Chapter 31 Assessment of Cardiovascular System Flashcards
1
Q
The heart ♣ Has four chambers: ♣ Is composed of three layers: o Is surrounded by a? o Has four valves:
A
♣ Has four chambers: the right and left atrium and right and left ventricles.
♣ Is composed of three layers: endocardium (thin inner lining), myocardium (layer of muscle), and epicardium (outer layer).
o Is surrounded by a fibroserous sac called the pericardium.
o Has four valves: mitral, aortic, tricuspid, and pulmonary. These maintain the one-way flow of blood.
2
Q
Heart: The thickness of the wall of each chamber is different. The atrial myocardium is thinner than that of the ventricles, and the left ventricular wall is two or three times thicker than the right ventricular wall. The thickness of the left ventricle is necessary to?
A
produce the force needed to pump the blood into the systemic circulation.
3
Q
Blood flow:
A
1, The right atrium receives venous blood from the inferior and superior venae cavae and the coronary sinus. The blood then passes through the tricuspid valve into the right ventricle.
2, With each contraction, the right ventricle pumps blood through the pulmonic valve into the pulmonary artery and to the lungs.
3, Oxygenated blood flows from the lungs to the left atrium by way of the pulmonary veins.
4, It then passes through the mitral valve and into the left ventricle.
5, As the heart contracts, blood is ejected through the aortic valve into the aorta and thus enters the systemic circulation.
4
Q
The right side of the heart receives venous blood from the body (via the vena cava) and pumps it to the lungs where it is oxygenated. Blood returns to the?
A
left side of the heart (via the pulmonary veins) and is pumped to the body via the aorta.
5
Q
The pulmonic and aortic valves (also known as semilunar valves) prevent blood from?.
A
regurgitating into the ventricles at the end of each ventricular contraction.
6
Q
Blood supply to myocardium: The myocardium has its own blood supply, the coronary circulation. Blood flow into the two major coronary arteries occurs primarily during diastole (relaxation of the myocardium). The left coronary artery arises from the aorta and divides into two main branches: the left anterior descending artery and left circumflex artery. These arteries supply the left atrium, left ventricle, interventricular septum, and a portion of the right ventricle. The right coronary artery also arises from the aorta, and its branches supply the right atrium, right ventricle, and a portion of the posterior wall of the left ventricle. In 90% of people the atrioventricular (AV) node and the bundle of His receive blood supply from the?
A
right coronary artery. For this reason, blockage of this artery often causes serious defects in cardiac conduction.
7
Q
Blood flow into the two major coronary arteries occurs primarily during?
A
diastole (relaxation of the myocardium)
8
Q
Blood supply to myocardium: The divisions of coronary veins parallel the coronary arteries. Most of the blood from the coronary system drains into the?
A
coronary sinus (a large channel), which empties into the right atrium near the entrance of the inferior vena cava.
9
Q
Conduction system: consists of specialized tissue responsible for creating and transporting electrical impulse (action potential). This impulse starts depolarization of the heart cells and subsequently heart contraction. The electrical impulse begins in the?
A
1) sinoatrial (SA) node (pacemaker of the heart). Each impulse coming from SA node travels through interatrial pathways to depolarize the atria, resulting in a contraction.
2) electrical impulse travels from atria to AV node through internodal pathways.
3) signal then moves through bundle of His and left and right bundle branches. left bundle branch has two fascicles (divisions): anterior and posterior. action potential moves through walls of both ventricles by means of Purkinje fibers.
4) ventricular conduction system delivers the impulse within 0.12 second. This triggers a synchronized right and left ventricular contraction and ejection of blood into the pulmonary and systemic circulations.
5) repolarization occurs when contractile fiber cells and conduction pathway cells regain resting polarized condition. Heart muscle cells have a compensatory mechanism that makes them unresponsive or refractory to restimulation during the action potential. During ventricular contraction, there is an absolute refractory period during which heart muscle does not respond to any stimuli. After this period, heart muscle gradually recovers its excitability, and a relative refractory period occurs by early diastole.
10
Q
The coronary circulation provides blood to the myocardium (heart muscle). The right and left coronary arteries are the?
A
first two branches off the aorta.
11
Q
The conduction system consists of specialized cells that create and transport electrical impulses. These electrical impulses initiate?
A
depolarization of the myocardium. This triggers a cardiac contraction.
12
Q
Each electrical impulse starts at the?
A
SA node (located in the right atrium), travels to the AV node (located at the atrioventricular junction), through the bundle of His, down the right and left bundle branches (located in the ventricular septum), and ends in the Purkinje fibers.
13
Q
Electrocardiogram: The letters P, QRS, T, and U are used to identify the separate waveforms.
A
1) P wave, begins with the firing of the SA node and represents depolarization of the atria.
2) The QRS complex represents depolarization from the AV node throughout the ventricles.
* There is a delay of impulse transmission through the AV node that accounts for the time between the beginning of the P wave and the beginning of the QRS wave.
3) The T wave represents repolarization of the ventricles. 4) The U wave, if seen, may represent repolarization of the Purkinje fibers, or it may be associated with hypokalemia.
14
Q
Electrocardiogram: Intervals between these waves (PR, QRS, and QT intervals) reflect the time it takes for the signal to travel from one area of the heart to another. These time intervals are?
A
measured, and changes from these time references often indicate pathologic conditions
15
Q
Mechanical System.
Depolarization triggers mechanical activity.
1) Systole, contraction of the heart muscle, results in?
2) Relaxation of the heart muscle, diastole, allows for?
3) Cardiac output (CO), the amount of?
A
1) ejection of blood from the ventricles.
2) filling of the ventricles.
3) blood pumped by each ventricle in 1 minute, is calculated by multiplying the amount of blood ejected from the ventricle with each heartbeat: stroke volume (SV) times heart rate (HR) per minute: CO = SV x HR
16
Q
1) For the normal adult at rest, CO is maintained in the range of?
2) Cardiac index (CI) is the?
3) The CI adjusts the CO to the body size. The normal CI is?
A
1) 4 to 8 L/min
2) CO divided by the body surface area (BSA).
3) 2.8 to 4.2 L per minute per meter squared (L/min/m2)
17
Q
Amount of blood ejected with each heart beat
A
Stroke volume
18
Q
Amount of blood pumped by each ventricle in 1 minute
Normal:
A
Cardiac output: Amount of blood pumped by each ventricle in 1 minute
Normal 4-8 L/min
19
Q
Cardiac index:
Normal:
A
Cardiac index: CO divided by body surface area
Normal 2.8-4.2 L/min/m2
20
Q
Factors Affecting Cardiac Output.
Numerous factors can affect either the HR or SV, and thus the CO. The HR, which is controlled primarily by the autonomic nervous system, can reach as high as 180 beats/min for short periods without harmful effects. The factors affecting the SV are?
A
preload, contractility, and afterload. Increasing preload, contractility, and afterload increases the workload of the heart muscle, resulting in increased O2 demand.
21
Q
Frank-Starling law states that, to a point, the more the myocardial fibers are stretched, the greater their force of contraction. The volume of blood in the ventricles at the end of diastole, before the next contraction, is called preload. Preload determines the amount of?
