Chapter 13 Determinants and Assessment of Cardiac Function Flashcards
1) A patient’s cardiac index will be calculated. What nursing interventions are necessary before this calculation is completed?
Note: Credit will be given only if all correct choices and no incorrect choices are selected.
Select all that apply.
1. Assure that there is an accurate current weight on the medical record.
2. Compare fluid input and output for the last 12 hours.
3. Measure the patient’s height.
4. Figure the patient’s age in years and months.
5. Obtain the patient’s current heart rate.
Answer: 1, 3, 5
Explanation: 1. Weight is a component of cardiac index.
2. There is no need to compare fluid intake and output in order to calculate cardiac index.
3. Height is used to calculate cardiac index.
4. Age is not a consideration when calculating cardiac index.
5. Heart rate is a component of cardiac index.
2) A patient is scheduled for an echocardiogram with measurement of ejection fraction. The nurse explains to the patient that this test will provide the most information about which cardiac characteristic?
1. The amount of blood the heart pumps every minute
2. The strength of the heartbeat
3. The amount of resistance the heart beats against
4. The amount of blood in the heart before it beats
Answer: 2
Explanation: 1. The amount of blood the heart pumps every minute is the cardiac output. Ejection fraction is related to cardiac output, but describing cardiac output does not fully explain ejection fraction.
2. Contractility is defined as the force of myocardial contraction and reflects the ability of the heart muscle to work independently of preload and afterload: the ability to function as a pump. Ejection fraction is a measure of the percent of blood ejected with each stroke volume and is used as an index of myocardial function.
3. Afterload is the amount of resistance the heart must beat against. Increasing afterload will affect both ejection fraction and cardiac output.
4. Preload represents the volume of blood in the ventricle at the end of diastole. A low preload can result in low cardiac output and may also affect ejection fraction.
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3) Testing indicates that a patient has a high preload. What changes would the nurse expect in this patient’s cardiac function?
Note: Credit will be given only if all correct choices and no incorrect choices are selected.
Select all that apply.
1. Heart rate will decrease.
2. Afterload will increase.
3. Stroke volume will decrease.
4. Stoke volume will increase.
5. Blood pressure will decrease.
Answer: 3, 4
Explanation: 1. It is not possible to predict what change in heart rate will occur in the face of increased preload. Depending on the pathophysiology causing the increased preload, the rate may increase, may decrease, or may stay the same.
2. Afterload represents the force the heart must overcome to pump blood. It is not affected by preload.
3. If the increase in preload is high enough that a critical point is reached, stroke volume will decrease.
4. The greater the volume of blood in the ventricle, the greater the amount of stretch that the fibers experience. To a point, this increase in stretch will result in an increase in stroke volume.
5. It is not possible to determine if an increase in preload will cause a decrease in blood pressure. In most cases, increased preload will result in increased stroke volume, which will result in increased blood pressure.
4) A patient with a steadily increasing preload was experiencing a corresponding increase in stroke volume, but it has now begun to decrease. Which rationale would the nurse provide for this occurrence?
1. This fluctuation will occur until maximum preload has been reached.
2. The patient’s heart rate is increasing, which causes a drop in stroke volume.
3. The patient’s preload has reached a critical point and now stroke volume will decrease.
4. It is necessary to assess for a secondary pathophysiological event causing the stroke volume to decrease.
Answer: 3
Explanation: 1. There is a point of maximum preload, but the cardiac output does not fluctuate until it is reached.
2. The information in this question does not support increase in the heart rate.
3. Until a critical point is reached, as preload increases, so does stroke volume. An optimal preload leads to an optimal stroke volume. Once past this point, an increase in preload results in a decrease in stroke volume. If the heart receives too much preload, it cannot effectively pump out that volume and stroke volume decreases. Stroke volume decreases because too much volume causes excessive stretching of the myocardial fibers and the ventricles cannot effectively contract.
4. There is no need to look for a different pathophysiological event, as the event at present is sufficient to cause decrease in cardiac output.
5) A patient is diagnosed with septic shock and has a decrease in afterload. The nurse would expect which initial changes in the patient’s cardiac status?
Note: Credit will be given only if all correct choices and no incorrect choices are selected.
Select all that apply.
1. Increase in cardiac output
2. Increase in blood pressure
3. Decrease in cardiac output
4. Decrease in blood pressure
5. No change in blood pressure or cardiac output
Answer: 1, 4
Explanation: 1. Decreased afterload causes cardiac output to increase. This will occur initially in septic shock, but will change as sepsis continues.
