CCRN PRACTICE QUESTIONS – CARDIOVASCULAR
EXAM
A patient is in cardiac and respiratory arrest. The selection of medications to reestablish cardiac
function would stimulate the sympathetic nervous system beta1 receptors. This stimulation would
result in increased automaticity and which of the
following?
a. Increased myocardial contractility
b. Decreased left ventricular stroke work
c. Decreased myocardial oxygen consumption
d. Increased left ventricular afterload Answers: Correct answer: a
Rationale: The sympathetic nervous system contains alpha, beta, and dopaminergic receptors that
produce various responses when stimulated. Stimulation of beta1 receptors increases heart rate,
conductivity, and myocardial contractility. Stimulation of beta2 receptors produces vasodilation and
bronchodilation. Alpha receptors, when stimulated,
produce vasoconstriction. Stimulation of dopaminergic receptors produces a vasodilating
effect on renal, mesenteric, coronary, and cerebral vessels.
Test-Taking Strategy: Note the helpful clue in the stem: stimulate the sympathetic system and recall
that this results in a fight-or-flight response—the body is responding to survive. Stroke volume would
increase, so eliminate option b. Afterload would increase, but this is due to alpha stimulation, not
beta1 stimulation, so eliminate option d. Because the heart is working faster and harder, the
myocardial oxygen consumption does increase, so eliminate option c. Remember that the primary
effects of beta1 receptors are to increase heart rate, contractility, and rate of conduction. Choose
option a. A memory aid that also may help is this: beta 1 beta 2, 1 heart 2 lungs: beta1 affects the
heart, and beta2 affects the lungs.
A patient arrived in the emergency department with complaints of chest pain. The 12-lead
electrocardiogram shows ST segment elevation in leads V3 and V4. Occlusion of the affected
coronary artery most likely would affect perfusion to which portion of the
conduction system?
a. Sinoatrial (SA) node
b. Bachmann's bundle
c. Atrioventricular (AV) node
d. Bundle of His Answers: Correct answer: d
Rationale: ST segment elevation in leads V3 and V4 indicates injury to the anterior wall, which would
occur with occlusion of the left anterior descending (LAD) artery. In most persons, the SA node,
Bachmann's bundle, and AV node are supplied by the right coronary artery. The bundle of His is
supplied by the left anterior descending artery. This is why an
anterior myocardial infarction may cause type II second-degree AV block or third-degree AV heart
block at the level of the bundle of His.
Test-Taking Strategy: Note that options a, b, and c are part of the supraventricular conduction
system. They usually are supplied by the right coronary artery. The LAD artery supplies most of the
interventricular conduction system, including the bundle of His and
the bundle branches.
Oxygen delivery (DO2) is the product of which of the following?
a. PaO2, hemoglobin, mean arterial pressure
b. SaO2, hemoglobin, cardiac output
,c. SvO2, cardiac index, SaO2
d. PaO2, mean arterial pressure, SvO2 Answers: Correct answer: b
Rationale: Ninety-seven percent of oxygen is attached to the hemoglobin molecule, so the SaO2
(arterial oxygen saturation) is a more accurate reflection of the amount of oxygen in blood. The PaO2
represents only the 3% that is dissolved in the plasma. The lungs must put the oxygen in the blood,
the hemoglobin must carry the oxygen, and the cardiac output is a reflection of how well the heart is
moving the blood with its hemoglobin with attached
oxygen. SvO2 (venous oxygen saturation) is a reflection of the oxygen reserve. SvO2 is what is left
over after the tissues have extracted what they need. The mean arterial pressure is a reflection of
organ tissue perfusion pressure but does not indicate anything about the amount of oxygen in that
blood.
Test-Taking Strategy: Oxygen is delivered from the arterial end, so choose an option that has SaO2
instead of SvO2. Also remember that most oxygen is carried on hemoglobin. Look for SaO2 (not
PaO2) and hemoglobin. The only option with both of these is option b.
Which of the following types of block are most likely after an anterior wall myocardial infarction (MI)?
a. Sinus block
b. Second-degree atrioventricular (AV) block, type I
c. Second-degree AV block, type II
d. Third-degree AV block with junctional escape rhythm Answers: Correct answer: c
Rationale: Anterior MI is caused by a left anterior descending (LAD) artery lesion. The LAD artery
supplies the bundle of His and bundle branches, so anterior MIs may cause blocks of the bundle of
His or bundle branches. Second-degree AV block type II is a block at the level of the bundle of His. If
this patient does develop a third-degree AV block, it would be at the level of the bundle of His, and
the only escape rhythm available below the bundle of His is a ventricular escape rhythm.