A
stretch placed on myocardial fibers. Preload can be increased by a number of conditions such as hypertension, aortic valve disease, and hypervolemia
22
Q
Factors affecting cardiac output: Contractility can be increased by?
A
epinephrine and norepinephrine released by the sympathetic nervous system. Increasing contractility raises the SV by increasing ventricular emptying.
23
Q
Factors affecting cardiac output:
1) Afterload is the?
2) Afterload is affected by the?
A
1) peripheral resistance against which the left ventricle must pump.
2) size of the ventricle, wall tension, and arterial blood pressure (BP). If the arterial BP is elevated, the ventricles meet increased resistance to ejection of blood, increasing the work demand. Eventually this results in ventricular hypertrophy, an enlargement of the heart muscle without an increase in CO or the size of chambers
24
Q
Factors Affecting Cardiac Output
A
1) Preload: Volume of blood in ventricles at the end of diastole
2) Contractility
3) Afterload: Peripheral resistance against which the left ventricle must pump
25
```
A patient is receiving a drug that decreases afterload. To evaluate the patient's response to this drug, what is most important for the nurse to assess?
A. Heart rate
B. Lung sounds
C. Blood pressure
D. Jugular venous distention
```
C. Blood pressure (trying to reduce afterload so we must reduce BP)
26
The cardiovascular system must respond to numerous situations in health and illness (e.g., exercise, stress, hypovolemia). The ability to respond to these demands by altering CO is termed?
cardiac reserve
27
Factors affecting SV are preload, contractility, and afterload.
- Preload is the volume of blood in the ventricles at the end of diastole
- afterload represents the systemic resistance against which the left ventricle must pump.
28
Blood Vessels.
| The three major types of blood vessels in the vascular system are the arteries, veins, and capillaries.
- Arteries, except for the pulmonary artery, carry oxygenated blood away from the heart.
- Veins, except for the pulmonary veins, carry deoxygenated blood toward the heart.
- Small branches of arteries and veins are arterioles and venules.
- Blood circulates from the left side of the heart into arteries, arterioles, capillaries, venules, and veins, and then back to the right side of the heart.
29
Heart structure: The arterial system differs from the venous system by the amount and type of tissue that make up arterial walls. The large arteries have thick walls composed mainly of elastic tissue. This elastic property cushions the impact of the pressure created by ventricular contraction and provides recoil that propels blood forward into the circulation. Large arteries also contain some?
smooth muscle. Examples of large arteries are the aorta and pulmonary artery.
30
Arterioles have relatively little elastic tissue and more smooth muscle. Arterioles serve as the major control of?
arterial BP and distribution of blood flow. They respond readily to local conditions such as low O2 and increasing levels of CO2 by dilating or constricting.
31
The innermost lining of the arteries is the endothelium. The endothelium maintains hemostasis, promotes blood flow, and, under normal conditions, inhibits blood coagulation. When the endothelial surface is disrupted what happens?
(e.g., rupture of an atherosclerotic plaque), the coagulation cascade is initiated and results in the formation of a fibrin clot.
32
Capillaries.
| The thin capillary wall, made up of endothelial cells, has no elastic or muscle tissue. The exchange of cellular?
nutrients and metabolic end products takes place through these thin-walled vessels. Capillaries connect the arterioles and venules.
33
Heart structure: Veins are large-diameter, thin-walled vessels that return blood to the right atrium.
1) The venous system is a?
2) The larger veins contain semilunar valves at intervals to maintain the?
3) The amount of blood in the venous system is affected by a number of factors, including?
1) low-pressure, high-volume system.
2) blood flow toward the heart and to prevent backward flow.
3) arterial flow, compression of veins by skeletal muscles, alterations in thoracic and abdominal pressures, and right atrial pressure.
34
The largest veins are the superior vena cava, which returns blood to the heart from the head, neck, and arms, and the inferior vena cava, which returns blood to the heart from the lower part of the body. These large-diameter vessels are affected by the?
pressure in the right side of the heart. Elevated right atrial pressure can cause distended neck veins or liver engorgement as a result of resistance to blood flow.
35
Venules are relatively small vessels made up of a small amount of?
muscle and connective tissue. Venules collect blood from the capillary beds and channel it to the larger veins.
36
Regulation of the cardiovascular system
1) Autonomic nervous system
- Sympathetic
- Parasympathetic
2) Baroreceptors
3) Chemoreceptors
37
Effect on Heart.
| Stimulation of the sympathetic nervous system increases?
HR, speed of impulse conduction through the AV node, and force of atrial and ventricular contractions. This effect is mediated by specific sites in the heart called beta (β)-adrenergic receptors, which are receptors for norepinephrine and epinephrine.
38
Effect on heart: stimulation of the parasympathetic system (mediated by the vagus nerve) does what?
slows the HR by decreasing the impulses from the SA node and thus conduction through the AV node.
39
Effect on Blood Vessels.
The source of neural control of blood vessels is the sympathetic nervous system. The alpha1 (α1)-adrenergic receptors are located in?
vascular smooth muscles. Stimulation of α1-adrenergic receptors results in vasoconstriction. Decreased stimulation to α1-adrenergic receptors causes vasodilation.
40
Effect on blood vessels: The parasympathetic nerves have selective?
distribution in the blood vessels. For example, blood vessels in skeletal muscle do not receive parasympathetic input.
41
Baroreceptors in the aortic arch and carotid sinus (at the origin of the internal carotid artery) are sensitive to?
2) Stimulation of these receptors (e.g., volume overload) sends information to the vasomotor center in the brainstem. This results in temporary?
3) Decreased arterial pressure causes?
1) sensitive to stretch or pressure within the arterial system.
2) inhibition of the sympathetic nervous system and enhancement of the parasympathetic influence, causing a decreased HR and peripheral vasodilation.
3) the opposite effect.
42
Chemoreceptors are located in the aortic and carotid bodies and the medulla. They are capable of causing changes in?
- When the chemoreceptors in the medulla are triggered, they?
- changes in respiratory rate and BP in response to increased arterial CO2 pressure (hypercapnia) and, to a lesser degree, decreased plasma pH (acidosis) and arterial O2 pressure (hypoxia).
- stimulate the vasomotor center to increase BP
43
Stimulation of baroreceptors and chemoreceptors, located in the aortic arch and carotid sinus, can initiate changes in?
HR and arterial pressure
44
Blood Pressure
1) The arterial blood pressure is a measure of the?
2) The systolic blood pressure (SBP) is the?
3) The diastolic blood pressure (DBP) is the?
1) pressure exerted by blood against the walls of the arterial system.
2) peak pressure exerted against the arteries when the heart contracts.
3) residual pressure in the arterial system during ventricular relaxation (or filling).
45
The two main factors influencing BP are?
CO and systemic vascular resistance (SVR)
BP = CO x SVR
- SVR is the force opposing the movement of blood. This force is created primarily in small arteries and arterioles. Normal blood pressure is SBP <120 mm Hg and DBP <80 mm Hg
46
BP can be measured by?
