Chapter 21: Assessment of Cardiovascular Function

13. The nurse working on a cardiac care unit is caring for a client whose stroke volume has increased. The nurse is aware that afterload influences a client's stroke volume. The nurse recognizes that which factor increases afterload? A. Arterial vasoconstriction B. Venous vasoconstriction C. Arterial vasodilation D. Venous vasodilation

ANS: A Rationale: Afterload, or resistance to ejection of blood from the ventricle, is one determinant of stroke volume. There is an inverse relationship between afterload and stroke volume. Arterial vasoconstriction increases afterload, which leads to decreased stroke volume. Conversely, arterial vasodilation decreases afterload because there is less resistance to ejection, and stroke volume increases. Preload, or the degree of stretch of the ventricular cardiac muscle fibers at the end of diastole, is another determinant of stroke volume. There is a direct relationship between preload and stroke volume. Venous vasoconstriction increases preload, which leads to increased stroke volume. Conversely, venous vasodilation decreases preload, which leads to decreased stroke volume. Because the ventricles only eject blood into arteries, not veins, afterload is only affected by arterial, not venous, vasoconstriction and vasodilation. Because the ventricles only receive blood from veins, not arteries, preload is only affected by venous, not arterial, vasoconstriction and vasodilation.

28. A client with a complex cardiac history is scheduled for transthoracic echocardiography. What should the nurse teach the client in anticipation of this diagnostic procedure? A. The test is noninvasive, and nothing will be inserted into the client's body. B. The client's pain will be managed aggressively during the procedure. C. The test will provide a detailed profile of the heart's electrical activity. D. The client will remain on bed rest for 1 to 2 hours after the test.

ANS: A Rationale: Before transthoracic echocardiography, the nurse informs the client about the test, explaining that it is painless. The test does not evaluate electrophysiology, and bed rest is unnecessary after the procedure.

4. A client has been admitted to the intensive care unit (ICU) after an ischemic stroke, and a central venous pressure (CVP) monitoring line was placed. The nurse notes a low CVP. Which condition is the most likely reason for a low CVP? A. Hypovolemia B. Myocardial infarction (MI) C. Left-sided heart failure D. Aortic valve regurgitation

ANS: A Rationale: CVP is a measurement of the pressure in the vena cava or right atrium. A low CVP indicates a reduced right ventricular preload, most often from hypovolemia. An MI is an unlikely cause of low CVP. CVP measures the right side of the heart, so left-sided failure is unlikely to affect CVP. Aortic valve regurgitation is a less likely cause of low CVP

15. The nurse is caring for a client admitted with angina who is scheduled for cardiac catheterization. The client is anxious and asks the reason for this test. The nurse should explain that cardiac catheterization is most commonly done for which purpose? A. To assess how blocked or open a client's coronary arteries are B. To detect how efficiently a client's heart muscle contracts C. To evaluate cardiovascular response to stress D. To evaluate cardiac electrical activity

ANS: A Rationale: Cardiac catheterization is usually used to assess coronary artery patency to determine whether revascularization procedures are necessary. A thallium stress test shows myocardial ischemia after stress. An ECG shows the electrical activity of the heart.

36. The nurse is conducting client teaching about cholesterol levels. When discussing the client's elevated LDL and lowered HDL levels, the client shows an understanding of the significance of these levels by making what statement? A. "Increased LDL and decreased HDL increase my risk of coronary artery disease." B. "Increased LDL has the potential to decrease my risk of heart disease." C. "The decreased HDL level will increase the amount of cholesterol moved away from the artery walls." D. "The increased LDL will decrease the amount of cholesterol deposited on the artery walls."

ANS: A Rationale: Elevated LDL levels and decreased HDL levels are associated with a greater incidence of coronary artery disease.

