Decreased myocardial oxygen consumption
t t t t
d. Increased left ventricular afterload - ➡ Correct answer: a
t t t t t t t t t
Rationale: The sympathetic nervous system contains alpha, beta, and dopaminergic receptors
t t t t t t t t t t
that produce various responses when stimulated. Stimulation of beta1 receptors increases
t t t t t t t t t t t
heart rate, conductivity, and myocardial contractility. Stimulation of beta2 receptors produces
t t t t t t t t t t t
vasodilation and bronchodilation. Alpha receptors, when stimulated,
t t t t t t t
produce vasoconstriction. Stimulation of dopaminergic receptors produces a vasodilating
t t t t t t t t
effect on renal, mesenteric, coronary, and cerebral vessels.
t t t t t t t
Test-Taking Strategy: Note the helpful clue in the stem: stimulate the sympathetic system and
t t t t t t t t t t t t t
recall that this results in a fight-or-flight response—the body is responding to survive. Stroke
t t t t t t t t t t t t t t
volume would increase, so eliminate option b. Afterload would increase, but this is due to alpha
t t t t t t t t t t t t t t t t
stimulation, not beta1 stimulation, so eliminate option d. Because the heart is working faster
t t t t t t t t t t t t t t
and harder, the myocardial oxygen consumption does increase, so eliminate option c.
t t t t t t t t t t t t
Remember that the primary effects of beta1 receptors are to increase heart rate, contractility,
t t t t t t t t t t t t t t
and rate of conduction. Choose option a. A memory aid that also may help is this: beta 1 beta 2, 1
t t t t t t t t t t t t t t t t t t t t t
heart 2 lungs: beta1 affects the heart, and beta2 affects the lungs.
t t t t t t t t t t t t
A patient arrived in the emergency department with complaints of chest pain. The 12-lead
t t t t t t t t t t t t t
electrocardiogram shows ST segment elevation in leads V3 and V4. Occlusion of the affected
t t t t t t t t t t t t t t
coronary artery most likely would affect perfusion to which portion of the
t t t t t t t t t t t t
conduction system? t
a. Sinoatrial (SA) node
t t t
,b. Bachmann's bundle
t t
c. Atrioventricular (AV) node
t t t
d. Bundle of His - ➡ Correct answer: d
t t t t t t t t
Rationale: ST segment elevation in leads V3 and V4 indicates injury to the anterior wall, which
t t t t t t t t t t t t t t t
would occur with occlusion of the left anterior descending (LAD) artery. In most persons, the SA
t t t t t t t t t t t t t t t t
node, Bachmann's bundle, and AV node are supplied by the right coronary artery. The bundle of
t t t t t t t t t t t t t t t t
His is supplied by the left anterior descending artery. This is why an
t t t t t t t t t t t t t
anterior myocardial infarction may cause type II second-degree AV block or third-degree AV
t t t t t t t t t t t t
heart block at the level of the bundle of His.
t t t t t t t t t t
Test-Taking Strategy: Note that options a, b, and c are part of the supraventricular conduction
t t t t t t t t t t t t t t
system. They usually are supplied by the right coronary artery. The LAD artery supplies most of
t t t t t t t t t t t t t t t t
the interventricular conduction system, including the bundle of His and
t t t t t t t t t t
the bundle branches.
t t
Oxygen delivery (DO2) is the product of which of the following?
t t t t t t t t t t
a. PaO2, hemoglobin, mean arterial pressure
t t t t t
b. SaO2, hemoglobin, cardiac output
t t t t
c. SvO2, cardiac index, SaO2
t t t t
d. PaO2, mean arterial pressure, SvO2 - ➡ Correct answer: b
t t t t t t t t t t
Rationale: Ninety-seven percent of oxygen is attached to the hemoglobin molecule, so the SaO2
t t t t t t t t t t t t t
(arterial oxygen saturation) is a more accurate reflection of the amount of oxygen in blood. The
t t t t t t t t t t t t t t t t
PaO2 represents only the 3% that is dissolved in the plasma. The lungs must put the oxygen in
t t t t t t t t t t t t t t t t t t
the blood, the hemoglobin must carry the oxygen, and the cardiac output is a reflection of how
t t t t t t t t t t t t t t t t t
well the heart is moving the blood with its hemoglobin with attached
t t t t t t t t t t t t
oxygen. SvO2 (venous oxygen saturation) is a reflection of the oxygen reserve. SvO2 is what is
t t t t t t t t t t t t t t t
left over after the tissues have extracted what they need. The mean arterial pressure is a
t t t t t t t t t t t t t t t t
reflection of organ tissue perfusion pressure but does not indicate anything about the amount
t t t t t t t t t t t t t t
of oxygen in that blood.