Test-Taking Strategy: The sinus node is supplied by right coronary artery (in 55% of people) or left
coronary artery (in 45% of people), so eliminate option a. Type I AV block, also called Wenckebach,
is a block at the AV node, and the AV node is supplied by right coronary artery (in 90% of people) or
left coronary artery (10%), so eliminate option b. The
LAD artery supplies the bundle of His, and blocks in this area would eliminate the possibility of
junctional escape rhythms, so eliminate option d. Choose option c.
A patient develops atrial fibrillation after abdominal surgery. Her blood pressure falls from 110/70 mm
Hg to 92/68 mm Hg. The hypotension is related to which of the following?
a. Decrease in ventricular contractility
b. Hypovolemia
c. Mural thrombi
d. Decrease in ventricular filling Answers: Correct answer: d
Rationale: The contribution that atrial contraction makes to ventricular filling volume is approximately
15% to 30%. Atrial fibrillation results in quivering but not contracting atria. The loss of 15% to 30% of
diastolic filling volume reduces cardiac output and can have significant hemodynamic consequences.
Although mural thrombi also are a problem, they
result in an embolic phenomenon rather than a direct decrease in cardiac output. The relationship
between the development of atrial fibrillation and the decrease in cardiac output make hypovolemia
and decrease in contractility less likely.
Test-Taking Strategy: Relate recent changes in patient status to recent occurrences. The patient had
a change in atrial function, so select an option that results in loss of atrial contraction or "kick."
Choose option d.
, A shift in the point of maximal impulse (PMI) to the fifth left intercostal space at the anterior axillary
line could be caused by any of these conditions except:
a. left ventricular hypertrophy.
b. right tension pneumothorax.
c. pericardial effusion.
d. right pleural effusion. Answers: Correct answer: c
Rationale: In pericardial effusion or tamponade, there is frequently loss of palpability of the apical
impulse because of the fluid layer. Left ventricular hypertrophy, right tension pneumothorax, and a
right pleural effusion could shift the PMI left of normal. Normally the PMI is located at the fifth left
intercostal space at the midclavicular line.
Test-Taking Strategy: Look for the process that would not shift the PMI to the left of the normal
position. Picture the process. If the left ventricle is big, it will extend farther to the left. If there is
excessive pressure or volume on the right side, it will push the heart toward the left. Pericardial
effusion will decrease the intensity of the PMI but it won't shift it.
Choose option c.
An S4 is an expected physical finding in which of the following?
a. Acute myocardial infarction
b. Left ventricular failure
c. Pericarditis
d. Bundle branch block Answers: Correct answer: a
Rationale: An S4 is an indication of ventricular noncompliance. Noncompliance is caused by
ischemia, infarction, hypertrophy, cardiac tamponade, constrictive pericarditis, or restrictive
cardiomyopathy. Left ventricular failure would cause an S3. Pericarditis would cause a pericardial
friction rub. Bundle branch blocks cause splits (left bundle branch block causes a paradoxical split of
S2, and right bundle branch block causes a split of S1 and
increased splitting of S2 during inspiration).
Test-Taking Strategy: Read the question carefully and note the key word expected. Associate S4 with
a noncompliant ventricle. Ischemia, infarction, and hypertrophy cause noncompliance. Choose option
a.
A woman, age 35 years, reports the feeling that her heart is racing out of her chest, shortness of
breath, and dizziness on admission to the critical care unit. The patient reports a history of a "floppy
valve" for the past 10 years. Which of the following is true regarding the murmur of mitral valve
prolapse?
a. Early systolic with a low-pitched, blowing quality
b. Radiates to the carotid arteries
c. Loudest at the lower left sternal border
d. Usually accompanied by a midsystolic click Answers: Correct answer: d
Rationale: The murmur of mitral valve prolapse is caused by mitral regurgitation. Mitral regurgitation
murmurs are high-pitched, blowing, systolic murmurs that are loudest at the apex and radiate to the
axilla. When specific to mitral valve prolapse, a midsystolic click usually is heard at the apex, and the
murmur follows the click such as S1, click, murmur, S2.
Test-Taking Strategy: Remember that all murmurs are high-pitched with the exceptions of mitral
stenosis and tricuspid stenosis, so eliminate option a. Radiation is in the direction of blood flow. In
this case, the direction is from the left ventricle to the left atrium, which causes the radiation to the
axilla, not the carotid arteries. Eliminate option b. Mitral regurgitation murmurs are loudest at the
apex, also called the mitral area. Eliminate option c. The click is associated with a mitral valve leaflet
bulging toward the left atrium during midsystole. Remember that mitral valve prolapse also is called
click-murmur syndrome. Choose option d.