10. The critical care nurse is caring for a client with a pulmonary artery pressure monitoring system. In addition to assessing left ventricular function, what is an additional function of a pulmonary artery pressure monitoring system? A. To assess the client's response to fluid and drug administration B. To obtain specimens for arterial blood gas measurements C. To dislodge pulmonary emboli D. To diagnose the etiology of chronic obstructive pulmonary disease

ANS: A Rationale: Pulmonary artery pressure monitoring is an important tool used in critical care for assessing left ventricular function (cardiac output), diagnosing the etiology of shock, and evaluating the client's response to medical interventions, such as fluid administration and vasoactive medications. Pulmonary artery monitoring is preferred over central venous pressure monitoring for the client with heart failure. Arterial catheters are useful when arterial blood gas measurements and blood samples need to be obtained frequently. Neither intervention is used to clear pulmonary emboli.

3. The nurse is calculating a cardiac client's pulse pressure. If the client's blood pressure is 122/76 mm Hg, what is the client's pulse pressure? A. 46 mm Hg B. 99 mm Hg C. 198 mm Hg D. 76 mm Hg

ANS: A Rationale: Pulse pressure is the difference between the systolic and diastolic pressure. In this case, this value is 46 mm Hg.

1. A nurse is describing the process by which blood is ejected into circulation as the chambers of the heart become smaller. The instructor categorizes this as what action? A. Systole B. Diastole C. Repolarization D. Ejection fraction

ANS: A Rationale: Systole is the action of the chambers of the heart becoming smaller and ejecting blood. This action of the heart is not diastole (relaxation), ejection fraction (the amount of blood expelled), or repolarization (electrical charging).

24. The critical care nurse is caring for a client who has been experiencing bradycardia after cardiovascular surgery. The nurse knows that the heart rate is determined by myocardial cells with the fastest inherent firing rate. Under normal circumstances where are these cells located? A. SA node B. AV node C. Bundle of His D. Purkinje cells

ANS: A Rationale: The heart rate is determined by the myocardial cells with the fastest inherent firing rate. Under normal circumstances, the SA node has the highest inherent rate (60 to 100 impulses per minute).

32. A client's declining cardiac status has been attributed to decreased cardiac action potential. Interventions should be aimed at restoring what aspect of cardiac physiology? A. The cycle of depolarization and repolarization B. The time it takes from the firing of the SA node to the contraction of the ventricles C. The time between the contraction of the atria and the contraction of the ventricles D. The cycle of the firing of the AV node and the contraction of the myocardium

ANS: A Rationale: This exchange of ions creates a positively charged intracellular space and a negatively charged extracellular space that characterizes the period known as depolarization. Once depolarization is complete, the exchange of ions reverts to its resting state; this period is known as repolarization. The repeated cycle of depolarization and repolarization is called the cardiac action potential.

23. When hemodynamic monitoring is ordered for a client, a catheter is inserted into the appropriate blood vessel or heart chamber. When assessing a client who has such a device in place, the nurse should check which of the following components? Select all that apply. A. A transducer B. A flush system C. A leveler D. A pressure bag E. An oscillator

ANS: A, B, D Rationale: To perform hemodynamic monitoring, a CVP, pulmonary artery, or arterial catheter is introduced into the appropriate blood vessel or heart chamber. It is connected to a pressure monitoring system that has several components. Included among these are a transducer, a flush system, and a pressure bag. A pressure monitoring system does not have a leveler or an oscillator.

29. A critical care nurse is caring for a client with a hemodynamic monitoring system in place. For what complications should the nurse assess? Select all that apply. A. Pneumothorax B. Infection C. Atelectasis D. Bronchospasm E. Air embolism

ANS: A, B, E Rationale: Complications from use of hemodynamic monitoring systems are uncommon, but can include pneumothorax, infection, and air embolism. Complications of hemodynamic monitoring systems do not include atelectasis or bronchospasm.

27. The client has a homocysteine level ordered. What aspects of this test should inform the nurse's care? Select all that apply. A. A 12-hour fast is necessary before drawing the blood sample. B. Recent inactivity can depress homocysteine levels. C. Genetic factors can elevate homocysteine levels. D. A diet low in folic acid elevates homocysteine levels. E. An ECG should be performed immediately before drawing a sample.

