102. CCA Study Notes: Cardiovascular System Disorders and Supporting Clients

The Big Picture

The cardiovascular system includes the heart and blood vessels. The heart pumps blood through the body. Blood brings oxygen, nutrients, and other substances to cells and carries waste products away.

Cardiovascular disorders affect the heart or blood vessels. Some conditions interfere with blood flow. Others affect blood pressure, heart rhythm, or the heart’s ability to pump normally. These disorders are leading causes of death in Canada.

This Topic also includes important client-support points. Some signs require immediate attention, while other care follows the client’s care plan.

Look for Nova Scotia CCA Notes throughout this page for current provincial guidance.

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Course Notes: Key Ideas You Need to Know

Cardiovascular System Basics

The heart and blood vessels work together to move blood throughout the body. Blood supplies cells with oxygen and nutrients and removes waste products.

Hypotension means low blood pressure. In this Topic, hypotension means a systolic pressure below 90 mm Hg and a diastolic pressure below 60 mm Hg. Severe dehydration may lead to severe hypotension and, in extreme situations, heart complications or death.

Dehydration

Dehydration means the amount of water in body tissues decreases because fluid output becomes greater than fluid intake.

The body naturally loses water through sweating, breathing, urination, bowel movements, tears, and saliva. Drinking fluids and eating foods that contain water replace lost fluid.

Common causes of dehydration include:

• low fluid intake
• vomiting
• diarrhea
• bleeding
• excessive sweating
• increased urine production
• excessive urination linked to conditions such as diabetes
• taking an incorrect dose of diuretics

Mild or Moderate Dehydration

Signs include:

• thirst
• dry or sticky mouth
• decreased urination
• dark yellow urine
• dry, cool skin
• headache
• muscle cramps

Severe Dehydration

Signs include:

• no urine production, called anuria, or concentrated dark urine
• very dry skin
• dizziness
• rapid heartbeat
• rapid breathing
• sunken eyes
• sleepiness, lack of energy, confusion, or irritability
• fainting

Older people, infants, and young children are especially susceptible to dehydration. Severe dehydration is a medical emergency and requires immediate treatment.

Dehydration and Potassium Loss

Severe dehydration sometimes involves dangerous potassium loss. Potassium, written as K⁺, helps maintain electrical activity in body cells, including cells in heart muscle.

Potassium leaves the body through vomit and diarrhea feces. Low potassium levels affect heart cells in particular and may lead to potentially lethal heart conditions.

People at risk include clients who have frequent vomiting and diarrhea for more than several days, cannot tolerate fluids, and become dehydrated. Risk also includes people who have eaten tainted food or water and people with bulimia nervosa who frequently purge or overuse laxatives.

A significant drop in blood potassium requires hospital treatment. Treatment includes an intravenous (IV) solution containing potassium replacement.

Dehydration in Infants and Young Children

Infants and young children are at risk for dehydration, and death from dehydration may happen quickly.

Report: Report liquid or watery stool immediately. Keep track of the number of wet diapers during 24 hours and report concerns immediately.

Fewer than six wet diapers in 24 hours may indicate dehydration. Signs in babies and young children include:

• dry mouth and tongue
• no tears when crying
• dry diapers for 3 hours
• sunken eyes, cheeks, or the soft spot on top of the skull
• sleepiness, lack of energy, or irritability

Dehydration in Older People

Dehydration is one of the most frequent causes of hospitalization after age 65. Several changes and conditions raise the risk.

Older people have less body water, less efficient kidney function, a reduced sense of thirst, and less ability to notice changes in body temperature. Eating less also reduces the amount of fluid received from food. Diabetes also increases dehydration risk.

Other risk factors include medications that increase urine production or sweating and decreased kidney function that reduces the body’s ability to conserve water. Some older people with dysphagia hesitate to drink because they fear choking.

Report: Report any signs of diarrhea immediately in an older person. Unrecognized and untreated dehydration may result in death.

Pathogens often cause diarrhea, so preventing infection spread is important. Always follow Standard Practices when coming into contact with stools.

Hypertension

Hypertension means persistently elevated blood pressure. In this Topic, it involves measurements above a systolic pressure of 140 mm Hg or a diastolic pressure of 90 mm Hg.

