Deck 9: Assessment of Cardiovascular Function

Question 1

A muscle cell cannot be depolarized again during which phases of an action potential?

A) End of 0 to the beginning of 2
B) Beginning of 1 to the end of 3
C) End of 1 to the beginning of 4
D) Beginning of 0 to the middle of 3

Answer 1

D
The period from the beginning of phase 0 to the middle of phase 3 is referred to as the absolute refractory period or effective refractory period,because regardless of the strength of the stimulus,the myocyte cannot be depolarized again.

Question 2

The time required for the atrial impulse to travel through the atrioventricular node is defined as which of the following?

A) P-R segment
B) P-R interval
C) QRS interval
D) ST segment

Answer 2

B
The P-R interval ranges from 0.12 to 0.2 second and is the time it takes for the impulse initiated in the atria to travel through the atrioventricular node.The P-R segment occurs between the end of the P wave and the beginning of the QRS interval,corresponds to the 0.1-second delay that occurs within the atrioventricular node.The P-R segment is included in the P-R interval.The QRS interval represents ventricular depolarization,and the ST segment represents ventricular depolarization.

Question 3

The QRS complex represents which of the following?

A) Atrial depolarization
B) Ventricular depolarization
C) Ventricular repolarization
D) Threshold potential

Answer 3

B
Ventricular depolarization is represented on the electrocardiogram as the QRS complex.The P wave represents atrial depolarization.The T wave represents ventricular repolarization.Threshold potential is the critical level of electrical excitation reached by any cell,causing an action potential to occur.

Question 4

When a cell membrane of an excitable cell is exposed to a depolarizing current,which of the following occurs?

A) Increased influx of calcium into the cell
B) Rapid influx of sodium ions into the cell
C) Increased efflux of potassium out of the cell
D) Rapid efflux of protein molecules out of the cell

Question 5

Which of the following cardiac cells has the slowest action potential?

A) Atrial
B) Ventricular
C) Purkinje fiber
D) Sinoatrial node

Question 6

The paper speed of an electrocardiographic machine should be set at a speed of ____ mm/s.

A) 10
B) 15
C) 20
D) 25

Question 7

Each millimeter on electrocardiographic recording paper represents _____ seconds.

A) 0.02
B) 0.04
C) 0.20
D) 0.40

Question 8

Automatic electrical discharges in the myocardium normally begin within which of the following?

A) Bundle of His
B) Sinoatrial node
C) Bachmann's bundle
D) Atrioventricular node

Question 9

The fourth intercostal space at the left sternal margin is the site for which of the following electrocardiogram leads?

A) V1
B) V2
C) V3
D) V4

Question 10

The fifth intercostal space on the anterior axillary line is the site for which of the following electrocardiogram leads?

A) V3
B) V4
C) V5
D) V6

Question 11

On an electrocardiogram,the time between atrial and ventricular contraction is known as the:

A) P-R segment
B) ST segment
C) QRS interval
D) Q-T interval

Question 12

Which of the following is defined as "the ability of a cell to respond to an electrical stimulus"?

A) Conductivity
B) Rhythmicity
C) Excitability
D) Automaticity

Question 13

The ability of cardiac tissue to propagate an action potential is the definition of:

A) excitability.
B) automaticity.
C) conductivity.
D) depolarization.

Question 14

A specialized high-speed conduction system begins at which of the following points?

A) A
B) C
C) D
D) H

Question 15

Which letter in the figure identifies the anterior internodal pathway?

A) A
B) C
C) E
D) F

Question 16

Which letter in the figure identifies the cardiac cells through which there is a 100-ms delay?

A) A
B) B
C) C
D) D

Question 17

The ability of certain specialized cells of the heart to depolarize spontaneously is known as which of the following?

A) Diastasis
B) Excitability
C) Automaticity
D) Conductivity

Question 18

How many millimeters are between each heavy vertical line on electrocardiographic paper?

A) 1.0
B) 2.0
C) 4.0
D) 5.0

Question 19

The QRS vector appears downward in which of the following electrocardiogram leads?