1) invasive techniques (catheter inserted in an artery)
| 2) noninvasive techniques (using a sphygmomanometer and a stethoscope, or an automated noninvasive device).
47
Noninvasive, indirect measurement of BP can be done with a sphygmomanometer and stethoscope. The sphygmomanometer consists of an inflatable cuff and a pressure gauge. The BP is measured by auscultating for sounds of turbulent blood flow through a compressed artery, termed?
- What is the recommended site for taking a BP?
Korotkoff sounds
| - The brachial artery is the recommended site for taking a BP.
48
```
Blood pressure:
Systolic blood pressure (SBP)
-
Diastolic blood pressure (DBP)
-
BP =
```
```
- Systolic blood pressure (SBP)
< 120 mm Hg
- Diastolic blood pressure (DBP)
< 80 mm Hg
- BP = CO x SVR
```
49
A mean arterial pressure (MAP) >___ mm Hg is necessary to sustain the vital organs of an average person under most conditions.
>60 mm Hg
50
Pulse pressure is the?
difference between the SBP and DBP
- normally about one third of the SBP. If BP is 120/80 mm Hg, the pulse pressure is 40 mm Hg.
- increased pulse pressure due to an increased SBP may occur during exercise or in individuals with atherosclerosis of the larger arteries.
- A decreased pulse pressure may be found in heart failure or hypovolemia.
51
Another measurement related to BP is mean arterial pressure (MAP). The MAP refers to the?
average pressure within the arterial system that is felt by organs in the body. It is not the average of the DBP and SBP, because the length of diastole exceeds that of systole at normal HRs. MAP is calculated as follows:
MAP = (SBP + 2DBP)/3
52
Mean arterial pressure: A person with a BP of 120/60 mm Hg has an estimated MAP of 80 mm Hg. In patients with invasive BP monitoring, this value is automatically calculated and takes the patient's HR into consideration. A MAP greater than 60 mm Hg is needed to?
- When the MAP falls below this number for a period of time, what happens?
- MAP greater than 60 mm Hg is needed to adequately perfuse and sustain the vital organs of an average person under most conditions.
- vital organs are underperfused and will become ischemic.
53
MAP Range
60-100 mm Hg
54
- Risk for cardiovascular disease (CVD) increases with?
- CVD leading cause of death in adults \
- Cardiovascular changes result of?
- age
- > 65 years of age
- aging, disease, environmental factors, and lifetime behaviors
55
Gerontologic Considerations: Effects of Aging on the Cardiovascular System
- With increased age, the amount of collagen in the heart increases and elastin decreases.
1) These changes affect the?
2) One of the major changes in the cardiovascular system is the response to physical or emotional stress. In times of increased stress, what happens?
3) The resting supine HR is not markedly affected by aging. When the patient changes positions (e.g., sits upright), the?
1) heart muscle's ability to stretch and contract.
2) CO and SV decrease due to reduced contractility and HR response.
3) sympathetic nerve pathway may be affected by fibrous tissue and fatty deposits, resulting in a blunted (reduced) HR response
56
Age related changes
- Increased collagen, decreased elastin
- Decreased response to stress
- Heart valves become thick and stiff.
- Number of pacemaker cells decrease.
- Decreased number and function of β-adrenergic receptors
- Blood vessels thicken and less elastic
- Increase in SBP and decrease or no change in DBP
- Incompetent venous valves
- Orthostatic hypotension
- Postprandial hypotension
57
Gerontologic Considerations: Effects of Aging on the Cardiovascular System
- Heart valves become thicker and stiffer from lipid accumulation, degeneration of collagen, and fibrosis. The aortic and mitral valves are most frequently affected. These changes result in either?
regurgitation of blood when the valve should be closed or narrowing of the orifice of the valve (stenosis) when the valve should be open. The turbulent blood flow across the affected valve results in a murmur.
58
Gerontologic Considerations: Effects of Aging on the Cardiovascular System
- The number of pacemaker cells in the SA node decreases with age.
1) By age 75, a person may have only 10% of the normal number of pacemaker cells. Although this is compatible with adequate SA node function, it may account for the frequency of some sinus dysrhythmias in older adults. Similar decreases 663also occur in the number of conduction cells in the internodal tracts, bundle of His, and bundle branches. These changes contribute to the development of atrial dysrhythmias and heart blocks. About 50% of older adults have an abnormal resting ECG that shows increases in the PR, QRS, and/or QT intervals
The number of pacemaker cells in the SA node decreases with age. By age 75, a person may have only 10% of the normal number of pacemaker cells. Although this is compatible with adequate SA node function, it may account for the frequency of some sinus dysrhythmias in older adults. Similar decreases 663also occur in the number of conduction cells in the internodal tracts, bundle of His, and bundle branches. These changes contribute to the development of atrial dysrhythmias and heart blocks. About 50% of older adults have an abnormal resting ECG that shows increases in the PR, QRS, and/or QT intervals
59
Gerontologic Considerations: Effects of Aging on the Cardiovascular System
- The number of pacemaker cells in the SA node decreases with age.
1) By age 75, a person may have only?
2) Similar decreases also occur in the number of conduction cells in the?
3) About 50% of older adults have an abnormal resting ECG that shows?
1) 10% of the normal number of pacemaker cells.
| 2) internodal tracts, bundle of His, and bundle branches. 3) increases in the PR, QRS, and/or QT intervals
60
Gerontologic Considerations: Effects of Aging on the Cardiovascular System
The autonomic nervous system control of the cardiovascular system changes with aging. The number and function of β-adrenergic receptors in the heart decrease with age. So the older adult not only has a decreased response to physical and emotional stress but also is less sensitive to β-adrenergic agonist drugs. The lower maximum HR during exercise results in?
only a twofold increase in CO compared with the three or four times increase seen in younger adults.
61
Gerontologic Considerations: Effects of Aging on the Cardiovascular System
- Arterial and venous blood vessels thicken and become less elastic with age. Arteries increase their sensitivity to vasopressin (antidiuretic hormone). With aging both of these changes contribute to a?
- Valves in the large veins in the lower extremities have a reduced ability to?
- progressive increase in SBP and a decrease or no change in DBP. Thus an increase in the pulse pressure is found.
- return the blood to the heart, often resulting in dependent edema.
62
Gerontologic Considerations: Effects of Aging on the Cardiovascular System
- Orthostatic hypotension, which is estimated to be present in more than 30% of patients over age 70 with?
- Postprandial hypotension (decrease in BP of at least 20 mm Hg that occurs within 75 minutes after eating) may also occur in about?
- Both orthostatic and postprandial hypotension may be related to?
- systolic hypertension, may be related to drugs and/or decreased baroreceptor function.
- a third of otherwise healthy older adults.
- falls in older adults. Despite the changes associated with aging, the heart is able to function adequately under most circumstances.
63
Subjective Data: Health information
1) History of present illness
2) Past health history
3) Past and current medications
4) Surgery or other treatments
64
Subjective Data: Functional health patterns
1) Health perception-health management pattern
2) Nutritional-metabolic pattern
3) Elimination pattern
4) Activity-exercise pattern
65
Past Health History.
| Many illnesses affect the cardiovascular system directly or indirectly. Ask the patient about a history of?
chest pain, SOB, fatigue, alcohol and tobacco use, anemia, rheumatic fever, streptococcal throat infections, congenital heart disease, stroke, palpitations, dizziness with position changes, syncope, hypertension, thrombophlebitis, intermittent claudication, edema, and varicosities.
