Deck 16: Cardiac Output Measurement

Question 1

At rest, approximately what percentage of total blood volume is stored in the venous system?

A)16%
B)32%
C)48%
D)64%

Answer 1

64%

Question 2

The normal ejection fraction is approximately:

A)less than 50%.
B)55% to 60%.
C)65% to 70%.
D)75% to 80%.

Answer 2

65% to 70%.

Question 3

Bradycardia in an adult is defined as a heart rate less than _____ beats/min.

A)50
B)60
C)100
D)120

Answer 3

60

Question 4

Which of the following best describes preload?

A)The filling volume of the left ventricle.
B)The stretch on the ventricular muscle fibers before contraction.
C)The difference between the end-systolic and end-diastolic volumes.
D)The volume of blood deposited from the right atrium into the right ventricle.

Question 5

In patients with pulmonary hypertension, the right ventricular stroke work index will be:

A)less than normal.
B)the same as normal.
C)greater than normal.
D)equal to the left ventricular stroke work index.

Question 6

Blood flow is directed to organs that have the highest metabolic needs when at rest.Which of the following organs would have the lowest metabolic needs when at rest?

A)Heart
B)Liver
C)Muscles
D)Kidneys

Question 7

Cardiac output is a product of which two variables?

A)Heart rate and stroke volume
B)Heart rate and body surface area
C)Cardiac index and blood pressure
D)Stroke volume and ejection fraction

Question 8

Which of the following does not have a direct effect on stroke volume?

A)Preload
B)Heart rate
C)Afterload
D)Contractility

Question 9

Tachycardia in an adult is defined as a heart rate greater than _____ beats/min.

A)50
B)60
C)100
D)120

Question 10

All the following are true about the ejection fraction except:

A)the normal value is about 65% to 70%.
B)it can be calculated from a nomogram.
C)the percentage is the end-diastolic volume ejected with each beat.
D)it represents the difference between end-diastolic and end-systolic volumes.

Question 11

Approximately how much blood can be lost before circulatory function and pressures are affected?

A)5%
B)15%
C)25%
D)35%

Question 12

The average cardiac output for adult men and women at rest is _____ L/min.

A)0.5
B)5
C)15
D)25

Question 13

The amount of blood pumped out of the left ventricle in 1 minute is the definition of:

A)afterload.
B)cardiac output.
C)stroke volume.
D)ejection fraction.

Question 14

What is the most important factor in assessment of the ability of the cardiovascular system to meet the body's metabolic demands?

A)Respiratory quotient (RQ)
B)Cardiac output
C)Oxygen uptake
D)Adequacy of perfusion

Question 15

The cardiac output of the right ventricle is the same as the cardiac output of the left ventricle.Compared with the left ventricle, the cardiac work index of the right ventricle is:

A)less.
B)the same.
C)somewhat greater.
D)much greater.

Question 16

To enable the heart of a well-trained athlete to produce a cardiac output of up to 35 L/min, stimulation of the heart muscle is needed through the:

A)vagus nerve.
B)phrenic nerve.
C)autonomic nervous system.
D)sympathetic nervous system.

Question 17

At rest, approximately 64% of the total blood volume is stored in the:

A)liver.
B)lungs.
C)extremities.
D)venous system.

Question 18

To standardize the measurement of cardiac output in individuals of different sizes, the value for cardiac output is divided by the person's body surface area.The result is known as:

A)cardiac work.
B)the cardiac index.
C)the standardized cardiac output.
D)the cardiac end-systolic volume.

Question 19

All of the following can affect cardiac output except:

A)race.
B)body size.
C)hematocrit.
D)tissue demand for oxygen.

Question 20

The strength of contraction of the myocardial muscle fibers is related directly to the amount of stretch on the fiber before contraction is a definition of:

A)preload.
B)Starling law.
C)cardiac contractility.
D)ventricular compliance.

Question 21

According to the Fick equation, what could cause the C(a - v)O₂ to decrease?

A)Exercise
B)High cardiac output
C)Cardiogenic shock
D)High fevers

Question 22

When ventricular function curves are performed on a patient with a suspected failing left ventricle, how does cardiac output typically change as the pulmonary capillary wedge pressure increases?

A)Cardiac output increases at first and then stays flat.
B)Cardiac output increases at first and then decreases.
C)Cardiac output decreases at first and then stays flat.
D)Cardiac output decreases at first and then increases.

