NCLEX: Caring for the Client with Disorders of the Cardiovascular System

Terms you’ll need to understand:
Aneurysms
Angina pectoris
Angioplasty
Artherosclerosis
Blood pressure
Buerger’s Disease
Cardiac catheterization
Cardiac tamponade
Cardiopulmonary resuscitation
Cholesterol
Conduction system of the heart
Congestive heart failure
Coronary artery bypass graft
Defribulation
Diastole
Electrocardiogram
Heart block
Hypertension
Implantable cardioverter
Myocardial infarction
Pacemaker
Raynaud’s
Systole
Thrombophlebitis
Varicose veins
Ventricular fibrillation
Ventricular tachycardia

Nursing skills you’ll need to master:
Performing cardio pulmonary resuscitation (CPR)
Monitoring central venous pressure
Monitoring blood pressure
Interpreting electrocardiography (ECG)

The cardiovascular system is comprised of the heart and blood vessels and is responsible for the transport of oxygen and nutrients to organ systems of the body. The heart is a cone-shaped organ made up of four chambers. The right side of the heart receives deoxygenated venous blood from the periphery by way of the superior and inferior venae cavae. The left side of the heart receives blood from the lungs and pumps the oxygenated blood to the body.
The blood vessels are divided into arteries and veins. Arteries transport oxygenated blood and veins transport deoxygenated blood. In this chapter, you will discover diseases that affect the cardiovascular system, the treatment of these diseases, and the affects on the client’s general health status.

Hypertension
Blood pressure is the force of blood exerted on the vessel walls. Systolic pressure is the pressure during the contraction phase of the heart and is evaluated as the top number of the blood pressure reading. Diastolic pressure is the pressure during the relaxation phase of the heart and is evaluated as the lower number of the blood pressure reading. A diagnosis of hypertension is made by a blood pressure value greater than 140/90 obtained on two separate occasions with the client sitting, standing, and lying. In clients with diabetes, a reading of 130/85 or higher is considered to be hypertension.
Accuracy of the BP reading depends on the correct selection of cuff size. The bladder of the blood pressure cuff size should be sufficient to encircle the arm or thigh. According to the American Heart Association, the bladder width should be approximately 40% of the circumference or 20% wider than the diameter of the midpoint of the extremity. A blood pressure cuff that’s too small yields a false high reading, whereas a blood pressure cuff that’s too large yields a false low reading.
Hypertension is classified as either primary or secondary. Primary hypertension, or essential hypertension, develops without apparent cause; secondary hypertension develops as a result of another illness or condition. Symptoms associated with secondary hypertension are improved by appropriate treatment of the contributing illness. Blood pressure fluctuates with exercise, stress, changes in position, and changes in blood volume. Medications such as oral contraceptives and bronchodilators can also cause elevations in blood pressure. Often the client with hypertension will have no symptoms at all or might complain of an early morning headache and fatigue. This silent killer, if left untreated, can lead to coronary disease, renal disease, strokes, and other life-threatening illnesses.

Management of hypertension includes a program of diet and exercise. If the client’s cholesterol level is elevated, a low-fat, low-cholesterol diet is ordered.
The serum cholesterol levels should be less than 200 mg/dl.

Medications Used to Treat Hypertension
Should diet and exercise prove unsuccessful in lowering the blood pressure, the doctor might decide to prescribe medications such as diuretics or antihypertensives.

Hypertension Drugs


These drugs can be used alone or in conjunction with one another. Diuretics and vasodilators are often given in combination to lower blood pressure through diuresis and vasodilation. Hypertensive crises exist when the diastolic blood pressure reaches 140. Malignant hypertension is managed with administration of IV Nitropress, Nitroglycerine, Nipride, Lasix, and other potent vasodilators such as Procardia.

Heart Block
The normal conduction system of the heart is comprised of the sinoatrial(SA) node located at the junction of the right atrium and the superior vena cava. This node is considered to be the main pacer of the heart rate. This area contains the pacing cells that initiate the contraction of the heart. The atrioventricular (AV) node is located in the interventricular septum and receives the impulse and transmits it on to the Bundle of His, which extends down through the ventricular septum and merges with the Purkinje fibers in the lower portion of the ventricles.

Anatomical drawing of the heart.