EXAM
A patient is in cardiac and respiratory arrest. The selection of medications to reestablish cardiac
function would stimulate the sympathetic nervous system beta1 receptors. This stimulation would
result in increased automaticity and which of the
following?
a. Increased myocardial contractility
b. Decreased left ventricular stroke work
c. Decreased myocardial oxygen consumption
d. Increased left ventricular afterload Answers: Correct answer: a
Rationale: The sympathetic nervous system contains alpha, beta, and dopaminergic receptors that
produce various responses when stimulated. Stimulation of beta1 receptors increases heart rate,
conductivity, and myocardial contractility. Stimulation of beta2 receptors produces vasodilation and
bronchodilation. Alpha receptors, when stimulated,
produce vasoconstriction. Stimulation of dopaminergic receptors produces a vasodilating
effect on renal, mesenteric, coronary, and cerebral vessels.
Test-Taking Strategy: Note the helpful clue in the stem: stimulate the sympathetic system and recall
that this results in a fight-or-flight response—the body is responding to survive. Stroke volume would
increase, so eliminate option b. Afterload would increase, but this is due to alpha stimulation, not
beta1 stimulation, so eliminate option d. Because the heart is working faster and harder, the
myocardial oxygen consumption does increase, so eliminate option c. Remember that the primary
effects of beta1 receptors are to increase heart rate, contractility, and rate of conduction. Choose
option a. A memory aid that also may help is this: beta 1 beta 2, 1 heart 2 lungs: beta1 affects the
heart, and beta2 affects the lungs.
A patient arrived in the emergency department with complaints of chest pain. The 12-lead
electrocardiogram shows ST segment elevation in leads V3 and V4. Occlusion of the affected
coronary artery most likely would affect perfusion to which portion of the
conduction system?
a. Sinoatrial (SA) node
b. Bachmann's bundle
c. Atrioventricular (AV) node
d. Bundle of His Answers: Correct answer: d
Rationale: ST segment elevation in leads V3 and V4 indicates injury to the anterior wall, which would
occur with occlusion of the left anterior descending (LAD) artery. In most persons, the SA node,
Bachmann's bundle, and AV node are supplied by the right coronary artery. The bundle of His is
supplied by the left anterior descending artery. This is why an
anterior myocardial infarction may cause type II second-degree AV block or third-degree AV heart
block at the level of the bundle of His.
Test-Taking Strategy: Note that options a, b, and c are part of the supraventricular conduction
system. They usually are supplied by the right coronary artery. The LAD artery supplies most of the
interventricular conduction system, including the bundle of His and
the bundle branches.
Oxygen delivery (DO2) is the product of which of the following?
a. PaO2, hemoglobin, mean arterial pressure
b. SaO2, hemoglobin, cardiac output
,c. SvO2, cardiac index, SaO2
d. PaO2, mean arterial pressure, SvO2 Answers: Correct answer: b
Rationale: Ninety-seven percent of oxygen is attached to the hemoglobin molecule, so the SaO2
(arterial oxygen saturation) is a more accurate reflection of the amount of oxygen in blood. The PaO2
represents only the 3% that is dissolved in the plasma. The lungs must put the oxygen in the blood,
the hemoglobin must carry the oxygen, and the cardiac output is a reflection of how well the heart is
moving the blood with its hemoglobin with attached
oxygen. SvO2 (venous oxygen saturation) is a reflection of the oxygen reserve. SvO2 is what is left
over after the tissues have extracted what they need. The mean arterial pressure is a reflection of
organ tissue perfusion pressure but does not indicate anything about the amount of oxygen in that
blood.
Test-Taking Strategy: Oxygen is delivered from the arterial end, so choose an option that has SaO2
instead of SvO2. Also remember that most oxygen is carried on hemoglobin. Look for SaO2 (not
PaO2) and hemoglobin. The only option with both of these is option b.
Which of the following types of block are most likely after an anterior wall myocardial infarction (MI)?
a. Sinus block
b. Second-degree atrioventricular (AV) block, type I
c. Second-degree AV block, type II
d. Third-degree AV block with junctional escape rhythm Answers: Correct answer: c
Rationale: Anterior MI is caused by a left anterior descending (LAD) artery lesion. The LAD artery
supplies the bundle of His and bundle branches, so anterior MIs may cause blocks of the bundle of
His or bundle branches. Second-degree AV block type II is a block at the level of the bundle of His. If
this patient does develop a third-degree AV block, it would be at the level of the bundle of His, and
the only escape rhythm available below the bundle of His is a ventricular escape rhythm.