66
Genetic Risk Alert
1) Coronary Artery Disease
2) Cardiomyopathy
3) Hypertension
1) Coronary Artery Disease
• Specific genetic links, especially related to lipoprotein genes, have been identified for some families with CAD.
• The clustering of CAD in families is strong if there is early age of onset affecting several relatives.
2) Cardiomyopathy
• Hypertrophic cardiomyopathy can be caused by autosomal dominant mutations.
• Dilated cardiomyopathy can be caused by autosomal and X-linked dominant mutations.
3) Hypertension
• Hypertension results from a complex interplay between genetic and environmental factors.
• Lifestyle choices (e.g., smoking, lack of exercise) may trigger genetic tendencies to hypertension.
67
Sleep-Rest Pattern.
Cardiovascular problems often disrupt sleep. Paroxysmal nocturnal dyspnea (attacks of shortness of breath, especially at night that awaken the patient) and Cheyne-Stokes respiration (periods of very shallow breaths to alternating periods of apnea and deep, rapid breathing) are associated with heart failure.
- Many patients with heart failure need to sleep with?
- Sleep apnea has been associated with an increased risk of?
- Nocturia, a common finding with?
- several pillows or upright in a chair. Note the number of pillows needed to sleep or the need to sleep upright (orthopnea) and whether this has changed recently.
- life-threatening dysrhythmias, especially in patients with heart failure
- cardiovascular patients, also interrupts normal sleep patterns. Fully explore both conditions.
68
Sexuality-Reproductive Pattern.
Ask the patient about the effect of the cardiovascular problem on sexual activity. Because some patients often fear sudden death during sexual intercourse, it may lead to changes in their sexual behavior. Fatigue, chest pain, or shortness of breath may also limit sexual activity.
- Erectile dysfunction (ED) may be a symptom of?
peripheral vascular disease and/or a side effect of some drugs used to treat CVD (e.g., β-blockers, diuretics). Ask about the use of drugs for ED (e.g., sildenafil [Viagra]). These drugs are contraindicated if the patient is also taking a nitrate because the combination can cause significant hypotension.8 Decide if counseling may be helpful.
69
Subjective Data: Functional health patterns
1) Sleep-rest pattern
2) Cognitive-perceptual pattern
3) Self-perception-self-concept pattern
4) Role-relationship pattern
5) Sexuality-reproductive pattern
6) Coping-stress tolerance pattern
7) Values-belief pattern
70
Objective Data: Physical examination
- Vital signs
- Peripheral vascular system
* Inspection
* Palpation
* Auscultation
71
Objective Data: Physical Examination
Vital Signs.
After you observe the patient's general appearance, obtain vital signs.
- Measure BP bilaterally. These readings can vary from 5 to 15 mm Hg.
- Use the arm with the highest BP for subsequent measurements.
- Take orthostatic (postural) BPs and HRs while the patient is supine, sitting with legs dangling, and standing. SBP should not decrease more than 20 mm Hg from the supine to the standing position. HR should not increase more than 20 beats/minute from the supine to the standing position.
72
Peripheral Vascular System
Inspection.
Inspect the skin for color, hair distribution, and venous pattern. Check the extremities for conditions such as?
- edema, dependent rubor, clubbing of the nail beds, varicosities, and lesions such as stasis ulcers. Edema in the legs can be caused by gravity, varicosities, or right-sided heart failure.
73
Peripheral vascular system
Inspect the large veins in the neck (internal and external jugular) while the patient is gradually moved from a supine position to an upright (30 to 45 degrees) position. Distention and prominent pulsations of these neck veins, referred to as?
jugular venous distention, can be caused by right-sided heart failure.
74
Palpation.
Palpate the upper and lower extremities for temperature, moisture, pulses, and edema bilaterally to assess for symmetry. Look for edema by depressing the skin over the tibia or medial malleolus for 5 seconds. Normally, there is no depression after releasing pressure. If pitting edema is present, grade it from?
1+ (mild pitting, slight brief indentation) to 4+ (very deep pitting, indentation that lasts a long time)
75
Palpate the pulses in the neck and extremities for information on arterial blood flow. Assess the rhythm (e.g., regular, irregular) and force. It is important to palpate each carotid pulse separately to avoid vagal stimulation and possible dysrhythmias. Compare the characteristics of the arteries on the?
right and left extremities simultaneously to determine symmetry.
76
When palpating the arteries, rate the force of the pulse using the following scale:
```
0 = Absent
1+ = Weak
2+ = Normal
3+ = Increased, full, bounding
```
77
Palpating pulses: The rigidity (hardness) of the vessel should also be noted. The normal pulse feels like a tap, whereas a vessel wall that is narrowed or bulging does what?
vibrates. The term for a palpable vibration is thrill.
78
Capillary refill is used to assess? How is it done?
arterial flow to the extremities.
- Position the patient's hands near the level of the heart and squeeze a nail bed to produce blanching. Observe for the return of color. This should occur in less than 2 seconds with normal tissue perfusion and CO.
79
Auscultation.
An artery that is narrowed or has a bulging wall may create turbulent blood flow. This abnormal flow can cause a buzzing or humming termed a bruit.
- This is heard with?
- Auscultation of major arteries such as the?
- the bell of the stethoscope placed over the vessel.
| - carotid arteries, abdominal aorta, and femoral arteries should be part of the initial cardiovascular assessment
80
Jugular venous distention
Description
Possible Etiology
- Description: Distended neck (jugular) veins with patient sitting at 30- to 45-degree angle
- Possible Etiology: Elevated right atrial pressure, right-sided heart failure
81
Central cyanosis
Description
Possible Etiology
- Description: Bluish or purplish tinge in central areas such as tongue, conjunctivae, inner surface of lips
- Possible etiology: Inadequate O2 saturation of arterial blood because of pulmonary or cardiac disorders (e.g., congenital defects)
82
Peripheral cyanosis
Description
Possible Etiology
- Description: Bluish or purplish tinge in extremities or in nose and ears
- Possible etiology: Reduced blood flow because of heart failure, vasoconstriction, cold environment
83
Splinter hemorrhages
Description
Possible Etiology
- Description: Small red to black streaks under fingernails - Possible etiology: Infective endocarditis (infection of endocardium, usually in area of cardiac valves)
84
Clubbing of nail beds
Description
Possible Etiology
- Description: Obliteration of normal angle between base of nail and skin
- Possible Etiology: Endocarditis, congenital defects, prolonged O2 deficiency
85
Color changes in extremities with postural change
- Description
- Possible Etiology
- Description: Pallor, cyanosis, mottling of skin after limb elevation. Dependent rubor (reddish blue discoloration). Glossy skin
- Possible etiology: Chronic decreased arterial perfusion
86
Ulcers Venous:
- Description
- Possible Etiology
- Description: Venous: Necrotic crater-like lesion usually found on lower leg at medial malleolus. Characterized by slow wound healing
- Possible etiology: Poor venous return, varicose veins, incompetent venous valves.