Elevated measurements must occur on two consecutive occasions ⓘ before they are considered a diagnosis of hypertension.

Causes

Narrowed blood vessels are a common cause. When vessels narrow, the heart must pump with more force to move blood through them.

Other causes include:

• kidney disorders
• head injuries
• complications of pregnancy
• tumours

Risk Factors

Risk factors include:

• Age: Blood pressure tends to rise with age, beginning at about age 35.
• Ethnicity: Hypertension occurs at statistically higher rates among Canadians of South Asian, Indigenous, or African descent.
• Family history: Risk rises when a parent has hypertension and increases when both parents have it.
• Obesity: Risk rises when excess weight is stored around the abdomen.
• Diabetes: People with diabetes have increased risk.
• Stress: Repeated exposure to stress may raise blood pressure.
• Alcohol: Excessive alcohol consumption raises blood pressure.
• Smoking: Cigarette smoking may contribute to hypertension.

Signs, Symptoms, and Complications

Hypertension may cause no signs or symptoms at first. Many people learn they have it during routine blood pressure checks.

As hypertension progresses, a person may report headache, blurred vision, or dizziness.

Hypertension may damage body organs. The heart may enlarge as it works harder. Blood vessels in the brain may burst and cause a stroke. Blood vessels in the eyes, kidneys, and other organs may also become damaged.

Complications include:

• stroke
• heart attack
• kidney failure
• blindness

Treatment and Risk Reduction

Medications lower blood pressure for some clients. Other measures include quitting smoking, exercising, and getting enough rest.

A physician often orders a sodium-restricted diet ⓘ. A low-calorie diet may also be ordered when the client is overweight.

Coronary Artery Disease

The coronary arteries supply the heart with blood containing oxygen and nutrients.

Coronary artery disease (CAD) involves coronary arteries that become narrowed or blocked. Atherosclerosis causes this narrowing through a buildup of cholesterol and other fatty substances along the inner artery walls.

As the arteries narrow or become blocked, blood flow to the heart slows or stops. The heart muscle then receives less oxygen and nutrients. Chest pain or a heart attack may result.

CAD Risk Factors

Risk factors include:

• hypertension
• high blood cholesterol
• lack of exercise
• obesity
• smoking
• excessive alcohol
• stress
• uncontrolled diabetes
• older age
• male gender
• family history of CAD

Treatment focuses on reducing risk factors where possible. Measures include weight loss, regular exercise, quitting smoking, maintaining a healthy diet, and controlling blood pressure and diabetes. Age, gender, and family history remain unchanged.

CABG, Angioplasty, and Stenting

Some clients undergo coronary artery bypass grafting (CABG). This surgery creates a new path around the diseased part of an artery, increasing blood flow to the heart.

Less invasive procedures include angioplasty and vascular stenting.

CABG	Stenting
Uses general anaesthesia	Uses local anaesthesia
Has a longer recovery time	Has a shorter recovery time
The beneficial effect lasts longer because arteries remain clear longer	The beneficial effect may be more limited
More invasive	Less invasive

Angina Pectoris

Angina pectoris is chest pain caused by ischemia, which means a lack of blood supply to the heart muscle. The ischemia is usually caused by an obstruction or spasm of the coronary arteries because of coronary artery disease. Clients with angina are at risk for a heart attack.

Physical exertion is the most common trigger. Other triggers include:

• emotional stress
• extreme cold or heat
• heavy meals
• alcohol
• smoking

What Angina Feels Like

Angina chest pain may feel like:

• heaviness
• tightness
• pressure

Pain usually occurs on the left side. Severe pain may last 2 to 15 minutes and may travel to the jaw, neck, shoulders, back, or arms.

Angina in the upper abdomen sometimes feels like indigestion or heartburn. Other symptoms include shortness of breath, nausea, sweating, dizziness or light-headedness, fatigue, and palpitations ⓘ.

Women, older people, and people with diabetes may experience symptoms that differ from the usual pattern.

The symptoms cause the client to stop activity and rest. Rest often relieves symptoms within 3 to 15 minutes because it lowers the heart’s need for oxygen. Normal blood flow is then achieved, which prevents heart damage.