Heart block can occur as a results of structural changes in the conduction system, such as tumors, myocardial infarctions, coronary artery disease, infections of the heart, or toxic effects of drugs such as Digitalis. Heart block occurs when there is a problem with the conduction system of the heart.
First-degree AV block occurs when the SA node continues to function normally but transmission of the impulse fails. Because of the conduction dysfunction and ventricular depolarization, the heart beats irregularly. These clients are usually asymptomatic and all impulses eventually reach the ventricles. Second-degree heart block is a block in which impulses reach the ventricles but others do not. In third-degree heart block or complete heart, none of the sinus impulses reach the ventricle. This results in erratic heart rates where the sinus node and the atrioventricular nodes are beating independently. The result of this type of heart block can be hypotension, seizures, cerebral ischemia, or cardiac arrest. Detection of a heart block is made by assessing the electrocardiogram.

A normal electrocardiogram.


The P wave as shown in the graph is the SA node firing, the QRS complex is the contraction phase of the heart, and the T wave is the repolerization of the heart.

Toxicity to Medications
Toxicity to medications, such as Digitalis, can be associated with heart block.
Clients taking Digitalis should be taught to check their pulse rate and to return to the physician for regular evaluation of their Digitalis level. The therapeutic level for Digitalis is 0.9–1.2 ng/ml. If the client’s blood level of Digitalis exceeds 2.0 ng/ml, the client is considered to be toxic. Clients with Digitalis toxicity often complain of nausea, vomiting, and seeing halos around lights. A resting pulse rate of less than 60 bpm in the adult client, less than 80 bpm in the child, and less than 100 in the neonatal client should alert the nurse to the possibility of toxicity. Treatment for Digitalis toxicity includes checking the potassium level because hypokalemia can contribute to Digitalis toxicity. The physician often will order potassium be given IV or orally and that the Digitalis be held until serum levels return to normal.
Other medications, such as Isuprel or Atropine, and Digibind are frequently ordered to increase the heart rate. A high fiber diet will also be ordered because constipation contributes to Digitalis toxicity.

Malfunction of the Conduction System
Because a malfunction of the conduction system of the heart is the most common cause for heart block, a pacing mechanism is frequently implanted to facilitate conduction. Pacemakers can be permanent or temporary and be categorized as demand or set. A demand pacemaker initiates an impulse if the client’s heart rate fails below the prescribed beats per minute. A set pacemaker overrides the heart’s own conduction system and delivers an impulse at the rate set by the physician. Frequently, pacemakers are also combined with an internal defibrillation device.

Permanent Pacemakers/Internal Defibrillators: What the Client Should Know
Clients with internal defibrillators or pacemakers should be taught to avoid direct contact with electrical equipment. Clients should be instructed to
- Wear a medic alert stating that a pacemaker/internal defibrillator is implanted. Identification will alert the healthcare worker so alterations in care can be made.
- Take her pulse for 1 full minute and report the rate to the physician.
- Avoid applying pressure over the pacemaker. Pressure on the defibrilla- tor or pacemaker can interfere with the electrical leads.
- Inform the dentist of the presence of a pacemaker because electrical devices are often used in dentistry.
- Avoid having a magnetic resonance imaging (MRI). Magnetic resonance interferes with the electrical impulse of the implant.
- Avoid close contact with electrical appliances, electrical or gasoline engines, transmitter towers, antitheft devices, metal detectors, and welding equipment because they can interfere with conduction.
- Be careful when using microwaves. Microwaves are generally safe for use, but the client should be taught to stand approximately 5 feet away from the device while cooking.
- Report fever, redness, swelling, or soreness at the implantation site.
- If beeping tones are heard coming from the internal defibrillator, imme- diately move away from any electromagnetic source. Stand clear from other people because shock can affect anyone touching the client during defibrillation.
- Report dizziness, fainting, weakness, blackouts, or a rapid pulse rate.

The client will most likely be told not to drive a car for approximately 6 months after the internal defibrillator is inserted to evaluate any dysrhythmias.
- Report persistent hiccupping because this can indicate misfiring of the pacemaker/internal defibrillator.