A) II
B) V5
C) aVL
D) aVR

Question 20

Electrical stimulation of a cardiac muscle cell is the definition of which of the following?

A) Contraction
B) Refraction
C) Polarization
D) Depolarization

Question 21

Which of the following might cause sinus tachycardia?

A) Vomiting
B) Hypothermia
C) Thyrotoxicosis
D) Mediastinal tumors

Question 22

What is the cardiac rhythm depicted on the following electrocardiogram?

A) Atrial fibrillation
B) Premature atrial beats
C) Paroxysmal atrial tachycardia
D) Premature ventricular contractions

Question 23

Isovolumetric contraction of the ventricles follows which electrocardiographic event?

A) P wave
B) R wave
C) S wave
D) T wave

Question 24

What are the atrial and ventricular rates for lead I in the following electrocardiogram?

Atrial Rate Ventricular Rate

A) 75 225
B) 180 90
C) 300 75
D) 135 45

Question 25

Which of the following is the most characteristic electrocardiographic finding in myocardial infarction?

A) T wave inversion
B) ST segment elevation
C) ST segment depression
D) Downward-deflected Q waves

Question 26

The heart block that causes "dropped" beats and that is often the result of increased parasympathetic tone is called _____ block.

A) Sinoatrial
B) Mobitz type I
C) First-degree atrioventricular
D) Left bundle branch

Question 27

The aVL lead shows the electrocardiogram in the below figure.This is indicative of the occlusion of which of the following coronary arteries?

A) Left coronary artery
B) Circumflex artery
C) Right coronary artery
D) Anterior interventricular branch of the left coronary artery

Question 28

On an electrocardiogram,which of the following represents ventricular depolarization and repolarization?

A) P-R interval
B) Q-T interval
C) ST segment
D) QRS complex

Question 29

On an electrocardiogram,which of the following represents ventricular repolarization?

A) T wave
B) P-R interval
C) ST segment
D) QRS complex

Question 30

Ingestion of large quantities of coffee may cause which of the following?

A) Sinus bradycardia
B) Junctional rhythms
C) Bundle branch blocks
D) Premature ventricular beats

Question 31

What is the heart rate shown on the following ECG?

A) 60
B) 78
C) 90
D) 100

Question 32

Pressure rising in the ventricles but no blood being ejected is the definition of:

A) ventricular systole.
B) ventricular diastole.
C) isovolumetric relaxation.
D) isovolumetric contraction.

Question 33

Repolarization of the papillary muscles or remnants of ventricular repolarization appears on an electrocardiogram as a:

A) P wave.
B) T wave.
C) U wave.
D) J point.

Question 34

The right ventricle peak systolic pressure is represented by _____ millimeters of mercury.

A) 15
B) 25
C) 80
D) 120

Question 35

What is the name of the following cardiac arrhythmia?

A) Paroxysmal atrial tachycardia
B) Atrial premature depolarization
C) Premature ventricular contractions
D) Wolff-Parkinson-White syndrome

Question 36

A prolonged R-R interval indicates which of the following kinds of cardiac arrhythmia?

A) Atrial fibrillation
B) Sinoatrial block
C) Premature ventricular beats
D) Paroxysmal atrial tachycardia

Question 37

b-Adrenergic blocking agents,such as propranolol,can cause:

A) sinoatrial block.
B) sinus tachycardia.
C) sinus bradycardia.
D) premature atrial beats.

Question 38

What is the heart rate depicted on the following electrocardiogram?

A) 60
B) 80
C) 100
D) 120

Question 39

What is the heart rate shown on the following electrocardiogram?

A) 150
B) 200
C) 250
D) 300

Question 40

During diastasis,which of the following occurs within the ventricles?

A) Pressure increases.
B) Blood enters slowly.
C) Pressure falls dramatically.
D) Blood pushes against the semilunar valves.

Question 41

Which of the following lumens will not appear on a cross-sectional view of a triple-lumen pulmonary artery catheter at 20 cm back from the tip?

