NCLEX: Cardiovascular disorders

Cardiovascular disorders: A look at cardiovascular disorders

Focus topic: Cardiovascular disorders

Although people are living longer than ever before, they’re increasingly living with chronic conditions or the effects of acute ones. Of these conditions, cardiovascular disorders head the list. In the United States, over 80 million people suffer from some form of cardiovascular disorder, and many of them suffer from a combination of disorders. Year after year, the number of affected patients continues to rise.
Because of this upward trend, you’ll be dealing with cardiovascular patients more often. To provide effective care for these patients, you need a clear understanding of cardiovascular anatomy and physiology, assessment techniques, diagnostic tests, and treatments as well as cardiovascular disorders.

 

Cardiovascular disorders: Anatomy and physiology

Focus topic: Cardiovascular disorders

The cardiovascular system delivers oxygenated blood to tissues and removes waste products. The heart, controlled by the autonomic nervous system, pumps blood to all organs and tissues of the body. Arteries and veins (the vascular system) carry blood throughout the body, keep the heart filled with blood, and maintain blood pressure. Let’s look at each part of this critical system.

Cardiovascular disorders: Heart

Focus topic: Cardiovascular disorders

The heart is a hollow, muscular organ about the size of a closed fist. Located between the lungs in the mediastinum, it’s about 5 (12.5 cm) long and 31/2 (9 cm) in diameter at its widest point. It weighs between 8.8 and 10 oz (250 to 285 g).

Where’s your heart?

Focus topic: Cardiovascular disorders

The heart spans the area from the second to the fifth intercostal space. The right border of the heart lines up with the right border of the sternum. The left border lines up with the left midclavicular line. The exact position of the heart may vary slightly with each patient. Leading into and out of the heart are the great vessels:
• inferior vena cava
• superior vena cava
• aorta
• pulmonary artery
• four pulmonary veins.

Slip and slide

Focus topic: Cardiovascular disorders

A thin sac called the pericardium protects the heart. It has an inner, or visceral, layer that forms the epicardium and an outer, or parietal, layer. The space between the two layers contains 10 to 30 ml of serous (pericardial) fluid which prevents friction between the layers as the heart pumps.

Chamber made

Focus topic: Cardiovascular disorders

The heart has four chambers — two atria and two ventricles —separated by a cardiac septum. The upper atria have thin walls and serve as reservoirs for blood. They also boost the amount of blood moving into the lower ventricles, which fill primarily by gravity.

Blood pathways
Blood moves to and from the heart through specific pathways.
Deoxygenated venous blood returns to the right atrium through three vessels:
superior vena cava — returning blood from the upper body
inferior vena cava — returning blood from the lower body
coronary sinus — returning blood from the heart muscle.

Cardiovascular disorders

Get some fresh air

Focus topic: Cardiovascular disorders

Blood in the right atrium empties into the right ventricle and is then ejected through the pulmonic valve into the pulmonary artery when the ventricle contracts. The blood then travels to the lungs to be oxygenated.

Share the wealth

Focus topic: Cardiovascular disorders

From the lungs, blood travels to the left atrium through the pulmonary veins. The left atrium empties the blood into the left ventricle, which then pumps the blood through the aortic valve into the aorta and throughout the body with each contraction. Because the left ventricle pumps blood against a much higher pressure than the right ventricle, its wall is three times thicker.

Valves
Valves in the heart keep blood flowing in only one direction through the heart. Think of the valves as traffic cops at the entrances to one-way streets, preventing blood from traveling the wrong way despite great pressure to do so. Healthy valves open and close as a result of pressure changes within the four heart chambers.

Matching sets

Focus topic: Cardiovascular disorders

The heart has two sets of valves:
atrioventricular (between atria and ventricles) — tricuspid valve on the heart’s right side and mitral (bicuspid) valve on its left
semilunar — pulmonary valve (between the right ventricle and pulmonary artery) and aortic valve (between the left ventricle and aorta).

On the cusp

Focus topic: Cardiovascular disorders

Each valve has cusps (leaflets), which are anchored to the heart wall by cords of fibrous tissue (chordae tendineae). The cusps of the valves act to maintain tight closure. The tricuspid valve has three cusps, the mitral valve has two cusps, and each of the semilunar valves has three cusps.