87
Arterial Ulcers
- Description
- Possible Etiology
- Description: Pale ischemic base, well-defined edges usually found on toes, heels, lateral malleoli
- Possible etiology: Arteriosclerosis, diabetes
88
Varicose veins
- Description
- Possible Etiology
- Description: Visible dilated, discolored, tortuous vessels in lower extremities
- Possible Etiology: Incompetent valves in vein
89
Pulse Bounding
- Description
- Possible Etiology
- Description: Sharp, brisk, pounding pulse
| - Possible Etiology: Hyperkinetic states (e.g., anxiety, fever), anemia, hyperthyroidism
90
Thready Pulse
- Description
- Possible Etiology
- Description: Weak, slowly rising pulse easily obliterated by pressure
- Possible Etiology: Blood loss, decreased cardiac output, aortic valve disease, peripheral arterial disease
91
Irregular Pulse
- Description
- Possible Etiology
- Description: Regularly irregular or irregularly irregular. Skipped beats
- Possible Etiolgoy: Cardiac dysrhythmias
92
Pulsus alternans
- Description
- Possible Etiology
- Description: Regular rhythm, but strength of pulse varies with each beat
- Possible Etiology: Heart failure, cardiac tamponade
93
Absent pulse
- Description
- Possible Etiology
- Description: Lack of pulse
| - Possible etiology: Atherosclerosis, trauma, embolus
94
Thrill
- Description
- Possible Etiology
- Description: Vibration of vessel or chest wall
| - Possible etiology: Aneurysm, aortic regurgitation, arteriovenous fistula
95
Rigidity
- Description
- Possible etiology
- Description: Stiffness or inflexibility of vessel wall
| - Possible etiology: Atherosclerosis
96
>100 beats/min
- Description
- Possible etiology
- Description: Tachycardia
| - Possible Etiology: Exercise, anxiety, shock, need for increased cardiac output, hyperthyroidism
97
<60 beats/min
- Description
- Possible etiology
- Description: Bradycardia
- Possible etiology: Rest or sleeping, SA or AV node damage, athletic conditioning, side effect of drugs (e.g., β-blockers), hypothyroidism
98
Cold extremities
- Description
- Possible etiology
- Description: Hands and/or feet cold to touch. External covering necessary for comfort
- Possible etiology: Intermittent claudication, peripheral arterial disease, low cardiac output, severe anemia
99
Objective data: Vital signs
- Measure BP bilaterally. readings can vary from 5- 15 mm Hg.
- Use arm with highest BP for subsequent measurements. - Take orthostatic (postural) BPs and HRs while patient is supine, sitting with legs dangling, and standing. SBP should not decrease more than 20 mm Hg from the supine to the standing position. HR should not increase more than 20 beats/minute from the supine to the standing position.
100
Objective data: Inspection.
Inspect the skin for color, hair distribution, and venous pattern. Check the extremities for conditions such as edema, dependent rubor, clubbing of the nail beds, varicosities, and lesions such as stasis ulcers. Edema in the legs can be caused by gravity, varicosities, or right-sided heart failure.
- Inspect the large veins in the neck (internal and external jugular) while the patient is gradually moved from a supine position to an upright (30 to 45 degrees) position. Distention and prominent pulsations of these neck veins, referred to as jugular venous distention, can be caused by?
right-sided heart failure.
101
Objective data: Palpation.
Palpate the upper and lower extremities for temperature, moisture, pulses, and edema bilaterally to assess for symmetry. Look for edema by depressing the skin over the?
tibia or medial malleolus for 5 seconds. Normally, there is no depression after releasing pressure. If pitting edema is present, grade it from 1+ (mild pitting, slight brief indentation) to 4+ (very deep pitting, indentation that lasts a long time)
102
When palpating the arteries, rate the force of the pulse using the following scale:
```
0 = Absent
1+ = Weak
2+ = Normal
3+ = Increased, full, bounding
```
103
Objective data: The rigidity (hardness) of the vessel should also be noted. The normal pulse feels like a?
tap, whereas a vessel wall that is narrowed or bulging vibrates. The term for a palpable vibration is thrill.
104
Objective data: Capillary refill is used to assess arterial flow to the extremities. Position the patient's hands near the level of the heart and squeeze a nail bed to produce blanching. Observe for the return of color. This should occur in?
less than 2 seconds with normal tissue perfusion and CO.
105
Objective data: Auscultation.
An artery that is narrowed or has a bulging wall may create turbulent blood flow. This abnormal flow can cause a buzzing or humming termed a bruit. This is heard with the bell of the stethoscope placed over the vessel. Auscultation of major arteries such as the?
carotid arteries, abdominal aorta, and femoral arteries should be part of the initial cardiovascular assessment.
106
Common sites for palpating arteries
- Carotid (neck)
- Brachial (inside elbow)
- Radial
- Ulnar
- Femoral
- Popliteal (behind knee)
- Posterior tibial (medial ankle)
- Dorsalis pedis (top of foot)
107
Assessment of cardiovascular system anatomic landmarks
1) Aortic area (base of heart)
2) Pulmonic area
3) Erb's point
4) Tricuspid area
5) Mitral area (apex of heart) and PMI
108
Objective data: Auscultation.
Normal heart sounds are made by the movement of blood through the heart valves. These sounds can be heard through a stethoscope placed on the chest wall.
1) The first heart sound (S1) is associated with?
2) The second heart sound (S2) is associated with closure of the aortic and pulmonic valves. It has a sharp dupp sound.
3) S1 and S2 signals?
1) closure of the tricuspid and mitral valves. It has a soft lubb sound.
2) closure of the aortic and pulmonic valves. It has a sharp dupp sound.
3) S1 signals the beginning of systole. S2 signals the beginning of diastole
109
S1 and S2 are heard best with the diaphragm of the stethoscope because they are high pitched. Extra heart sounds (S3 or S4), if present, are heard best with the bell of the stethoscope because they are low pitched.
1) Have the patient do what to enhance the sounds from the second ICSs (aortic and pulmonic areas)?
2) Place the patient in what position to enhance the sounds at the mitral area?
1) Have the patient lean forward while sitting to enhance the sounds from the second ICSs (aortic and pulmonic areas).
2) Place the patient in a left side-lying position to enhance the sounds at the mitral area.
110
When auscultating the apical area, simultaneously palpate the radial pulse. Determine whether the rhythm is regular or irregular while listening and feeling. If the apical and radial pulses are not equivalent, count the apical pulse while a second person simultaneously counts the radial pulse for 1 full minute. The difference between the two numbers is called a?
pulse deficit and can indicate dysrhythmias.
111
Normally no sound is heard between S1 and S2. Sounds heard during these periods may represent abnormalities and should be described. An exception to this is a normal splitting of S2, which is best heard at the?
pulmonic area during inspiration. Splitting of this heart sound can be abnormal if it is heard during expiration or if it is constant (fixed) during the respiratory cycle.