Myocardial Infarction
When there is a disruption in blood supply to the myocardium, the client is considered to have had a myocardial infarction. Factors contributing to diminished blood flow to the heart include arteriosclerosis, emboli, thrombus, shock, and hemorrhage. If circulation is not quickly restored to the heart, the muscle becomes necrotic. Hypoxia from ischemia can lead to vasodilation of blood vessels. Acidosis associated with electrolyte imbalances often occurs, and the client can slip into cardiogenic shock. The most common site for a myocardial infarction is the left ventricle. Only 10% of clients report the classic symptoms of a myocardial infarction. Women often fail to report chest pain and, if they do, they might tell the nurse that the pain is beneath the shoulder or in the back. Clients with diabetes have fewer pain receptors and might report little or no pain.
The most commonly reported signs and symptoms associated with myocardial infarction include
- Substernal pain or pain over the precordium of a duration greater than 15 minutes
- Pain that is described as heavy, vise-like, and radiating down the left arm
- Pain that begins spontaneously and is not relieved by nitroglycerin or rest
- Pain that radiates to the jaw and neck
- Pain that is accompanied by shortness of breath, pallor, diaphoresis, dizziness, nausea, and vomiting
- Increased heart rate, decreased blood pressure, increased temperature, and increased respiratory rate

Angina pectoris occurs when there are vasospasms. This pain is relieved by nitroglycerine. The client should be taught to take one nitroglycerine tablet sublingually every 5 minutes. If the first tablet does not relieve the pain, a second can be taken, and if the pain is still not relieved, a third can be taken. If, however, the pain is not relieved after taking three tablets, one every 5 minutes, the client should come directly to the hospital or call an ambulance. The client should be taught to replenish his supply every 6 months and protect the pills from light by leaving them in the brown bottle. The cotton should be removed from the bottle because it will decrease the tablets’ effectiveness. Most physicians recommend that the client take one 365 mg aspirin at the first sign of chest pain. Aspirin has an anticoagulant effect and decreases the clotting associated with heart attacks.
The nurse must always wear gloves when applying nitroglycerine cream or patches to the client. Clip hair with scissors or shave, but do not abrade area.

Diagnosis of Myocardial Infarction
The diagnosis of a myocardial infarction is made by looking at both the electrocardiogram and the cardiac enzymes. The following are the most commonly used diagnostic tools for determining the type and severity of the attack:
- Electrocardiogram (ECG), which frequently shows dysrhythmias
- Serum enzymes and isoenzymes

Other tests that are useful in providing a complete picture of the client’s condition are white blood cell count (WBC), sedimentations rate, and blood urea nitrogen (BUN).
The best serum enzymes diagnostic is the creatine kinase (CK-MB) diagnostic. This enzyme is released when there is damage to the myocaridium.
The Troponin T and 1 are specific to striated muscle and are often used to determine the severity of the attack. C-reactive protein (CRP) levels are used with the CK-MB to determine whether the client has had an acute MI and the severity of the attack. Lactice acid dehydrogenase (LDH) is a nonspecific enzyme that is elevated with any muscle trauma.

Management of Myocardial Infarction Clients
Management of myocardial infarction clients includes monitoring of blood pressure, oxygen levels, and pulmonary artery wedge pressures. Because the blood pressure can fall rapidly, medications such as dopamine is prescribed.

Other medications are ordered to relieve pain and to vasodilate the coronary vessels—for example, morphine sulfate IV is ordered for pain.
Thrombolytics, such as streptokinase, will most likely be ordered. Early diagnosis and treatment significantly improve the client’s prognosis.
Clients suffering a myocardial infarction can present with dysrhythmias.
Ventricular dysrhythmias such as ventricular tachycardia or fibrillation lead to stand-still and death if not treated quickly.

Ventricular Tachycardia
Ventricular tachycardia is a rapid irregular rhythm absence of a p-wave.
Usually the rate exceeds 140–180 bpm. The SA node continues to discharge independently of the ventricle. Ventricular tachycardia is often associated with valvular heart disease, heart failure, hypomagnesium, hypotension, and ventricular aneurysms.

Evidence of ventricular tachycardia.


Ventricular tachycardia is treated with oxygen and medication. Amiodarone (Cordarone), procainamide (Pronestyl), or magnesium sulfate are given to slow the rate and stabilize the rhythm. Lidocaine has long been established for the treatment of ventricular tachycardia; however, it should not be used in an acute MI client. Heparin is also ordered to prevent further thrombus formation but is not generally ordered with clients taking streptokinase.

Ventricular Fibrillation
Ventricular fibrillation (V-fib) is the primary mechanism associated with sudden cardiac arrest. This disorganized chaotic rhythm results in a lack of pumping activity of the heart. Without effective pumping, no oxygen is sent to the brain and other vital organs. If this condition is not corrected quickly, the client’s heart stops beating and asystole is seen on the ECG. The client quickly becomes faint, loses consciousness, and becomes pulseless.
Hypotension or a lack of blood pressure and heart sounds are present.