Cardiac cycle
Contractions of the heart occur in a rhythm — the cardiac
cycle — and are regulated by impulses that normally begin at the sinoatrial (SA) node, the heart’s pacemaker. The impulses are conducted from there throughout the heart. Impulses from the autonomic nervous system affect the SA node and alter its firing rate to meet the body’s needs. The cardiac cycle consists of two phases: diastole and systole.

Just relax… then, kick!

Focus topic: Cardiovascular disorders

During diastole, the heart relaxes and fills with blood and the heart muscle receives its own supply of blood from the coronary arteries. The mitral and tricuspid valves are open, and the aortic and pulmonic valves are closed. Diastole has three phases:

isovolumetric relaxation — when ventricular pressure drops below the pressure in the aorta and the pulmonary artery, allowing blood to back up toward the ventricles and causing the aortic and pulmonic valves to snap shut, leading to the second heart sound (S2) and atrial filling (the beginning of the cardiac cycle)

ventricular filling (passive) — when 70% of the blood in the atria drains into the ventricles by gravity, which may cause vibrations heard as the third heart sound (S3)

atrial contraction (active), also called atrial kick — when the remaining 30% of blood is pumped into the ventricles, which may cause the fourth heart sound (S4).

Outward bound

Focus topic: Cardiovascular disorders

During systole, ventricular contraction sends blood on its outward journey. Systole has two phases:

isovolumetric contraction — when pressure within the ventricles rises (because of atrial kick) causing the mitral and tricuspid valves to snap closed, which makes the first heart sound (S1)

ventricular ejection — when ventricular pressure rises above the pressure in the aorta and pulmonary artery, causing the aortic and pulmonic valves to open and blood to eject into the pulmonary artery and out to the lungs and into the aorta and out to the rest of the body.

Cardiovascular disorders: Vascular system

Focus topic: Cardiovascular disorders

The vascular system consists of a network of arteries, arterioles, capillaries, venules, and veins. This network is constantly filled with about 5 L of blood. The vascular system delivers oxygen, nutrients, and other substances to the body’s cells and removes the waste products of cellular metabolism.

Cardiovascular disorders

Cardiovascular disorders

Arteries
Arteries carry blood away from the heart. Nearly all arteries carry oxygen-rich blood from the heart throughout the rest of the body. The only exception is the pulmonary artery, which carries oxygen depleted blood from the right ventricle to the lungs.

Tough stuff

Focus topic: Cardiovascular disorders

Arteries have thick walls because they transport blood under high pressure. Arterial walls contain a tough, elastic layer to help propel blood through the arterial system.

Pulse is pressure

Focus topic: Cardiovascular disorders

Arterial pulses are pressure waves of blood generated by the pumping action of the heart. All vessels in the arterial system have pulsations, but you can only feel the pulsations where an artery lies near the skin. You can palpate for these peripheral pulses: temporal, carotid, brachial, radial, ulnar, femoral, popliteal, posterior tibial, and dorsalis pedis. The location of pulse points varies between individuals. Older adults may have diminished peripheral pulses.

Capillaries, arterioles, and venules
The exchange of fluid, nutrients, and metabolic wastes between blood and cells occurs in the capillaries. The exchange can occur because capillaries are thin-walled and highly permeable. At any given moment, the capillaries contain about 5% of the circulating blood volume. They’re connected to arteries and veins through intermediary vessels called arterioles and venules, respectively.

Veins
Veins carry blood toward the heart. Nearly all veins carry oxygen depleted blood, with the sole exception of the pulmonary vein, which carries oxygenated blood from the lungs to the left atrium. Veins serve as a large reservoir for circulating blood.

Feeling flexible

Veins have thinner, more pliable walls than arteries. That pliability allows veins to accommodate variations in blood volume. Veins contain valves at periodic intervals to prevent blood from flowing backward.

Cardiovascular disorders: Assessment

Focus topic: Cardiovascular disorders

Baseline information about cardiovascular status that you gather during assessment will help guide your intervention and follow-up care. Note, however, that if your patient is in a cardiac crisis you’ll have to rethink your assessment priorities. The patient’s condition and the clinical situation will dictate what steps to take.