Nitroglycerin and Emergency Action

Clients with angina are often prescribed nitroglycerin. Forms include tablets, ointment, patches, and sprays. The client carries the medication and takes a dose when an angina attack occurs.

Emergency action: If the client has taken the maximum amount of nitroglycerin and the pain does not improve, call emergency services and the supervisor.

Myocardial Infarction

Myocardial infarction (MI) means death of heart tissue because the heart does not receive enough oxygen after blood flow suddenly stops. Another name for an MI is a heart attack.

Atherosclerosis or a thrombus may block an artery and stop blood flow. Sudden cardiac death, also called cardiac arrest, may result. The damaged area of heart tissue may be small or large.

Other terms used for MI include coronary, coronary thrombosis, and coronary occlusion.

An estimated 1.6 million Canadians are living with heart disease or the effects of stroke, and 2.4 million Canadians are living with diagnosed heart disease.

Defibrillation and Cardiac Arrest

When defibrillation is used with cardiopulmonary resuscitation (CPR) during cardiac arrest, survival rates may rise above 50% when defibrillation occurs within the first few minutes.

For every 1-minute delay in defibrillation, the survival rate decreases by 7% to 10%.

Signs and Symptoms of MI

A person having an MI may experience:

• sudden, severe chest pain, usually on the left side
• crushing, stabbing, squeezing, tight, heavy, pressured, full, or burning chest pain
• pain that travels to the neck, jaw, arm, or other areas
• pain that is more severe and lasts longer than angina pain
• pain that does not improve with rest or nitroglycerin
• indigestion
• shortness of breath
• nausea or vomiting
• dizziness
• perspiration
• cyanosis, meaning bluish lips and nail beds caused by low oxygen in the blood
• cold, clammy skin
• low blood pressure
• weak, irregular pulse
• fear, anxiety, or a feeling of doom

Women may experience no pain. Nausea, sudden fatigue, or shortness of breath occur more often in women.

Early Warning Signs in Women

Some women, especially older women, experience early warning signs at least a month before an MI. These include:

• unusual fatigue
• sleep disturbances
• shortness of breath
• indigestion
• anxiety

Report: A support worker needs to report these symptoms to the supervisor.

An MI is an emergency. The average client waits almost 5 hours before getting help, and many clients deny they are having an MI.

Hospital Treatment and Recovery

Treatment focuses on relieving pain, stabilizing vital signs, giving oxygen, calming the client, and giving medications.

The client receives treatment in a coronary care unit (CCU), which has emergency equipment and medications for life-threatening complications. The client remains in the CCU for about 2 to 3 days, depending on the area, before transfer to another nursing unit once stable.

Activity increases gradually after an MI. Rehabilitation starts in the hospital and continues after the client returns home, with the goal of preventing another heart attack. It includes exercise and teaching about medications, diet changes, activity, and lifestyle changes.

Activities, including sexual activity, return to normal levels gradually. The client returns to work when advised by the physician.

Congestive Heart Failure

Congestive heart failure (CHF), also called heart failure, occurs when the heart does not pump blood normally. Blood backs up and excess fluid collects in body tissues.

CHF may affect the right side, left side, or both sides of the heart.

Right-Sided Heart Failure

The right side of the heart receives blood from body tissues and pumps it toward the lungs for oxygen.

With right-sided heart failure, blood backs up into the veins. Effects include:

• fluid buildup and weight gain
• pitting edema ⓘ in the feet and ankles
• enlarged neck veins
• an engorged liver with impaired function
• abdominal congestion
• loss of appetite
• abdominal pain
• eventual weight loss

Left-Sided Heart Failure

The left side of the heart receives blood from the lungs and pumps it to the rest of the body.

With left-sided heart failure, blood collects in lung tissue. Effects include:

• difficulty breathing, called dyspnea
• increased sputum ⓘ
• coughing
• gurgling sounds in the lungs
• worse breathing during activity or while lying down
• disrupted sleep
• waking with a feeling of suffocation
• fatigue
• weakness in the limbs

In advanced CHF, reduced oxygen reaching the brain may cause confusion and behaviour changes. Poor blood flow to the kidneys leads to impaired kidney function and low urine output.

CHF Treatment

Treatment includes medications that strengthen the heart and reduce excess fluid. A sodium-restricted diet and oxygen are also used.