Ventricular Fibrillation (V Fib)
'sawtooth'

Ventricular fibrillation diagram.
The chaotic rhythms typical with V-fib.


Treatment of ventricular fibrillation is to defibrillate the client starting with 200 Joules. Three quick, successive shocks are delivered with the third at 360 Joules. If a defibrillator is not readily available, a precordial thump can be delivered. Administration of oxygen and antidysrhythmic medications such as epinephrine, amiodarone, procainamide, lidocaine, or magnesium sulfate are ordered. If cardiac arrest occurs, the nurse should initiate cardiopulmonary resusicitation and be ready to administer first-line drugs such as epinephrine.
Cardiac catheterization is used to detect blockages associated with myocardial infarctions and dysrthymias. Cardiac catheterization, as with any other dye procedure, requires a permit. This procedure can also accompany percutaneous transluminal coronary angioplasty. Prior to and following this procedure, the nurse should
- Assess for allergy to iodine or shell fish.
- Maintain the client on bed rest with the leg straight.
- Maintain pressure on the access site for at least 5 minutes or until no signs of bleeding are noted. Many cardiologist use a device called Angio Seals to prevent bleeding at the insertion site. The device creates a mechanical seal anchoring a collagen sponge to the site. The sponge absorbs in 60–90 days.
- Use pressure dressing and/or ice packs to control bleeding.
- Check distal pulses because diminished pulses can indicate a hematoma and should be reported immediately.
- Force fluids to clear dye from the body.

If the client is not a candidate for angioplasty, a coronary artery bypass graft might be performed. The family should be instructed that the client will return to the intensive care unit with several tubes and monitors. The client will have chest tubes and a mediastinal tube to drain fluid and to reinflate the lungs. If the client is bleeding and blood is not drained from the mediastinal area, fluid accumulates around the heart. This is known as cardiac tamponade.
If this occurs, the myocardium becomes compressed and the accumulated fluid prevents the filling of the ventricles and decreases cardiac output.
A Swan-Ganz catheter for monitoring central venous pressure, pulmonary artery wedge pressure monitor, and radial arterial blood pressure monitor is inserted to measure vital changes in the client’s condition. An ECG monitor and oxygen saturation monitor are also used. Other tubes include a nasogastric tube to decompress the stomach, a endotracheal tube to assist in ventilation, and a Foley catheter to measure hourly output.
The client should be given small, frequent meals. The diet should be low in sodium, fat, and cholesterol. Adequate amounts of fluid and fiber are encouraged to prevent constipation, and stool softeners are also ordered. Post-MI teaching should stress the importance of a regular program of exercise, stress reduction, and cessation of smoking. Because caffeine causes vasoconstriction, caffeine intake should be limited. The client can resume sexual activity in 6 weeks or when he is able to climb a flight of stairs without experiencing chest pain. Medications such as Viagra are discouraged and should not be taken within 24 hours of taking a nitrite. Clients should be taught not to perform valsalva maneuver or bending at the waist to retrieve items from the floor. Placing items in top drawers helps to prevent increased intrathoracic pressure. The client will probably be discharged on an anticoagulant such as enoxaparin (Lovenox) or sodium warfarin (Coumadin).
Anticoagulants such as heparin are used. The nurse should check the partial thromoplastin time (PTT). The normal control level is approximately 30–60 seconds. The therapeutic bleeding time should be from one and a half to two times the control. The medication should be injected in the abdomen 2'' from the umbilicus using a tuberculin syringe. Do not aspirate or massage. The antidote for heparin derivatives is protamine sulfate.
If Coumadin (sodium warfarin) is ordered, the nurse should check the PT or protime.
The control level for a protime is 10–12 seconds. The therapeutic level for Coumadin should be from one and a half to two times the control. The antidote for Coumadin is vitamin K. The international normalizing ratio (INR) is done for oral anticoagulants.
The therapeutic range is 2–3. If the level exceeds 7, watch for spontaneous bleeding.

Buerger’s Disease
Buerger’s disease (thromboangilitis obliterans) results when spasms of the arteries and veins occur primarily in the lower extremities. These spasms result in blood clot formations and eventually destruction of the vessels.
Symptoms associates with Buerger’s include pallor of the extremities progressing to cyanosis, pain, and paresthesia. As time progresses, toplic changes occur in the extremities. Management of the client with Buerger’s involves the use of Buerger-Allen exercises, vasodilators, and oxygenation. The client should be encouraged to stop smoking.