112
Heart sounds
1) The S3 heart sound is a low-intensity vibration of the ventricular walls usually associated with decreased compliance of the ventricles during filling. An S3 heart sound may be normal (physiologic) in young adults. It is pathologic in patients with?
2) The S4 heart sound is a low-frequency vibration caused by atrial contraction. It precedes S1 of the next cycle, and is known as an atrial gallop. An S4 heart sound may be normal in older adults with no evidence of heart disease. It is pathologic in patients with?
1) left-sided heart failure or mitral valve regurgitation. S3 is heard closely after S2 and is known as a ventricular gallop.
2) CAD, cardiomyopathy, left ventricular hypertrophy, or aortic stenosis.
113
Pericardial friction rubs are sounds caused by friction that occurs when inflamed surfaces of the pericardium (pericarditis) move against each other. They are?
high-pitched, scratchy sounds that may be intermittent and may last several hours to days. Friction rubs are heard best at the apex, with patients upright and leaning forward, and while holding their breath following expiration
114
When cells are injured, they release their contents, including enzymes and other proteins, into the circulation. These biomarkers are useful in the diagnosis of acute coronary syndrome (ACS).
- What are the cardiac biomarkers?
1) Troponin
2) Creatine kinase (CK)
3) Myoglobin
115
Rises within 4-6 hours, peaks 10-24 hours, detected for up to 10-14 days
Troponin
116
Rises in 3-6 hours, peaks in 12-24 hours, returns to baseline within 12-48 hours
Creatine kinase (CK)
117
Cardiac biomarkers: Cardiac-specific troponin is a heart muscle protein released into circulation after injury or infarction.
1) Two subtypes:
2) Normally the level in the blood is very low, so a rise in level is diagnostic of myocardial infarction (MI) or injury. cTnT and cTnI are detectable within?
3) Troponin is the biomarker of choice in the diagnosis o?
4) High-sensitivity troponin (hs-cTnT, hs-cTnI) assays may provide?
1) cardiac-specific troponin T (cTnT) and cardiac-specific troponin I (cTnI), are specific to heart muscle.
2) hours (on average 4 to 6 hours) of MI or injury, peak at 10 to 24 hours, and can be detected for up to 10 to 14 days.
3) diagnosis of ACS.
4) even earlier detection of a heart event
118
Cardiac biomarkers: Creatine kinase (CK) enzymes are found in a variety of organs and tissues and occur as three isoenzymes.
1) These isoenzymes are specific to?
2) CK-MB rise is specific for?
1) skeletal muscle (CK-MM), brain and nervous tissue (CK-BB), and the heart (CK-MB).
2) MI or injury. Levels begin to increase 3 to 6 hours after symptom onset, peak in 12 to 24 hours, and return to baseline within 12 to 48 hours after MI. The peak level and return to normal can be delayed in a patient with a large MI. Levels drop more rapidly in patients who are quickly and successfully treated for an MI.
119
Cardiac biomarkers: Myoglobin is a low-molecular-weight heme protein found in heart and skeletal muscle. Myoglobin elevation is a sensitive?
indicator of very early myocardial injury but lacks specificity for MI. Its usefulness in diagnosing MI is limited
120
Additional blood studies for cardiovascular system:
C-reactive protein (CRP) is a protein produced by the liver during periods of acute inflammation.
1) CRP can be measured using a?
2) An increased level of CRP has been linked with the presence of?
1) high-sensitivity test (hs-CRP).
2) Atherosclerosis and the first occurrence of a heart event. In addition, the level of CRP may predict the risk for future heart events in patients with MI. However, studies on the usefulness of assessing CRP have produced conflicting results, and measuring CRP routinely in patients with and without CVD is not done
121
C-Reactive protein two main points
1) Marker for inflammation
| 2) Risk factor for coronary artery disease (CAD)
122
Elevated levels increased risk for CAD, peripheral vascular disease (PVD), and stroke
Homocysteine
123
Blood studies: Homocysteine (Hcy) is an amino acid that is produced during protein catabolism.
1) Elevated Hcy levels can be?
2) Elevated levels of Hcy have been linked to a higher risk of?
3) It is recommended that Hcy testing be done in patients with a?
1) either hereditary or acquired from dietary deficiencies of vitamin B6, vitamin B12, or folate.
2) CVD, peripheral vascular disease, and stroke.
3) familial predisposition for early CVD or a history of CVD in the absence of other common risk factors
124
Blood studies: Cardiac Natriuretic Peptide Markers.
1) There are three natriuretic peptides:
2) BNP is the marker of choice for distinguishing a?
3) N-terminal pro-brain natriuretic peptide (NT-pro-BNP) is also secreted in the ventricles and is?
4) When DBP increases (e.g., heart failure), BNP and NT-pro-BNP are?
1) (1) atrial natriuretic peptide (ANP) from the atrium, (2) b-type natriuretic peptide (BNP) from the ventricles, and (3) c-type natriuretic peptide from endothelial and renal epithelial cells.
2) cardiac or respiratory cause of dyspnea.
3) more sensitive but less specific than BNP as a diagnostic marker of heart failure
4) released and increase natriuresis (excretion of sodium in the urine)
125
Cardiac natriuretic peptide markers main points
- Three types
1) Atrial natriuretic peptide (ANP)
2) B-type natriuretic peptide (BNP)
3) C-type natriuretic peptide
- Increased levels of BNP levels signify heart failure.
- NT-pro-BNP
126
Diagnostic Studies of Cardiovascular System
- Serum Lipids
- Lipoprotein
- Serum Lipids
* Triglycerides
* Cholesterol
* Phospholipids
- Lipoprotein
* Lipids must bind to protein to circulate in blood
127
Serum lipids consist of?
triglycerides, cholesterol, and phospholipids. They circulate in the blood bound to protein. Thus they are often referred to as lipoproteins.
128
Serum lipids:
1) Triglycerides are the?
2) Cholesterol, a structural component of cell membranes and plasma lipoproteins, is a precursor of?
3) Phospholipids contain?
4) Apoproteins are water-soluble proteins that?
1) main storage form of lipids and make up about 95% of fatty tissue.
2) corticosteroids, sex hormones, and bile salts. In addition to being absorbed from food in the gastrointestinal tract, cholesterol can also be synthesized in the liver.
3) glycerol, fatty acids, phosphates, and a nitrogenous compound. Although formed in most cells, phospholipids usually enter the circulation as lipoproteins synthesized by the liver.
4) combine with most lipids to form lipoproteins.
129
Different classes of lipoproteins contain varying amounts of the naturally occurring lipids. These include the following:
1. Chylomicrons: primarily exogenous triglycerides from dietary fat
2. Low-density lipoproteins (LDLs): mostly cholesterol with moderate amounts of phospholipids
3. High-density lipoproteins (HDLs): about 50% protein and 50% phospholipids and cholesterol
4. Very-low-density lipoproteins (VLDLs): primarily endogenous triglycerides with moderate amounts of phospholipids and cholesterol
130
Serum lipids: A lipid panel usually measures cholesterol, triglyceride, LDL, and HDL.
1) Elevations in triglycerides and LDL are strongly associated with?
2) An increased HDL level is associated with?