Cardiovascular disorders: History

Focus topic: Cardiovascular disorders

Begin the assessment with a thorough history. You’ll find that patients with a cardiovascular problem typically cite specific complaints, including:
• chest, neck, arm, or jaw discomfort or pain
• difficulty breathing or shortness of breath
• a “fluttering” feeling in the chest
• cyanosis, pallor, or other skin changes (such as decreased hair distribution and a thin, shiny appearance to the skin)
• high or low blood pressure, weakness, fatigue, or dizziness
• diaphoresis.

Current health status
Ask the following questions to help the patient elaborate on his current illness:
• How long have you had this problem? When did it begin?
• Where’s the pain located? Does the pain radiate to any area of your body? Rate the pain on a scale of 0 to 10.
• Does anything precipitate, exacerbate, or relieve the pain?

Previous health status
Explore all of the patient’s previous major illnesses, recurrent minor illnesses, accidents or injuries, surgical procedures, and allergies.

Historic questions

Focus topic: Cardiovascular disorders

Ask about any history of cardiac-related disorders, such as hypertension, rheumatic fever, scarlet fever, diabetes mellitus, hyperlipidemia, congenital heart defects, and syncope. Ask your patient these questions:
• Have you ever had severe fatigue not caused by exertion?
• Do you consume alcohol, tobacco, or caffeine? How much do you consume?
• Are you taking any prescription, over-the-counter, herbal, or recreational drugs?

• Are you allergic to any drugs, foods, or other products? Can you describe the reaction you experienced? If your patient is female, also ask these questions:
• Have you begun menopause?
• Do you use hormonal contraceptives or estrogen?
• Have you experienced any medical problems during pregnancy? Have you ever had gestational hypertension?

Family history
Information about the patient’s blood relatives may suggest a specific cardiac problem. Ask him if anyone in his family has ever had hypertension, myocardial infarction (MI), cardiomyopathy, diabetes mellitus, coronary artery disease (CAD), vascular disease, hyperlipidemia, or sudden death. Ask how old the family member was when he or she died.

Lifestyle patterns
Always consider the patient’s cultural and social background when planning care. Note the patient’s education level. What’s his occupation and employment status? What kind of support system does he have? Does he live alone or with someone? Does he have any hobbies? How does he view his illness? Assess the patient’s self-image as you gather this information.

Cardiovascular disorders: Physical examination

Focus topic: Cardiovascular disorders

The first step in the physical examination is to assess the factors that reflect cardiovascular function, including vital signs and physical appearance. After examining these factors, you may assess the patient’s cardiovascular system using inspection, palpation, percussion, and auscultation.

Alter to fit

Focus topic: Cardiovascular disorders

Combine parts of the assessment, as needed, to conserve time and the patient’s energy. If the patient is experiencing cardiovascular difficulties, alter the order of your assessment as needed. For example, if he complains of chest pain and dyspnea, quickly check his vital signs and then auscultate the heart. If a female patient feels embarrassed about exposing her chest, explain each assessment step beforehand, use drapes appropriately, and expose only the area being assessed at the moment.

Vital signs
Assessing vital signs includes measuring temperature, blood pressure, pulse rate, and respiration.

Temperature
Temperature change can result from:
• cardiovascular inflammation or infection (higher than normal temperature)
• increased metabolism, which heightens cardiac workload (higher than normal temperature)
• poor perfusion and certain metabolic disorders such as hypothyroidism (lower than normal temperature).

Blood pressure
According to the American Heart Association (AHA), three successive readings of blood pressure above 140/90 mm Hg indicate hypertension. However, emotional stress caused by physical examination may elevate blood pressure. If the patient’s blood pressure is high, allow him to relax for several minutes and then measure again to rule out stress.

Take two

Focus topic: Cardiovascular disorders

When assessing a patient’s blood pressure for the first time, take measurements in both arms and use an appropriate-sized cuff. A difference of 10 mm Hg or more between arms may indicate thoracic outlet syndrome or other forms of arterial obstruction.

Pulse rate
If you suspect cardiac disease, auscultate an apical pulse for 1 full minute to detect any arrhythmias. Normally, an adult’s pulse ranges from 60 to 100 beats/minute. Its rhythm should feel regular, except for a subtle slowing on expiration, caused by changes in intrathoracic pressure and vagal response. Note whether the pulse feels weak, normal, or bounding.