ANS: A, C, D Rationale: Genetic factors and a diet low in folic acid, vitamin B6, and vitamin B12 are associated with elevated homocysteine levels. A 12-hour fast is necessary before drawing a blood sample for an accurate serum measurement. An ECG is unnecessary and recent inactivity does not influence the results of the test.

33. A client has been scheduled for cardiovascular computed tomography (CT) with contrast. To prepare the client for this test, what action should the nurse perform? A. Keep the client NPO for at least 6 hours prior to the test. B. Establish peripheral IV access. C. Limit the client's activity for 2 hours before the test. D. Teach the client to perform incentive spirometry.

ANS: B Rationale: An IV is necessary if contrast is to be used to enhance the images of the CT. The client does not need to fast or limit activity. Incentive spirometry is not relevant to this diagnostic test.

25. The nurse is doing discharge teaching with a client who has coronary artery disease. The client asks why they have to take an aspirin every day if they don't have any pain. Which rationale for this intervention would be the best? A. To help restore the normal function of the heart B. To help prevent blockages that can cause chest pain or heart attacks C. To help the blood penetrate the heart more freely D. To help the blood carry more oxygen than it would otherwise

ANS: B Rationale: An aspirin a day is a common nonprescription medication that improves outcomes in clients with coronary artery disease due to its antiplatelet action, which helps to prevent clots that can lead to chest pain or heart attacks. It does not affect oxygen-carrying capacity or perfusion. Aspirin does not restore cardiac function.

9. The critical care nurse is caring for a client with a central venous pressure (CVP) monitoring system. The nurse notes that the client's CVP is increasing. This may indicate: A. psychosocial stress. B. hypervolemia. C. dislodgment of the catheter. D. hypomagnesemia.

ANS: B Rationale: CVP is a useful hemodynamic parameter to observe when managing an unstable client's fluid volume status. An increasing pressure may be caused by hypervolemia or by a condition, such as heart failure, that results in decreased myocardial contractility. Stress, dislodgment of the catheter, and low magnesium levels would not typically result in increased CVP.

7. The nurse is caring for a client who has a history of heart disease. What factor should the nurse identify as possibly contributing to a decrease in cardiac output? A. A change in position from standing to sitting B. A heart rate of 54 bpm C. A pulse oximetry reading of 94% D. An increase in preload related to ambulation

ANS: B Rationale: Cardiac output is computed by multiplying the stroke volume by the heart rate. Cardiac output can be affected by changes in either stroke volume or heart rate, such as a rate of 54 bpm. An increase in preload will lead to an increase in stroke volume. A pulse oximetry reading of 94% does not indicate hypoxemia, as hypoxia can decrease contractility. Transitioning from standing to sitting would more likely increase rather than decrease cardiac output.

37. A resident of a long-term care facility has reported chest pain to the nurse. What aspect of the resident's pain would be most suggestive of angina as the cause? A. The pain is worse when the resident inhales deeply. B. The pain occurs immediately following physical exertion. C. The pain is worse when the resident coughs. D. The pain is most severe when the resident moves the upper body.

ANS: B Rationale: Chest pain associated with angina is often precipitated by physical exertion. The other listed aspects of chest pain are more closely associated with noncardiac etiologies.

17. The nurse is caring for an acutely ill client who has central venous pressure monitoring in place. What intervention should be included in the care plan of a client with CVP in place? A. Apply antibiotic ointment to the insertion site twice daily. B. Change the site dressing whenever it becomes visibly soiled. C. Perform passive range-of-motion exercises to prevent venous stasis. D. Aspirate blood from the device once daily to test pH.

ANS: B Rationale: Gauze dressings should be changed every 2 days or transparent dressings at least every 7 days and whenever dressings become damp, loosened, or visibly soiled. Passive ROM exercise is not indicated and it is unnecessary and inappropriate to aspirate blood to test it for pH. Antibiotic ointments are contraindicated.