A) Distal
B) Inflation
C) Proximal
D) Thermistor

Question 42

Falsely elevated systolic and diastolic blood pressure readings can occur when using either a manual or an automatic system because of which of the following?

A) Improper positioning
B) Motion artifacts
C) Undersized cuff
D) Improper inflation

Question 43

At what point in the figure do the semilunar valves close?

A) A
B) B
C) C
D) D

Question 44

The cuff of a sphygmomanometer should be inflated to _____ mm Hg above the point when the radial pulse disappears.

A) 10
B) 20
C) 30
D) 40

Question 45

At what point in the figure do the atrioventricular valves close?

A) B
B) D
C) E
D) F

Question 46

The right heart catheterization waveform in the figure that represents pressure in the right ventricle is which of the following?

A) A
B) B
C) C
D) D

Question 47

On an atrial pressure tracing,which wave corresponds to atrial diastole?

A) a wave
B) c wave
C) R wave
D) P wave

Question 48

The thermistor is located ____ cm back from the tip of a pulmonary artery catheter.

A) 2
B) 10
C) 30
D) 50

Question 49

Which port on a Swan-Ganz catheter is used to measure cardiac output?

A) Distal
B) Inflation
C) Proximal
D) Thermistor

Question 50

The first sound heard,by stethoscope,when deflating a sphygmomanometer cuff is known as which of the following?

A) Atrial systole
B) Systolic pressure
C) First heart sound
D) Diastolic pressure

Question 51

The proximal opening on a pulmonary artery catheter is used to measure:

A) cardiac output.
B) central venous pressure.
C) pulmonary artery pressure.
D) pulmonary capillary wedge pressure.

Question 52

A phonocardiogram is used to detect which of the following heart sounds?

A) S1 and S2
B) S2 and S3
C) S3 and S4
D) S1 and S4

Question 53

A pulmonary artery catheter introduced via the antecubital route is currently at the 50-cm mark and is showing the tracing below.Is there a problem with this catheter?

A) Yes; the balloon has ruptured.
B) No; it's in the pulmonary artery.
C) Yes; it's knotted in the right ventricle.
D) No; it's wedged in a pulmonary capillary.

Question 54

Closure of the semilunar valves and opening of the atrioventricular valves is associated with which heart sound?

A) S1
B) S2
C) S3
D) S4

Question 55

The atrial kick becomes important to ventricular filling during which of the following?

A) Atrial flutter
B) Atrial fibrillation
C) Ventricular asystole
D) Ventricular tachycardia

Question 56

Other than air,the gas that is commonly used to inflate the balloon on a pulmonary artery catheter is:

A) helium.
B) nitrogen.
C) oxygen.
D) carbon dioxide.

Question 57

Pulmonary artery occlusion pressure can be used to estimate:

A) left-atrial preload.
B) left-atrial afterload.
C) left-ventricular end-diastolic pressure.
D) right-ventricular end-diastolic pressure.

Question 58

The a wave on an arterial pressure tracing is a result of which of the following during a cardiac cycle?

A) Atrial systole
B) Atrial diastole
C) Ventricular systole
D) Ventricular diastole

Question 59

Which of the following is true concerning junctional rhythms?

A) They produce no P waves.
B) They can produce inverted P waves.
C) They are only generated high in the atrioventricular node.
D) Their rates can vary from 60 beats/min to 80 beats/min.

Question 60

When does the atrial kick begin?

A) Just before atrial systole
B) During atrial repolarization
C) During the impulse delay in the atrioventricular node
D) Simultaneously with ventricular excitation

Question 61

Systemic vascular resistance is 1700 dynes cm⁻⁵.Which of the following is consistent with this value?

A) Elevated left-ventricular afterload
B) Elevated right-ventricular afterload
C) Decreased left-ventricular preload
D) Decreased right-ventricular preload

Question 62

Which of the following is defined as the resistance that a ventricle must overcome to eject blood?

A) Stroke work
B) Stroke index
C) Ventricular preload
D) Ventricular afterload

Question 63

How long are adult pulmonary artery catheters?