2. Since blood pressure is a product of cardiac output and afterload, a decrease in afterload causes a decrease in blood pressure.
3. Initially the decrease in afterload will increase cardiac output.
4. Decrease in afterload results in decrease in blood pressure.
5. Changes in afterload will change both blood pressure and cardiac output.
6) It is determined that a patient has poor cardiac contractility. The nurse would anticipate administering which type of drugs to improve contractility?
Note: Credit will be given only if all correct choices and no incorrect choices are selected.
Select all that apply.
1. Cardiac glycosides
2. Loop diuretics
3. Sympathomimetic agents
4. Phosphodiesterase inhibitors
5. Angiotension-converting enzyme (ACE) inhibitors
Answer: 1, 3, 4
Explanation: 1. Cardiac glycosides such as digoxin are positive inotropes and improve cardiac contractility.
2. Diuretics are given to decrease the workload on the heart by decreasing fluid overload. They are not given to specifically improve cardiac contractility.
3. Dopamine and dobutamine are sympathomimetic agents given to improve cardiac contractility.
4. Phosphodiesterase inhibitors such as inamrinone and milrinone improve cardiac contractility.
5. ACE inhibitors affect afterload and preload, but do not directly affect myocardial contractility
7) A patient is admitted with the complaint of chest pain. Questions about which history will best help the nurse determine if the pain is from cardiac or pulmonary origin?
1. Deficits in movement, timing of the pain, and dietary changes in the last 24 hours
2. What precipitated the pain, what it feels like, and where it is located
3. Changes in dietary habits, smoking history, and presence of cough
4. What home remedies were tried, activity level, and fluid intake changes
Answer: 2
Explanation: 1. Deficits in movement, timing of the pain, and dietary changes in the last 24 hours are not associated with either cardiac or pulmonary pain.
2. Precipitating factors, quality, and location will help the healthcare team discriminate between pain of cardiac origin and pain of respiratory origin.
3. This is important information to obtain, but would not help differentiate between pain of cardiac origin and pain of respiratory origin.
4. This is important information, but would not help to differentiate between pain of cardiac origin and pain of respiratory origin.
8) Which assessment techniques will the nurse use to evaluate the patient’s cardiac output?
Note: Credit will be given only if all correct choices and no incorrect choices are selected.
Select all that apply.
1. Inspection of color changes in the periphery
2. Strength of pulses
3. Percussion of heart borders
4. Auscultation of heart sounds
5. Pulse pressure determination
Answer: 1, 2, 4, 5
Explanation: 1. Color changes in the periphery can indicate decreased cardiac output.
2. Strength of pulse is an indirect measure of cardiac output and contractility.
3. Percussion is incorrect because it measures heart size very crudely but not output.
4. Auscultation helps the nurse assess heart rate and rhythm, which can alter cardiac output.
5. Determination of pulse pressure is an indirect measure of stroke volume, which is a component of cardiac output.
9) A patient has been admitted with chest pain and generalized discomfort. Which assessment is essential for the nurse to set realistic goals for patient therapy and education?
1. The patient’s functional status prior to illness
2. Family history of disease, diet history, and prior medical history
3. Demographic data including age, sex, race, and weight of patient
4. Cardiovascular risk factors, such as history of smoking and stress level
Answer: 1
Explanation: 1. Knowledge of the patient’s functional status prior to illness assists the nurse in setting goals that are realistic for the patient. The nurse must know the patient’s pre-illness capabilities.
2. Family history, diet history, and prior medical history are important assessment components but do not directly indicate the patient’s capabilities.
3. Demographic data is not as important as other assessment components for use in determining realistic goals.
4. Cardiovascular risk factors, smoking history, and stress level may indicate areas in which education is needed but do not specifically address goals of therapy.
10) The nurse has auscultated the patient’s heart sounds and has measured vital signs. Which finding would the nurse evaluate as indicating greatest need for additional assessment?
1. Pulse pressure of 38 mm Hg
2. Bounding, vigorous pulse
3. Split of S2
4. Apical pulse of 66
Answer: 3
Explanation: 1. The pulse pressure reflects how much the heart can raise the pressure in the arterial system with each beat. Pulse pressure of 30 to 40 mm Hg does not indicate cause for concern because it is within the normal pulse pressure range.