26. The health care provider has ordered a high-sensitivity C-reactive protein (hs-CRP) drawn on a client. The results of this test will allow the nurse to evaluate the role of what process that is implicated in the development of atherosclerosis? A. Immunosuppression B. Inflammation C. Infection D. Hemostasis

ANS: B Rationale: High-sensitivity CRP is a protein produced by the liver in response to systemic inflammation. Inflammation is thought to play a role in the development and progression of atherosclerosis.

20. The nurse's assessment of an older adult client reveals the following data: Lying BP 144/82 mm Hg; sitting BP 121/69 mm Hg; standing BP 98/56 mm Hg. The nurse should identify the priority nursing diagnosis of a risk for which outcome in the client's plan of care? A. Ineffective breathing pattern related to hypotension B. Falls related to orthostatic hypotension C. Ineffective role performance related to hypotension D. Imbalanced fluid balance related to hemodynamic variability

ANS: B Rationale: Orthostatic hypotension creates a significant risk for falls due to the dizziness and lightheadedness that accompany it. It does not normally affect breathing or fluid balance. The client's ability to perform normal roles may be affected, but the risk for falls is the most significant threat to safety.

16. The critical care nurse is caring for a client who has had an MI. The nurse should expect to assist with establishing what hemodynamic monitoring procedure to assess the client's left ventricular function? A. Central venous pressure (CVP) monitoring B. Pulmonary artery pressure monitoring (PAPM) C. Systemic arterial pressure monitoring (SAPM) D. Arterial blood gases (ABGs)

ANS: B Rationale: Pulmonary artery pressure monitoring is used to assess left ventricular function. CVP is used to assess right ventricular function; systemic arterial pressure monitoring is used for continual assessment of BP. ABGs are used to assess for acidic and alkalotic levels in the blood.

5. While auscultating a client's heart sounds, the nurse hears an extra heart sound immediately after the second heart sound (S2). An audible S3 would be considered an expected finding in which client? A. A 47-year-old client B. A 20-year-old client C. A client who has undergone valve replacement D. A client who takes a beta-adrenergic blocker

ANS: B Rationale: S3 represents a normal finding in children and adults up to 35 or 40 years of age. In these cases, it is called a physiologic S3. It is an abnormal finding in a client with an artificial valve, an adult older than 40 years of age, or a client who takes a beta blocker.

2. During a shift assessment, the nurse is identifying the client's point of maximum impulse (PMI). Where should the nurse best palpate the PMI? A. Left midclavicular line of the chest at the level of the nipple B. Left midclavicular line of the chest at the fifth intercostal space C. Midline between the xiphoid process and the left nipple D. Two to three centimeters to the left of the sternum

ANS: B Rationale: The left ventricle is responsible for the apical beat or the point of maximum impulse, which is normally palpated in the left midclavicular line of the chest wall at the fifth intercostal space.

21. A brain (B-type) natriuretic peptide (BNP) sample has been drawn from an older adult client who has been experiencing vital fatigue and shortness of breath. This test will allow the care team to investigate the possibility of what diagnosis? A. Pleurisy B. Heart failure C. Valve dysfunction D. Cardiomyopathy

ANS: B Rationale: The level of BNP in the blood increases as the ventricular walls expand from increased pressure, making it a helpful diagnostic, monitoring, and prognostic tool in the setting of HF. It is not specific to cardiomyopathy, pleurisy, or valve dysfunction.

6. The physical therapist notifies the nurse that a client with coronary artery disease (CAD) experienced a significant increase in heart rate during physical therapy. The nurse recognizes that an increase in heart rate in a client with CAD may result in which outcome? A. Development of an atrial-septal defect B. Myocardial ischemia C. Formation of a pulmonary embolism D. Release of potassium ions from cardiac cells

ANS: B Rationale: Unlike other arteries, the coronary arteries are perfused during diastole. An increase in heart rate shortens diastole and can decrease myocardial perfusion. Clients, particularly those with CAD, can develop myocardial ischemia. An increase in heart rate will not usually result in a pulmonary embolism or create electrolyte imbalances. Atrial-septal defects are congenital.