Respiration
Observe for eupnea — a regular, unlabored, and bilaterally equal breathing pattern. Tachypnea may indicate low cardiac output. Dyspnea, a possible indicator of heart failure, may not be evident at rest. However, the patient may pause after only a few words to take a breath. A Cheyne-Stokes respiratory pattern may accompany severe heart failure, although it’s more commonly associated with coma. Shallow breathing may accompany acute pericarditis as the patient attempts to reduce the pain associated with deep respirations.

Physical appearance
Observe the patient’s general appearance, noting:
• weight and muscle composition
• skin turgor, integrity, and color
• energy level
• appearance compared with age
• comfort level or apparent level of anxiety.

Out on a limb

Focus topic: Cardiovascular disorders

Inspect the hair on the patient’s limbs. Hair should be distributed symmetrically and should grow thicker on the anterior surface of the arms and legs. If not, it may indicate diminished arterial blood flow to the arms and legs.
Note whether the length of the arms and legs is proportionate to the length of the trunk. Long, thin arms and legs may indicate Marfan syndrome, a congenital disorder that causes cardiovascular problems, such as aortic dissection, aortic valve incompetence, and car dio myopathy.

In the pink

Focus topic: Cardiovascular disorders

Fingernails normally appear pinkish with no markings. A bluish color in the nail beds indicates peripheral cyanosis. To estimate the rate of peripheral blood flow, assess the capillary refill in the fingernails or toenails by applying pressure to the nail for 5 seconds, then assessing the time it takes for color to return. In a patient with a good arterial supply, color should return in less than 3 seconds. Delayed capillary refill suggests reduced circulation to that area, a sign of low cardiac output that may lead to arterial insufficiency.

Inspection
Inspect the patient’s chest and thorax. Expose the anterior chest and observe its general appearance. Normally, the lateral diameter is twice the size of the anteroposterior diameter. Note any deviations from typical chest shape.

Go for the jugular

Focus topic: Cardiovascular disorders

When the patient is in a supine position, the jugular veins normally protrude; when the patient stands, the jugular veins normally lie flat. To check for jugular vein distention, place the patient in semi-Fowler’s position with his head turned slightly away from the side you’re examining. Use tangential lighting (lighting from the side) to cast small shadows along the neck. This will let you see pulse wave movement more easily. If jugular veins appear distended, it indicates high right atrial pressure and an increase in fluid volume caused by right heart dysfunction.

Cardiovascular disorders

Precordium pulsations

Focus topic: Cardiovascular disorders

Using tangential lighting, watch for chest wall movement, visible pulsations, and exaggerated lifts or heaves (strong outward thrusts over the chest during systole) in all areas of the precordium. Ask an obese patient or a patient with large breasts to sit during inspection to bring the heart closer to the anterior chest wall and make pulsations more noticeable.

Impulsive heart

Focus topic: Cardiovascular disorders

Normally, you’ll see pulsations at the point of maximal impulse of the apical impulse (pulsation at the apex of the heart). The apical impulse normally appears in the fifth intercostal space at or just medial to the midclavicular line. This impulse reflects the location and size of the heart, especially of the left ventricle. In thin adults and in children, you may see a slight sternal movement and pulsations over the pulmonary arteries or the aorta as well as visible pulsations in the epigastric area.

Cardiovascular disorders

Palpation
Palpate the peripheral pulses and precordium. Make sure the patient is positioned comfortably, draped appropriately, and kept warm. Also, warm your hands and remember to use gentle to moderate pressure.

Feel the flow

Focus topic: Cardiovascular disorders

You’ll already have palpated the radial pulse during your assessment of the patient’s vital signs. You’ll still need to palpate the other major pulse points to assess blood flow to the tissues. Because the larger central arteries (the carotids) lie closer to the heart, they have slightly higher pressures than the peripheral arteries, allowing you to palpate them more easily. Palpate only one carotid artery at a time; simultaneous palpation can slow the pulse or decrease blood pressure, causing the patient to faint. After palpating the carotids, continue on to the brachial, radial, femoral, popliteal, dorsalis pedis, and posterior tibial pulses. These arteries are close to the body surface and lie over bones, making palpation easier.