Question 23

To obtain the coronary perfusion pressure, what two values are needed?

A)Afterload and preload
B)Ejection fraction and heart rate
C)Mean arterial pressure and afterload
D)Diastolic blood pressure and pulmonary capillary wedge pressure

Question 24

When the Fick method is used to calculate cardiac output, if C(a - v)O₂ is greater than expected and VO₂ is normal, cardiac output probably will be:

A)normal.
B)less than expected.
C)greater than expected.
D)unknown-insufficient information is available to answer the question.

Question 25

All the following make up the peripheral component of afterload except:

A)the radius of the vessels.
B)the length of the vessels.
C)the viscosity of the blood.
D)the elasticity or compliance of the vessels.

Question 26

All of the following may cause a decrease in ventricular compliance except:

A)inotropic drugs.
B)vasodilator drugs.
C)myocardial infarction.
D)positive end-expiratory pressure.

Question 27

All of the following can cause an increase in pulmonary vascular resistance except:

A)exercise.
B)acidosis.
C)hypoxemia.
D)release of histamine because of allergic response.

Question 28

IPPB with PEEP has what effect on preload?

A)No effect
B)A dampening effect
C)An enhancing effect
D)An unknown effect

Question 29

The filling pressure of the right heart also is known as the _____ pressure.

A)Starling
B)central venous
C)ventricular filling
D)pulmonary capillary wedge

Question 30

When ventricular function curves are performed on a patient with a suspected failing right ventricle, how does cardiac output typically change as central venous pressure increases?

A)Cardiac output increases at first and then stays flat.
B)Cardiac output increases at first and then decreases.
C)Cardiac output decreases at first and then stays flat.
D)Cardiac output decreases at first and then increases.

Question 31

What effect does spontaneous deep inspiration have on venous return?

A)No effect
B)A dampening effect
C)An enhancing effect
D)An unknown effect

Question 32

Which of the following is used to determine the afterload of the right ventricle?

A)Cardiac output
B)Pulmonary artery pressure
C)Pulmonary vascular resistance
D)Pulmonary capillary wedge pressure

Question 33

The filling pressure of the left heart also is known as the _____ pressure.

A)Starling
B)central venous
C)ventricular filling
D)pulmonary capillary wedge

Question 34

Intermittent positive-pressure breathing (IPPB) with positive end-expiratory pressure (PEEP) has what effect on afterload?

A)No effect
B)A dampening effect
C)An enhancing effect
D)An unknown effect

Question 35

A drug that increases the contractility of the heart is known as a positive:

A)inotrope.
B)dromotrope.
C)chromotrope.
D)vasoconstrictor.

Question 36

What effect does an increase in intrathoracic pressure have on venous return?

A)No effect
B)A dampening effect
C)An enhancing effect
D)An unknown effect

Question 37

What method of measuring cardiac output is most popular in intensive care units (ICUs) around the country?

A)Thermodilution
B)Fick method
C)Pulse contour method
D)Intravascular ultrasound

Question 38

Why has use of the pulmonary artery catheter diminished in many ICUs?

A)It is expensive.
B)It is difficult to place.
C)Patients complain about the discomfort.
D)Some experts believe it increases death rates.

Question 39

The resistance to ventricular ejection also is known as:

A)afterload.
B)Forrester's hemodynamic subset I.
C)Forrester's hemodynamic subset II.
D)Forrester's hemodynamic subset III.

Question 40

The greatest determinant of peripheral resistance to blood flow is:

A)the radius of the vessels.
B)the viscosity of the blood.
C)the compliance of the vessels.
D)the distance of the vessels from the heart.

Question 41

The periodic, noninvasive measurement of cardiac performance that requires only the use of a sphygmomanometer is called:

A)echocardiography.
B)electrical bioimpedance.
C)pulse contour cardiac output monitoring.
D)pulse pressure.

Question 42

Which of the following is not used in continuous cardiac output monitoring?

A)Echocardiography
B)Doppler ultrasound
C)Pulse contour cardiac output monitoring
D)Thermal dilution

Question 43

All of the following can be used to assess cardiac output noninvasively except:

A)the pulse pressure.
B)echocardiography.
C)Doppler ultrasound.
D)transthoracic electrical bioimpedance.