19. The nurse is relating the deficits in a client's synchronization of the atrial and ventricular events to his diagnosis. What are the physiologic characteristics of the nodal and Purkinje cells that provide this synchronization? Select all that apply. A. Loop connectivity B. Excitability C. Automaticity D. Conductivity E. Independence

ANS: B, C, D Rationale: Three physiologic characteristics of two types of specialized electrical cells, the nodal cells and the Purkinje cells, provide this synchronization: automaticity, or the ability to initiate an electrical impulse; excitability, or the ability to respond to an electrical impulse; and conductivity, the ability to transmit an electrical impulse from one cell to another. Loop connectivity is a distracter for this question. Independence of the cells has nothing to do with the synchronization described in the scenario.

22. A lipid profile has been ordered for a client who has been experiencing cardiac symptoms. When should a lipid profile be drawn in order to maximize the accuracy of results? A. As close to the end of the day as possible B. After a meal high in fat C. After a 12-hour fast D. Thirty minutes after a normal meal

ANS: C Rationale: Although cholesterol levels remain relatively constant over 24 hours, the blood specimen for the lipid profile should be obtained after a 12-hour fast.

38. The nurse is performing an intake assessment on a client with a new diagnosis of coronary artery disease. What would be the most important determination to make during this intake assessment? A. Whether the client and involved family members understand the role of genetics in the etiology of the disease B. Whether the client and involved family members understand dietary changes and the role of nutrition C. Whether the client and involved family members are able to recognize symptoms of an acute cardiac problem and respond appropriately D. Whether the client and involved family members understand the importance of social support and community agencies

ANS: C Rationale: During the health history, the nurse needs to determine if the client and involved family members are able to recognize symptoms of an acute cardiac problem, such as acute coronary syndrome (ACS) or HF, and seek timely treatment for these symptoms. Each of the other listed topics is valid, but the timely and appropriate response to a cardiac emergency is paramount.

14. A nurse is preparing a client for scheduled transesophageal echocardiography. Which action should the nurse perform? A. Instruct the client to drink 1 L of water before the test. B. Administer intravenous (IV) benzodiazepines and opioids. C. Inform the client that the client will remain on bed rest following the procedure. D. Inform the client that an access line will be initiated in the femoral artery.

ANS: C Rationale: During the recovery period, the client must maintain bed rest with the head of the bed elevated to 45 degrees. The client must be NPO 6 hours pre-procedure. The client is sedated to make the client comfortable, but the client will not be heavily sedated and opioids are not necessary. Also, the client will have a peripheral IV line initiated pre-procedure

12. A client has had a myocardial infarction and has been diagnosed as having damage to the layer of the heart responsible for the pumping action. This client experienced damage to which area of the heart? A. Endocardium B. Pericardium C. Myocardium D. Visceral pericardium

ANS: C Rationale: The middle layer of the heart, or myocardium, is made up of muscle fibers and is responsible for the pumping action. The inner layer, or endocardium, consists of endothelial tissue and lines the inside of the heart and valves. The heart is encased in a thin, fibrous sac called the pericardium, which is composed of two layers. Adhering to the epicardium is the visceral pericardium. Enveloping the visceral pericardium is the parietal pericardium, a tough fibrous tissue that attaches to the great vessels, diaphragm, sternum, and vertebral column and supports the heart in the mediastinum.

30. The nurse is caring for a client who has central venous pressure (CVP) monitoring in place. The nurse's most recent assessment reveals that CVP is 7 mm Hg. What is the nurse's most appropriate action? A. Arrange for continuous cardiac monitoring and reposition the client. B. Remove the CVP catheter and apply an occlusive dressing. C. Assess the client for fluid overload and inform the health care provider. D. Raise the head of the client's bed and have the client perform deep breathing exercises, if possible.

ANS: C Rationale: The normal CVP is 2 to 6 mm Hg. Many problems can cause an elevated CVP, but the most common is due to hypervolemia. Assessing the client and informing the health care provider are the most prudent actions. Repositioning the client is ineffective and removing the device is inappropriate.