3) High levels of HDLs serve a?
1) CAD
2) A decreased risk of CAD
3) protective role by mobilizing cholesterol from tissues
131
Serum lipids: Although an association exists between elevated serum cholesterol levels and CAD, a measure of total cholesterol alone is not sufficient for an assessment of CAD. A risk assessment is calculated by comparing the?
total cholesterol to HDL ratio over time. An increase in the ratio indicates increased risk. This provides more information than either value alone.
132
Serum lipids: Plasma levels of apolipoprotein A-I (apo A-I) (the major HDL protein) and the ratio of apo A-I to apolipoprotein B (apo B) (the major LDL protein) are stronger predictors of CAD than?
the HDL cholesterol level alone. Measurements of these lipoproteins can be useful in identifying patients at risk for CAD
133
Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an inflammatory enzyme expressed in?
atherosclerotic plaques. Elevated levels of Lp-PLA2 are related to an increased risk of CAD, especially in African American women
134
A patient arrives at an urgent care center after experiencing unrelenting substernal and epigastric pain and pressure for about 12 hours. The nurse reviews laboratory results with the understanding that at this point in time, a myocardial infarction would by indicated by peak levels of
a. Troponin T.
b. Homocysteine.
c. Creatine kinase-MB.
d. Type b natriuretic peptide.
Troponin T.
Rationale: Troponin is the biomarker of choice in the diagnosis of myocardial infarction. Troponin is a myocardial muscle protein released into the circulation after injury. Troponin levels peak at 10 to 24 hours.
135
Chest X-Ray
A radiographic picture of the chest can show heart shape and size, and anatomic changes in individual chambers. The chest x-ray records any?
displacement or enlargement of the heart, extra fluid around the heart (pericardial effusion), and pulmonary congestion.
136
Echocardiogram main points
- Ultrasound of heart
- With or without contrast
- Provides information regarding structures and motion of heart
- Measures ejection fraction
- Stress echocardiography
- Transesophageal echo (TEE)
137
The echocardiogram uses ultrasound (US) waves to record the movement of the structures of the heart. In the normal heart, US waves directed at the heart are reflected back in typical patterns.
- Contrast echocardiography involves the?
addition of an IV contrast agent (e.g., agitated saline) to assist in defining the images, especially in technically difficult patients (e.g., obese).
138
Echocardiogram: The echocardiogram provides information about abnormalities of?
(1) valvular structures and motion
(2) heart chamber size and contents
(3) ventricular and septal motion and thickness
(4) pericardial sac
(5) ascending aorta.
- The ejection fraction (EF), or the percentage of end-diastolic blood volume that is ejected during systole, can also be measured. The EF provides information about the function of the left ventricle during systole.
139
Two commonly used types of echocardiograms are the?
1) motion-mode (M-mode) echocardiogram
2) two-dimensional (2-D) echocardiogram.
- In the M-mode, a single US beam is directed toward the heart, recording the motion of the intracardiac structures and detecting wall thickness and chamber size.
- The 2-D echocardiogram sweeps the US beam through an arc, producing a cross-sectional view. This shows correct spatial relationships among the structures.
140
Diagnostic Studies of Cardiovascular System: Cardiac catheterization
- Right-sided to measure pressures
| - Left-sided to evaluate coronary arteries
141
Diagnostic Studies of Cardiovascular System: Coronary angiography
Uses contrast medium to identify coronary blockages
142
A patient returns to the cardiac observation area following a cardiac catheterization with coronary angiography. Which of the following assessments would require immediate action by the nurse?
1. Pedal pulses are 2+ bilaterally.
2. Apical pulse is 54 beats/minute.
3. Mean arterial pressure is 72 mm Hg.
4. ST-segment elevation develops on the ECG.
ST-segment elevation develops on the ECG.
Rational: ST elevation on ECG indicates myocardial ischemia or injury with partial or total occlusion of a coronary artery. This assessment finding requires immediate action. Actions would include assessment for chest pain, 12-lead ECG, administration of nitroglycerin or morphine, and notification of the health care provider. Option 1 would need further assessment but is not critical unless the patient is symptomatic (chest pain, shortness of breath, hypotension, etc.). Options 2 and 3 are normal findings.
143
Cardiac catheterization is a common procedure. It provides information about CAD, coronary spasm, congenital and valvular heart disease, and ventricular function. Cardiac catheterization is also used to measure intracardiac pressures and O2 levels, as well as CO and EF. With injection of?
contrast media and fluoroscopy, the coronary arteries can be seen, chambers of the heart can be outlined, and wall motion can be observed.
144
Cardiac catheterization is done by inserting a radiopaque catheter into the right and/or left side of the heart.
1) For the right side of the heart, a catheter is inserted through an?
2) Pressures are recorded as the catheter is moved into the vena cava, right atrium, right ventricle, and pulmonary artery. The catheter is then moved until it is wedged or lodged in position. This blocks the blood flow and pressure from the?
1) arm vein (basilic or cephalic) or a leg vein (femoral).
2) right side of the heart and looks ahead through the pulmonary capillary bed to the pressure in the left side of the heart (pulmonary artery wedge pressure). This pressure is used to assess the function of the left side of the heart.
145
Left-sided heart catheterization is done by inserting a catheter into a?
radial, femoral, or brachial artery. The catheter is passed in a retrograde manner up to the aorta, across the aortic valve, and into the left ventricle.
146
Coronary angiography is done with a left-sided heart catheterization.
1) The catheter is positioned at the?
2) Patients often feel a temporary flushed sensation with dye injection. The images identify the?
3) Complications of cardiac catheterization include?
1) origin of the coronary arteries, and contrast medium is injected into the arteries.
2) location and severity of any coronary blockages
3) bleeding or hematoma at the puncture site; allergic reactions to the contrast media; looping or kinking of the catheter; infection; thrombus formation; aortic dissection; dysrhythmias; MI; stroke; and puncture of the ventricles, septum, or lung tissue.
147
Troponin (cardiac)
| Description and purpose
- Contractile proteins that are released after an MI. Both troponin T and troponin I are highly specific to cardiac tissue.
- Reference intervals:
* Troponin I (cTnI)
Negative: <0.5 ng/mL (<0.5 mcg/L)
Indeterminate or suspicious for injury to myocardium: 0.5-2.3 ng/mL (0.5-2.3 mcg/L)
- Positive for myocardial injury: >2.3 ng/mL (>2.3 mcg/L)
Troponin T (cTnT)
<0.1 ng/mL (<0.1 mcg/L)
148
Troponin (cardiac)
| Nursing Responsibility
- Before: Explain purpose of serial sampling (e.g., q6hr × 3) in conjunction with CK-MB and serial ECGs.
- During: Rapid point-of-care (bedside) assays are available.
149
Blood studies: CK-MB
| Description and purpose
Cardiospecific isoenzyme that is released from cells when myocardial tissue is injured. Concentrations >4%-6% of total creatine kinase (CK) are highly indicative of MI. Serum levels increase within 4-6 hr after MI.