Daily weight checks help identify weight gain, which is an early sign of fluid buildup. Most clients with CHF prefer the semi-Fowler’s or Fowler’s position because breathing feels easier.

Support Worker Care for CHF

A support worker may be involved in:

• helping the client maintain bed rest
• measuring intake and output
• measuring daily weight, ideally before eating and after voiding ⓘ
• helping restrict fluids when ordered by the physician
• assisting with transfers or ambulation ⓘ
• helping with self-care
• maintaining good positioning and body alignment according to the care plan ⓘ
• applying elastic stockings to reduce leg swelling

CHF in Children and Older People

Congenital heart defects may cause CHF in children. Congenital refers to being born with the condition.

Many older people develop CHF as the heart muscle weakens with age. Some need home care or long-term care.

Older people with CHF have increased risk of skin breakdown. Tissue swelling, poor circulation, and fragile skin contribute to pressure-ulcer risk. Effective skin care and regular position changes are essential.

Arrhythmias

An arrhythmia is an abnormal heart rhythm. It occurs when the heart’s electrical system malfunctions.

The heart may skip beats or produce extra beats. Some arrhythmias do not affect the client’s health, while more serious arrhythmias may cause:

• dizziness
• shortness of breath
• fainting
• death

Avoiding caffeine and alcohol sometimes prevents arrhythmias. Sources of caffeine listed in this Topic include coffee, tea, colas, and chocolate. Severe arrhythmias require medication.

Pacemakers

A pacemaker is an implanted medical device used to regulate the heartbeat in some arrhythmias. It monitors heart rate and gives small electric shocks when needed to stimulate heartbeats. Pacemaker batteries last several years.

Clients with pacemakers should avoid areas or equipment with strong electrical or magnetic fields. Examples include some microwaves, security systems, and therapeutic magnetic mattress pads.

Clients should ask their doctor about being around:

• cell phones and MP3 players
• high-tension wires
• metal detectors
• industrial welders
• electrical generators
• some medical equipment, including machines used for magnetic resonance imaging (MRI)

Phlebitis

Phlebitis means inflammation of a vein. It occurs most often in the legs.

Causes include:

• bacterial infection
• chemical irritation
• trauma
• lupus
• a genetic condition

Signs and symptoms include redness, warmth, pain, burning, and swelling.

CCA action: Provide supportive care according to the client’s care plan.

Thrombus and Embolus

A thrombus is a blood clot that forms inside a blood vessel.

A clot in a large blood vessel decreases blood flow. A clot in a small blood vessel may stop blood flow completely and lead to death of the tissue below the blockage.

A thrombus may form following:

• a stroke
• a heart attack
• deficiencies in the blood’s clotting ability
• long periods of inactivity, such as after surgery

A thrombus, or part of one, may break away and travel through the body. A travelling blood clot is called an embolus. An embolus may travel to the lungs and cause severe breathing problems and death.

Clients should be encouraged to keep active. Leg exercises are especially important for clients confined to bed. Follow the client’s care plan to reduce thrombus risk.

Supporting a Client With a Cardiovascular Disorder

Clients living with cardiovascular disorders may feel frightened, vulnerable, or afraid of dying.

Communicate With Empathy

Listen to the client and use empathy when speaking. This communicates respect.

Support Comfort

Use pain-reducing comfort measures. Maintain good body alignment and keep the surface under the client clean, dry, and free of wrinkles.

Report and document: Report and record any pain so the client can be kept comfortable and medicated according to the care plan.

Protect Confidentiality

Always follow confidentiality rules. Never discuss the client or the client’s personal details with anyone who is not involved in the client’s care.

Common Mix-Ups

Wrong Idea	Better Idea
Angina and an MI cause the same pain pattern.	Angina often improves with rest in 3 to 15 minutes. MI pain is more severe, lasts longer, and does not improve with rest or nitroglycerin.
Right-sided and left-sided heart failure cause the same fluid problems.	Right-sided failure causes blood to back up into veins and body tissues. Left-sided failure causes blood to collect in lung tissue.
A thrombus and an embolus mean exactly the same thing.	A thrombus forms in a blood vessel. An embolus is a clot that travels and lodges in another blood vessel.