35. The nurse is caring for a client admitted with unstable angina. The laboratory result for the initial troponin I is elevated in this client. The nurse should recognize what implication of this assessment finding? A. This is only an accurate indicator of myocardial damage when it reaches its peak in 24 hours. B. Because the client has a history of unstable angina, this is a poor indicator of myocardial injury. C. This is an accurate indicator of myocardial injury. D. This result indicates muscle injury, but does not specify the source.

ANS: C Rationale: Troponin I, which is specific to cardiac muscle, is elevated within hours after myocardial injury. Even with a diagnosis of unstable angina, this is an accurate indicator of myocardial injury.

31. A critical care nurse is caring for a client with a pulmonary artery catheter in place. What does this catheter measure that is particularly important in critically ill clients? A. Pulmonary artery systolic pressure B. Right ventricular afterload C. Pulmonary artery pressure D. Left ventricular preload

ANS: D Rationale: Monitoring of the pulmonary artery diastolic and pulmonary artery wedge pressures is particularly important in critically ill clients because it is used to evaluate left ventricular filling pressures (i.e., left ventricular preload). This device does not directly measure the other listed aspects of cardiac function.

8. A client is admitted to a cardiac unit with the diagnosis of syncope. Orthostatic blood pressures are ordered every 8 hours. Which blood pressure readings would best indicate that the nurse should notify the health care provider of a positive finding? A. Supine 146/70 mm Hg, sitting 132/68 mm Hg, standing 130/66 mm Hg B. Supine 110/62 mm Hg, sitting 108/58 mm Hg, standing 106/56 mm Hg C. Supine 128/72 mm Hg, sitting 118/70 mm Hg, standing 110/66 mm Hg D. Supine 138/76 mm Hg, sitting 132/66 mm Hg, standing 122/52 mm Hg

ANS: D Rationale: Postural (orthostatic) hypotension is a significant drop in blood pressure (20 mm Hg systolic or more or 10 mm Hg diastolic or more) within 3 minutes of moving from a lying or sitting to a standing position to indicate a positive result.

34. The nurse is caring for a client who is undergoing an exercise stress test. Prior to reaching the target heart rate, the client develops chest pain. What is the nurse's most appropriate response? A. Administer sublingual nitroglycerin to allow the client to finish the test. B. Initiate cardiopulmonary resuscitation. C. Administer analgesia and slow the test. D. Stop the test and monitor the client closely.

ANS: D Rationale: The client may be experiencing signs of myocardial ischemia would necessitate stopping the test. CPR would only be necessary if signs of cardiac or respiratory arrest were evident. The client should not be permitted to continue the test due to risk of MI, therefore the first option, administer nitroglycerin is incorrect. The nurse would not administer pain medication and slow the test as this could mask the symptoms of MI and the client should not be permitted to continue with the test. Further assessment by the nurses must be completed and protocol for MI initiated.

11. The cardiac care nurse is reviewing the conduction system of the heart. The nurse is aware that electrical conduction of the heart usually originates in the sinoatrial (SA) node and then proceeds in which sequence? A. Bundle of His to atrioventricular (AV) node to Purkinje fibers B. AV node to Purkinje fibers to bundle of His C. Bundle of His to Purkinje fibers to AV node D. AV node to bundle of His to Purkinje fibers

ANS: D Rationale: The normal electrophysiological conduction route is SA node to AV node to bundle of His to Purkinje fibers.

18. A client is brought into the emergency department (ED) by family members, who tell the nurse the client grabbed their chest and reported substernal chest pain. The care team recognizes the need to monitor the client's cardiac function closely while interventions are performed. Which form of monitoring should the nurse anticipate? A. Left-sided heart catheterization B. Cardiac telemetry C. Transesophageal echocardiography D. Hardwire continuous electrocardiogram (ECG) monitoring

ANS: D Rationale: Two types of continuous ECG monitoring techniques are used in health care settings: hardwire cardiac monitoring, found in EDs, critical care units, and progressive care units; and telemetry, found in general nursing care units or outpatient cardiac rehabilitation programs. Cardiac catheterization and transesophageal echocardiography would not be used in emergent situations to monitor cardiac function.