A gentle touch

Focus topic: Cardiovascular disorders

Press gently over these pulse sites; excess pressure can obliterate the pulsation, making the pulse appear absent. Look for the following ch aracteristics:
• pulse rate — varies with age and other factors (usually 60 to 100 beats/minute in adults)
• pulse rhythm — regular
• symmetry — equally strong bilateral pulses
• contour — smooth, wavelike (upstroke and downstroke) pulse flow
• strength — easily palpated pulses (strong finger pressure required to obliterate pulse).

Making the grade

Focus topic: Cardiovascular disorders

Pulses are graded on a numeric scale:
• 4+ is bounding.
• 3+ is increased.
• 2+ is normal.
• 1+ is weak.
• 0 is absent.

Percussion
As a medical-surgical nurse, you won’t routinely percuss the heart. If you note an abnormality in your overall assessment, check the patient’s record for a chest X-ray because it provides more accurate information and usually eliminates the need for percussion. Also, lung problems, which commonly accompany cardiovascular disorders, reduce the accuracy of percussion. However, percussion of the abdomen of a patient with right-sided heart failure may reveal dullness that extends several centimeters below the margin of the right ribs, indicating an enlarged liver.

Auscultation
The cardiovascular system requires more auscultation than any other body system.

Cardiovascular disorders

Auscultation aficionado

Focus topic: Cardiovascular disorders

Heart sounds are auscultated in the precordium. Identifying normal heart sounds, rates, and rhythms isn’t routine practice for the medical-surgical nurse, but it’s certainly a valuable skill to develop. Even so, expect some difficulty. Even with a stethoscope, the amount of tissue between the source of the sound and the outer chest wall can affect what you hear. Fat, muscle, and air tend to reduce sound transmission. When auscultating an obese patient or a patient with a muscular chest wall or hyperinflated lungs, sounds may seem distant.

See the sites

Focus topic: Cardiovascular disorders

First, identify cardiac auscultation sites. These include aortic, pulmonic, tricuspid, and mitral areas. Most normal heart sounds result from vibrations created by the opening and closing of the heart valves. When valves close, they suddenly terminate the motion of blood; when valves open, they accelerate the motion of blood. This sudden deceleration or acceleration produces heart sounds. Auscultation sites don’t lie directly over the valves but over the pathways the blood takes as it flows through chambers and valves.

Cardiovascular disorders

Sound it out

Focus topic: Cardiovascular disorders

Next, listen for a few cycles to become accustomed to the rate and rhythm of the sounds. You’ll differentiate heart sounds by their pitch (frequency), intensity (loudness), duration, quality (such as musical or harsh), location, and radiation. The timing of heart sounds in relation to the cardiac cycle is particularly important. Two sounds normally occur: S1 and S2. They have a relatively high pitch and are separated by a silent period. Normal heart sounds last only a fraction of a second, followed by slightly longer periods of silence. Listen for:
• S1 — the lub of lub-dub — which occurs at the beginning of systole when mitral and tricuspid valves close and blood is ejected into the circulation
• S2 — the dub of lub-dub — which occurs at the beginning of diastole when aortic and pulmonic valves close (louder in the aortic and pulmonary chest areas), coinciding with the pulse down stroke and followed by a silent period that normally exceeds the pause between S1 and S2.

Compare and contrast

Focus topic: Cardiovascular disorders

At each auscultatory site, use the diaphragm to listen closely to S1 and S2 and compare them. Then auscultate again, using the bell of the stethoscope. If you hear any sounds during the diastolic or systolic period or any variations in S1 or S2, document the characteristics of the sound. Note the auscultatory site and the part of the cardiac cycle during which it occurred. If you have difficulty identifying normal heart sounds, palpate the patient’s carotid artery with your stethoscope over the apex of the heart. The heart sound you hear at the time of the carotid pulse is S1.

Abnormal findings
Auscultation may also reveal the third and fourth heart sounds as well as a summation gallop, murmur, click, snap, or rub.