t t t t t
Test-Taking Strategy: Oxygen is delivered from the arterial end, so choose an option that has
t t t t t t t t t t t t t t
SaO2 instead of SvO2. Also remember that most oxygen is carried on hemoglobin. Look for SaO2
t t t t t t t t t t t t t t t t
(not PaO2) and hemoglobin. The only option with both of these is option b.
t t t t t t t t t t t t t t
, Which of the following types of block are most likely after an anterior wall myocardial infarction
t t t t t t t t t t t t t t t
(MI)?
t
a. Sinus block
t t
b. Second-degree atrioventricular (AV) block, type I
t t t t t t
c. Second-degree AV block, type II
t t t t t
d. Third-degree AV block with junctional escape rhythm - ➡ Correct answer: c
t t t t t t t t t t t t
Rationale: Anterior MI is caused by a left anterior descending (LAD) artery lesion. The LAD
t t t t t t t t t t t t t t
artery supplies the bundle of His and bundle branches, so anterior MIs may cause blocks of the
t t t t t t t t t t t t t t t t t
bundle of His or bundle branches. Second-degree AV block type II is a block at the level of the
t t t t t t t t t t t t t t t t t t t
bundle of His. If this patient does develop a third-degree AV block, it would be at the level of the
t t t t t t t t t t t t t t t t t t t t
bundle of His, and the only escape rhythm available below the bundle of His is a ventricular
t t t t t t t t t t t t t t t t t
escape rhythm.
t t
Test-Taking Strategy: The sinus node is supplied by right coronary artery (in 55% of people) or t t t t t t t t t t t t t t t
left coronary artery (in 45% of people), so eliminate option a. Type I AV block, also called
t t t t t t t t t t t t t t t t t
Wenckebach, is a block at the AV node, and the AV node is supplied by right coronary artery (in
t t t t t t t t t t t t t t t t t t t
90% of people) or left coronary artery (10%), so eliminate option b. The
t t t t t t t t t t t t t
LAD artery supplies the bundle of His, and blocks in this area would eliminate the possibility of
t t t t t t t t t t t t t t t t
junctional escape rhythms, so eliminate option d. Choose option c.
t t t t t t t t t t
A patient develops atrial fibrillation after abdominal surgery. Her blood pressure falls from
t t t t t t t t t t t t
110/70 mm Hg to 92/68 mm Hg. The hypotension is related to which of the following?
t t t t t t t t t t t t t t t t
a. Decrease in ventricular contractility
t t t t
b. Hypovolemia
t
c. Mural thrombi
t t
d. Decrease in ventricular filling - ➡ Correct answer: d
t t t t t t t t t
Rationale: The contribution that atrial contraction makes to ventricular filling volume is
t t t t t t t t t t t
approximately 15% to 30%. Atrial fibrillation results in quivering but not contracting atria. The
t t t t t t t t t t t t t t
loss of 15% to 30% of diastolic filling volume reduces cardiac output and can have significant
t t t t t t t t t t t t t t t t
hemodynamic consequences. Although mural thrombi also are a problem, they
t t t t t t t t t t
result in an embolic phenomenon rather than a direct decrease in cardiac output. The
t t t t t t t t t t t t t
relationship between the development of atrial fibrillation and the decrease in cardiac output
t t t t t t t t t t t t t
make hypovolemia and decrease in contractility less likely.
t t t t t t t t