150
Blood studies: CK-MB
| Nursing Responsibility
Before: Explain purpose of serial sampling that is often done in conjunction with troponin and ECGs
151
Blood studies: Myogloblin
| Description and purpose
- Serum concentrations rise 30-60 min after MI and raidly cleared from circulation. Limited use in the diagnosis of cardiac injury/infarction.
- Reference interval:
* Male: 15.2-91.2 mcg/L
* Female: 11.1-57.5 mcg/L
152
Blood studies: Myogloblin
| Nursing responsiblity
Before: Explain to patient that blood is drawn and sent to laboratory.
153
Blood studies: C-reactive protein (CRP)
| Description and purpose
- Marker of inflammation. May have value in predicting risk of cardiac disease and cardiac events. High-sensitivity (hs) CRP assay used.
- Lowest risk: <1 mg/L
- Moderate risk: 1-3 mg/L
- High risk: >3 mg/L
154
Blood studies: C-reactive protein (CRP)
| Nursing responsiblity
Before: Explain to patient that blood is drawn and sent to laboratory.
155
Blood studies: Homocysteine
| Description and purpose
- Amino acid produced during protein catabolism that has been identified as a risk factor for cardiovascular disease. Homocysteine may cause damage to the endothelium or have a role in formation of thrombi.
- Reference interval:
* Male: 5.2-12.9 µmol/L
* Female: 3.7-10.4 µmol/L
156
Blood studies: b-Type natriuretic peptide (BNP)
| Description and purpose
- Peptide that causes natriuresis. Elevation helps to distinguish cardiac vs. respiratory cause of dyspnea. Infusion of nesiritide (Natrecor) elevates levels temporarily.
- Reference interval:
BNP (diagnostic for heart failure) >100 pg/mL (28.8 pmol/L)
157
Blood studies: NT-Pro-BNP
| Description and purpose
- Aids in assessing the severity of heart failure in symptomatic and asymptomatic patients. In patients with renal insufficiency, concentrations may increase and may not correlate with New York Heart Association functional classification of heart failure.
Reference interval:
≤74 yr: 124 pg/mL
>75 yr: 449 pg/mL
158
Serum lipids: Triglycerides
| Description and purpose
- Mixtures of fatty acids. Elevations are associated with cardiovascular disease and diabetes.
- Reference interval:
<150 mg/dL (<1.7 mmol/L) (varies with age)
159
Serum lipids: Triglycerides
| Nursing responsiblity
- Before: Explain to patient that blood is drawn and sent to laboratory. Alcohol should be withheld for 24 hr before testing.
- During: Can be obtained in a nonfasting state. Some protocols continue to recommend obtaining results in a fasting state.
160
A patient with a tricuspid valve disorder will have impaired blood flow between the
a. vena cava and right atrium.
b. left atrium and left ventricle.
c. right atrium and right ventricle.
d. right ventricle and pulmonary artery.
c. right atrium and right ventricle.
161
A patient has a severe blockage in his right coronary artery. Which heart structures are most likely to be affected by this blockage (select all that apply)?
a. AV node
b. Left ventricle
c. Coronary sinus
d. Right ventricle
e. Pulmonic valve
Correct answers: a, b, d
Rationale: The right coronary artery (RCA) supplies blood to the right atrium, the right ventricle, and a portion of the posterior wall of the left ventricle. In 90% of people, the RCA supplies blood to the atrioventricular (AV) node, the bundle of His, and part of the cardiac conduction system.
162
The portion of the vascular system responsible for hemostasis is the
a. thin capillary vessels.
b. endothelial layer of the arteries.
c. elastic middle layer of the veins.
d. smooth muscle of the arterial wall.
b. endothelial layer of the arteries.
Rationale: The innermost lining of the arteries is the endothelium. The endothelium maintains hemostasis, promotes blood flow, and under normal conditions, inhibits blood coagulation.
163
When a person's blood pressure rises, the homeostatic mechanism to compensate for an elevation involves stimulation of
a. baroreceptors that inhibit the sympathetic nervous system, causing vasodilation.
b. chemoreceptors that inhibit the sympathetic nervous system, causing vasodilation.
c. baroreceptors that inhibit the parasympathetic nervous system, causing vasodilation.
d. chemoreceptors that stimulate the sympathetic nervous system, causing an increased heart rate.
Correct answer: a
Rationale: Baroreceptors in the aortic arch and carotid sinus are sensitive to stretch or pressure within the arterial system. Stimulation of these receptors sends information to the vasomotor center in the brainstem. This results in temporary inhibition of the sympathetic nervous system and enhancement of the parasympathetic influence, which cause a decrease in heart rate and peripheral vasodilation.
164
A P wave on an ECG represents an impulse arising at the
a. SA node and repolarizing the atria.
b. SA node and depolarizing the atria.
c. AV node and depolarizing the atria.
d. AV node and spreading to the bundle of His
Correct answer: b
Rationale: The first wave, P, begins with the firing of the sinoatrial (SA) node and represents depolarization of the fibers of the atria
165
When collecting subjective data related to the cardiovascular system, which information should be obtained from the patient (select all that apply)?
a. Annual income
b. Smoking history
c. Religious preference
d. Number of pillows used to sleep
e. Blood for basic laboratory studies
The health history should include assessment of tobacco use. The patient should be asked about any cultural or religious beliefs that may influence the management of the cardiovascular problem. Patients with heart failure may need to sleep with the head elevated on pillows or sleep in a chair.
166
The auscultatory area in the left midclavicular line at the level of the fifth ICS is the best location to hear sounds from which heart valve?
a. Aortic
b. Mitral
c. Tricuspid
d. Pulmonic
Correct answer: b
Rationale: The mitral valve can be assessed by auscultation at the left midclavicular line at the fifth intercostal space (ICS).
167
When assessing a patient, you note a pulse deficit of 23 beats. This finding may be caused by
a. dysrhythmias.
b. heart murmurs.
c. gallop rhythms.
d. pericardial friction rubs
Correct answer: a
Rationale: A pulse deficit occurs if there is a difference between the apical and radial beats per minute. A pulse deficit indicates cardiac dysrhythmias.
168
When assessing the cardiovascular system of a 79-year-old patient, you may expect to find
a. a narrowed pulse pressure.
b. diminished carotid artery pulses.
c. difficulty in isolating the apical pulse.
d. an increased heart rate in response to stress.
c. difficulty in isolating the apical pulse.
Rational: Myocardial hypertrophy and the downward displacement of the heart in an older adult may cause difficulty in isolating the apical pulse.
169
Which nursing responsibilities are priorities when caring for a patient returning from a cardiac catheterization (select all that apply)?
a. Monitoring vital signs and ECG
b. Checking the catheter insertion site and distal pulses
c. Assisting the patient to ambulate to the bathroom to void
d. Informing the patient that he will be sleepy from the general anesthesia
e. Instructing the patient about the risks of the radioactive isotope injection
Correct answers: a, b
Rationale: The nursing responsibilities after cardiac catheterization include assessment of the puncture site for hematoma and bleeding; assessment of circulation to the extremity used for catheter insertion and of peripheral pulses, color, and sensation of the extremity; and monitoring vital signs and electrocardiographic rhythm. Other nursing responsibilities are described in Table 31-6.