A) 60 cm
B) 80 cm
C) 100 cm
D) 110 cm

Question 64

Which of the following lumens found in a standard balloon floatation catheter would be used to obtain a mixed venous blood sample?

A) Balloon lumen
B) Distal lumen
C) Proximal lumen
D) Thermodilution lumen

Question 65

Which of the following is a type of pressure transducer that uses a metal bellows and a Wheatstone bridge?

A) Resistive (or resistance)
B) Strain gauge
C) Variable inductance
D) Variable capacitance

Question 66

Which of the following represents the port on a pulmonary artery catheter used to take measurements that estimate right-ventricular end-diastolic pressure?

A) Distal
B) Balloon
C) Proximal
D) Thermistor

Question 67

The display from the proximal port of a pulmonary artery catheter reads 12 cm H₂O.This measurement is which of the following?

A) Stroke work index
B) Central venous pressure
C) Pulmonary artery pressure
D) Pulmonary capillary wedge pressure

Question 68

What is the cardiac index (CI)when cardiac output = 5.0 mL/min and body surface area (BSA)= 2.9 m²?

A) 1.72 L/min/m2
B) 1.67 L/min/m2
C) 2.10 L/min/m2
D) 12.5 L/min/m2

Question 69

Rupture of the pulmonary artery catheter balloon can cause which of the following?

A) Atrial flutter
B) Air embolism
C) Pneumothorax
D) Pulmonary infarction

Question 70

What is the cardiac output,by using the direct Fick method,for a patient with the following hemodynamic values?
$\mathrm{PaO}_{2}=80 \mathrm{~mm} \mathrm{Hg} \quad \mathrm{SaO}_{2}=90 \% \quad \mathrm{Hb}=14 \mathrm{gm} \%$

$\begin{array}{c}\mathrm{P}\overline{v} \mathrm{O}_{2}=35 \mathrm{~mm} \mathrm{Hg} \quad \mathrm{S}\overline{v}_{2}=65 \% \quad \mathrm{P}_{\mathrm{B}}=760 \mathrm{~mm} \mathrm{Hg} \\\qquad \mathrm{VO}_{2}=210 \mathrm{~mL} / \mathrm{min}\end{array}$

A) 3.5 mL/min
B) 4.36 mL/min
C) 5.83 mL/min
D) 6.15 mL/min

Question 71

What is the cardiac output when oxygen (O₂)consumption = 200 mL/min,arterial O₂ content = 21 vol%,and mixed venous O₂ content = 15 vol%?

A) 3.3 mL/min
B) 4.3 mL/min
C) 5.3 mL/min
D) 6.3 mL/min

Question 72

Which of the following events can lead to ventricular fibrillation?

A) A ventricular rate of ninety beats a minute
B) A premature ventricular beat that occurs during the T wave
C) The presence of saw tooth waves instead of P waves on an electrocardiogram
D) An increased width of the QRS complex

Question 73

Which of the following formulas represents cardiac output (CO)?

A) CO = cardiac index * body surface area
B) CO = stroke volume * body surface area
C) CO = heart rate * stroke volume
D) CO = oxygen consumption * (CAO₂ - CaO₂)

Question 74

Which of the following can increase pulmonary vascular resistance?

A) Alveolar hypoxia
B) Moderate hypoxemia
C) Decreased parasympathetic tone
D) Recruitment of pulmonary vessels

Question 75

Right-ventricular afterload can be estimated by using which equation?

A) (MAP) * (SV) * (0.00136)
B) (MPAP) * (SV) * (0.00136)
C) (MAP - MRAP/CO) * 80
D) (MPAP - MLAP/CO) * 80

Question 76

What is the cardiac output when O₂ consumption = 180 mL/min,arterial O₂ content = 18.4 vol%,and mixed venous O₂ content = 14.4 vol%.

A) 4.5 mL/min
B) 5.5 mL/min
C) 6.5 mL/min
D) 7.5 mL/min

Question 77

Which of the following will cause an increase in systemic vascular resistance?

A) Hydralazine
B) Nitroglycerin
C) Polycythemia
D) Moderate hypoxemia