Thrombophlebitis
Thrombophlebitis occurs when an inflammation of a vein with formation of a clot occurs. Most thrombophlebitis occurs in the lower extremities, with the saphenous vein being the most common vein affected. Homan’s sign is an assessment tool used for many years by healthcare workers to detect deep vein thrombi. It is considered positive if the client complains of pain on dorsiflexion of the foot. Homan’s sign should not be performed routinely because it can cause a clot to be dislodged and lead to pulmonary emboli. If a diagnosis of thrombophlebitis is made, the client should be placed on bed rest with warm, moist compresses to the leg. An anticoagulant is ordered, and the client is monitored for complications such as cellulitis. If cellulitis is present, antibiotics are ordered.
Antithrombolitic stockings or compression devices are ordered to prevent venous stasis. When antithrombolitic stockings are applied, the client should be in bed for a minimum of 30 minutes prior to applying the stockings. The circumference and length of the extremity should be measured to prevent rolling down of the stocking and a tourniquet effect.

Raynaud’s
Raynaud’s Syndrome occurs when there are vascular vasospasms brought on by exposure to cold. The most commonly effected areas are the hands, nose, and ears. Management includes preventing exposure, stopping smoking, and using vasodilators. The client should be encouraged to wear mittens when outside in cold weather.

Aneurysms
An aneurysm is a ballooning of an artery. The greatest risk for these clients is rupture and hemorrhage. Aneurysms can occur in any artery in the body and can be due to congenital malformations or arteriosclerosis or be secondary to hypertension. The following are several types of aneurysms:
- Fusiform—This aneurysm affects the entire circumference of the artery.
- Saccular—This aneurysm is an outpouching affecting only one portion of the artery.
- Dissecting—This aneurysm results in bleeding into the wall of the vessel.

Frequently, the client with an abdominal aortic aneurysm complains of feeling her heart beating in her abdomen or lower back pain. Any such complaint should be further evaluated. On auscultation of the abdomen, a bruit can be heard. Diagnosis can be made by ultrasound, arteriogram, or abdominal x-rays.
If the aneurysm is found to be 6 centimeters or more, surgery should be scheduled. During surgery the aorta is clamped above and below and a donor vessel is anastamosed in place. When the client returns from surgery, pulses distal to the site should be assessed and urinary output should be checked.
Clients who are not candidates for surgery might elect to have stent placement to reinforce the weakened artery. These stents are threaded through an incision in the femoral artery, hold the artery open, and provide support for the weakened vessel.

Abdominal aortic aneurysm.


Congestive Heart Failure
When fluid accumulation occurs and the heart is no longer able to pump in an efficient manner, blood can back up. Most heart failure occurs when the left ventricle fails. When this occurs, the fluid backs up into the lungs, causing pulmonary edema. The signs of pulmonary edema are frothy, pink tinged sputum; shortness of breath; and orthopnea. Distended jugular veins might also be present. When right-sided congestive heart failure occurs, the blood backs up into the periphery. The nurse might also note signs of pitting edema. Pitting can be evaluated by pressing on the extremities and noting the degree of pitting, how far up the extremity the pitting occurs, and how long it takes to return to the surface. Treatment for congestive heart failure includes use of diuretics, Natrecor, Primacor, and cardiotonics. Morphine might also be ordered to manage pain.

Diagnostic Tests for Review
The following diagnostic test should be reviewed prior to taking the NCLEX exam:
- CBC—A complete blood count tells the nurse the level of oxygenation of the blood, particularly the hemoglobin and hematocrit.
- Chest x-ray—Chest x-rays and other x-rays tell the nurse whether the heart is enlarged or aneurysms are present.
- Arteriogram—Arteriography reveals the presence of blockages and abnormalities in the vascular system.
- Cardiac catheterization—A cardiac catheterization reveals blockages, turbulent flow, and arteriosclerotic heart disease.
- ECG interpretation—Indicates abnormalities in the rate and rhythm of the conductions system of the heart.
- Central venous pressure monitoring—CVP indicates fluid volume status.

Pharmacology Categories for Review
The following pharmacology categories should be reviewed prior to taking the NCLEX exam:
- Diurectics
- Cardiotonics
- Antihypertensives
- Anticoagulants
- Thrombolytics