Ridin’ 3 white horses

Focus topic: Cardiovascular disorders

Also known as S3 or ventricular gallop, the third heart sound is a low-pitched noise heard best by placing the bell of the stethoscope at the apex of the heart. Its rhythm resembles a horse galloping, and its cadence resembles the word “Ken-tuc-ky” (lub-dub-by). Listen for S3 with the patient in a supine or leftlateral decubitus position.
An S3 usually occurs during early diastole to mid-diastole, at the end of the passive-filling phase of either ventricle. Listen for this sound immediately after S2. It may signify that the ventricle isn’t compliant enough to accept the filling volume without additional force. You can hear noncompliance in the right ventricle in the tricuspid area, and in the mitral area if the left ventricle is noncompliant. You may also be able to palpate a heave when the sound occurs.

Whoa, Nellie

Focus topic: Cardiovascular disorders

An S4 is an abnormal heart sound that occurs late in diastole, just before the pulse upstroke. It immediately precedes the S1 of the next cycle and is associated with acceleration and deceleration of blood entering a chamber that resists additional filling. Known as atrial gallop or presystolic gallop, it occurs during atrial contraction.
The S4 shares the same cadence as the word “Ten-nes-see” (le-lub-dub). Heard best with the bell of the stethoscope and with the patient in a supineposition, S4 may occur in the tricuspid or mitral area, depending on which ventricle is dysfunctional.

To sum up: A full stable

Focus topic: Cardiovascular disorders

Occasionally, a patient may have both a third and a fourth heart sound. When this happens, S3 and S4 occur so closely together that they appear to be one sound, called summation gallop. Auscultation may reveal two separate abnormal heart sounds and two normal sounds. In this case, the patient usually has tachycardia and a shorter diastolic phase.

Murmuring brook

Focus topic: Cardiovascular disorders

Longer than a heart sound, a murmur occurs as a vibrating, blowing, whistling, or rumbling noise. Just as water in a stream “babbles” as it passes through a narrow point, turbulent blood flow may produce a murmur. If you detect a murmur, identify its loudest location, pinpoint the time it occurs during the cardiac cycle, and describe its pitch, pattern, quality, and intensity.

Clicking cusps

Focus topic: Cardiovascular disorders

Clicks are high-pitched abnormal heart sounds that result from tensing of the chordae tendineae structures and mitral valve cusps. Initially, the mitral valve closes securely, but then a large cusp prolapses into the left atrium, causing the sound. The click usually precedes a late systolic murmur caused by regurgitation of a little blood from the left ventricle into the left atrium. Clicks occur in 5% to 10% of young adults and affect more women than men. To detect the high-pitched click of mitral valve prolapse, place the stethoscope diaphragm at the heart’s apex and listen during midsystole to late systole. To enhance the sound, change the patient’s position to sitting or standing, and listen along the lower left sternal border (Erb’s point).

Sternal snaps

Focus topic: Cardiovascular disorders

Place the stethoscope diaphragm medial to the apex along the lower left sternal border to detect a possible opening snap immediately after S2. This sound results from a stenotic valve (a valve that’s constricted or narrowed) attempting to open. The snap resembles the normal S1 and S2 in quality, and its high pitch helps differentiate it from an S3. Because the opening snap may accompany mitral or tricuspid stenosis, it usually precedes a middiastolic to late diastolic murmur (classic sign of stenosis).

Rub-a-lub-dub

Focus topic: Cardiovascular disorders

To detect a pericardial friction rub, use the diaphragm of the stethoscope to auscultate in the third left intercostal space along the lower left sternal border. Listen for a harsh, scratchy, scraping, or squeaking sound that occurs throughout systole, diastole, or both. To enhance the sound, have the patient sit upright and lean forward or exhale. A rub usually indicates pericarditis.

Inaudible arteries

Focus topic: Cardiovascular disorders

Auscultate the carotid, femoral, and popliteal arteries as well as the abdominal aorta. Over the carotid, femoral, and popliteal arteries, auscultation should reveal no abnormal sounds; over the abdominal aorta, it may detect bowel sounds but no abnormal vascular sounds.

That bruit is brutal

Focus topic: Cardiovascular disorders

During auscultation of the central and peripheral arteries, you may notice a bruit — a sound caused by turbulent blood flow. A bruit heard over the aorta or the carotid, femoral, popliteal, or brachial arteries can indicate turbulent blood flow caused by tortuous vessels, obstructions, aneurysms (vessels dilated because of weak walls), or dissections (tears in layers of the arterial wall).

Cardiovascular disorders

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