2. A bounding vigorous pulse indicates increased myocardial contractility and would require additional assessment. This is not the priority need for reassessment.
3. The split of S2 indicates that one ventricle is emptying earlier or later than another and that contractility may, therefore, be diminished. This may be a result of a structural defect, a mechanical defect, or an electrical defect. This is the priority need for additional assessment.
4. The normal range of apical pulse is 60 to 80, so this is not a priority for additional assessment.
11) A patient is admitted with a decrease in cardiac output. Which assessment findings would the nurse attribute to that condition?
1. Increased output of very clear urine
2. Cool hands and feet
3. Localized edema in the calf
4. Bounding apical impulse
Answer: 2
Explanation: 1. A decrease in cardiac output generally results in a decrease in urine output.
2. Cool distal extremities may be a useful marker of decreased cardiac output.
3. Localized edema in the calf is indicative of obstruction of venous blood flow from a clot in a leg vein.
4. The apical impulse would more likely be decreased when cardiac output is decreased.
12) It is suspected that a patient who was severely injured in an automobile accident may have had a myocardial infarction (MI) prior to the crash. Which laboratory test result drawn while the patient was in the emergency department would the nurse evaluate as supporting that theory?
1. Increased serum potassium
2. Increased creatine kinase level
3. Increased BNP level
4. Increased troponin level
Answer: 4
Explanation: 1. Potassium level changes may indicate damage to muscle tissue, but is not specific to heart muscle.
2. Creatine kinase levels do not rise until 4 to 12 hours after onset of myocardial necrosis. Unless a CK-MB level was drawn, the CK level is not specific to cardiac muscle.
3. BNP level is assessed for the presence of heart failure.
4. Troponin is a protein found in cardiac muscle and can appear in the blood as early as 1 to 3 hours after symptoms of MI. Troponin has a higher sensitivity and specificity of identifying myocardial damage than does creatine kinase.
13) The nurse is instructing a patient who is scheduled for a cardiac catheterization. Which comment made by the patient would indicate the need for additional education?
1. “The nurse will check my feet very often after the procedure.”
2. “I will place a warm pack at the puncture site for pain relief.”
3. “I should let the nurse know if I need to cough after the procedure is done.”
4. “I will have someone available to drive me home following the procedure.”
Answer: 2
Explanation: 1. Pedal pulses are checked bilaterally after the procedure.
2. The vasodilatory effect of a warm pack would cause vessel rupture and, therefore, is the choice that indicates a need for further education.
3. To minimize stress on the insertion site, it should be manually compressed when the patient coughs.
4. Many of these procedures are done as outpatient procedures, which would require someone to drive the patient home.
14) A patient admitted with a cardiac arrhythmia is scheduled to have an electrophysiology study (EPS). The nurse would reinforce which teaching about this test?
1. This test will be helpful in determining if you need a pacemaker.
2. This test will help us determine how your heart responds to stress.
3. We can learn about the strength of your heart valves with this test.
4. This test will reveal the health of your heart’s blood supply system
Answer: 1
Explanation: 1. The electrophysiology study is an invasive procedure that evaluates the cardiac conduction system and helps classify cardiac arrhythmias. The findings from this study help to determine if the patient would benefit from further interventions such as a pacemaker, implantable cardiodefibrillator, and radiofrequency ablation or medication therapy.
2. Exercise electrocardiograms evaluate heart muscle and its blood supply during physical stress.
3. Echocardiograms are used to visualize blood, cardiac valves, the myocardium, and the pericardium.
4. Cardiac catheterization is performed to determine the presence and extent of coronary artery disease, evaluate left ventricular function, and to evaluate valvular or myocardial disorders.
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15) A patient is scheduled for an exercise electrocardiogram. The nurse will ensure that which objects are in the room prior to the beginning of the test?
1. Oral fluids
2. A defibrillator
3. External pacemaker
4. Portable chest x-ray machine
Answer: 2
Explanation: 1. There is no reason that oral fluids are required for this test.
2. Emergency medications and a defibrillator should be present in the room during an exercise electrocardiogram test. The patient may respond poorly to the stress placed on the heart during exercise and may require an emergency response with this equipment.
3. There is no specific indication that it is necessary to have an external pacemaker present when this testing is taking place.
4. There is no reason for a portable x-ray machine to be present in the room during this test.