Test-Taking Strategy: The sinus node is supplied by right coronary artery (in 55% of people) or left
coronary artery (in 45% of people), so eliminate option a. Type I AV block, also called Wenckebach,
is a block at the AV node, and the AV node is supplied by right coronary artery (in 90% of people) or
left coronary artery (10%), so eliminate option b. The
LAD artery supplies the bundle of His, and blocks in this area would eliminate the possibility of
junctional escape rhythms, so eliminate option d. Choose option c.
A patient develops atrial fibrillation after abdominal surgery. Her blood pressure falls from 110/70 mm
Hg to 92/68 mm Hg. The hypotension is related to which of the following?
a. Decrease in ventricular contractility
b. Hypovolemia
c. Mural thrombi
d. Decrease in ventricular filling Answers: Correct answer: d
Rationale: The contribution that atrial contraction makes to ventricular filling volume is approximately
15% to 30%. Atrial fibrillation results in quivering but not contracting atria. The loss of 15% to 30% of
diastolic filling volume reduces cardiac output and can have significant hemodynamic consequences.
Although mural thrombi also are a problem, they
result in an embolic phenomenon rather than a direct decrease in cardiac output. The relationship
between the development of atrial fibrillation and the decrease in cardiac output make hypovolemia
and decrease in contractility less likely.
Test-Taking Strategy: Relate recent changes in patient status to recent occurrences. The patient had
a change in atrial function, so select an option that results in loss of atrial contraction or "kick."
Choose option d.
, A shift in the point of maximal impulse (PMI) to the fifth left intercostal space at the anterior axillary
line could be caused by any of these conditions except:
a. left ventricular hypertrophy.
b. right tension pneumothorax.
c. pericardial effusion.
d. right pleural effusion. Answers: Correct answer: c
Rationale: In pericardial effusion or tamponade, there is frequently loss of palpability of the apical
impulse because of the fluid layer. Left ventricular hypertrophy, right tension pneumothorax, and a
right pleural effusion could shift the PMI left of normal. Normally the PMI is located at the fifth left
intercostal space at the midclavicular line.
Test-Taking Strategy: Look for the process that would not shift the PMI to the left of the normal
position. Picture the process. If the left ventricle is big, it will extend farther to the left. If there is
excessive pressure or volume on the right side, it will push the heart toward the left. Pericardial
effusion will decrease the intensity of the PMI but it won't shift it.
Choose option c.
An S4 is an expected physical finding in which of the following?
a. Acute myocardial infarction
b. Left ventricular failure
c. Pericarditis
d. Bundle branch block Answers: Correct answer: a
Rationale: An S4 is an indication of ventricular noncompliance. Noncompliance is caused by
ischemia, infarction, hypertrophy, cardiac tamponade, constrictive pericarditis, or restrictive
cardiomyopathy. Left ventricular failure would cause an S3. Pericarditis would cause a pericardial
friction rub. Bundle branch blocks cause splits (left bundle branch block causes a paradoxical split of
S2, and right bundle branch block causes a split of S1 and
increased splitting of S2 during inspiration).
Test-Taking Strategy: Read the question carefully and note the key word expected. Associate S4 with
a noncompliant ventricle. Ischemia, infarction, and hypertrophy cause noncompliance. Choose option
a.
A woman, age 35 years, reports the feeling that her heart is racing out of her chest, shortness of
breath, and dizziness on admission to the critical care unit. The patient reports a history of a "floppy
valve" for the past 10 years. Which of the following is true regarding the murmur of mitral valve
prolapse?
a. Early systolic with a low-pitched, blowing quality
b. Radiates to the carotid arteries
c. Loudest at the lower left sternal border
d. Usually accompanied by a midsystolic click Answers: Correct answer: d
Rationale: The murmur of mitral valve prolapse is caused by mitral regurgitation. Mitral regurgitation
murmurs are high-pitched, blowing, systolic murmurs that are loudest at the apex and radiate to the
axilla. When specific to mitral valve prolapse, a midsystolic click usually is heard at the apex, and the
murmur follows the click such as S1, click, murmur, S2.
Test-Taking Strategy: Remember that all murmurs are high-pitched with the exceptions of mitral
stenosis and tricuspid stenosis, so eliminate option a. Radiation is in the direction of blood flow. In
this case, the direction is from the left ventricle to the left atrium, which causes the radiation to the
axilla, not the carotid arteries. Eliminate option b. Mitral regurgitation murmurs are loudest at the
apex, also called the mitral area. Eliminate option c. The click is associated with a mitral valve leaflet
bulging toward the left atrium during midsystole. Remember that mitral valve prolapse also is called
click-murmur syndrome. Choose option d.
