Lecture 1-Heart Failure

8/6/2019 Lecture 1-Heart Failure

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Definition

By Mayo Clinic staff

Heart failure, also known as congestive heart failure (CHF), means your heart can't pump enoughblood to meet your body's needs. Over time, conditions such as narrowed arteries in your heart(coronary artery disease) or high blood pressure gradually leave your heart too weak or stiff to

fill and pump efficiently.

You can't reverse many conditions that lead to heart failure, but heart failure can often be treated

with good results. Medications can improve the signs and symptoms of heart failure. Lifestylechanges, such as exercising, reducing the salt in your diet, managing stress, treating depression,

and especially losing excess weight, can improve your quality of life.

The best way to prevent heart failure is to control risk factors and conditions that cause heart

failure, such as coronary artery disease, high blood pressure, high cholesterol, diabetes orobesity.

(http://www.heartfailure.org/eng_site)

-Heart failure is a progressive disorder in which damage to the heart causes weakening of the

cardiovascular system. It manifests by fluid congestion or inadequate blood flow to tissues. Heart failure

progresses by underlying heart injury or inappropriate responses of the body to heart impairment.

Symptoms and

Signs

Swollen Ankles or Legs

Swollen ankles or legs, known as peripheral edema, may be a result ofright-sided heart failure since flui

pumped to the lungs at an efficient rate. In right-sided heart failure, fluid backs up in the veins, leaks outcapillaries and accumulates in tissues. Also, a decrease in blood flow to the kidneys can lead to an increa

retention. Diuretics are often prescribed to get rid of this excess fluid and reduce the strain on the heart.

In the absence of heart failure, peripheral edema may commonly be due to obesity or venous insufficienstretched venous valves.


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Weight Gain or LossExcess fluid in the body may cause an increase in weight. Similarly, when excess fluid is excreted, your

fall. Weight increases by about two pounds for each extra quart of fluid. You may notice that your weighbefore you notice swelling of the ankles or extremities. Inform your doctor of changes of more than five

Causes of Heart Failure

For heart failure to occur, there must be an unresolved impairment of the heartthat compromises its ability to work as a pump. The source of this can be a cutoff

of blood supply, an increase in workload due to high blood pressure caused bynon-functioning valves or a genetic predisposition. Heart failure can be worsened

by a poor diet and lifestyle. Its development follows the scheme below:

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Conditions That May Lead To Heart Failure

Coronary Artery Disease (CAD)

This is the most common cause of heart failure in the U.S. today. CAD causingobstruction to the coronary arteries prevents blood flow and, therefore, oxygen

delivery to the heart. CAD is a manifestation of atherosclerosis, which can affect

any artery of the body. Risk factors for CAD also include smoking, highcholesterol, hypertension, and diabetes.

HypertensionThis is more commonly known as high blood pressure. It is a condition that is

treatable and simple to diagnose with a blood pressure cuff. Although mostindividuals will not have symptoms, hypertension is detected by a simple

measurement with a blood pressure cuff and stethoscope. It is also a risk factor forCAD, stroke, peripheral vascular disease, or kidney impairment.

Valvular Heart Disease

A condition that occurs when the valves between the chambers of the heart arefaulty, either due to birth defect or injury.

CardiomyopathyA disease of the heart muscle. This can be one of many varieties. It can arise

because of genetic causes, a viral infection, or consumption of toxins (lead,alcohol, etc.). In peripartum cardiomyopathy, women who have recently given

birth can develop heart muscle impairment. In many cases, the condition is called

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"idiopathic", which means it has occurred of uncertain origin or cause.

In addition to those causes above, the following factors also can play a role in

determining if heart failure will affect you:

1. family history of heart failure2. diabetes3. marked obesity4. heavy consumption of alcohol, or drug abuse5. failure to take medications6. large salt intake in diet7. sustained rapid heart rhythms

Many other conditions can actually simulate heart failure symptoms - it is

important to seek evaluation from a medical professional for a definitivediagnosis. Some of these are:

1. lung impairment2. anemia3. kidney impairment4. pericardial disease (rare)

Heart Failure and Your Circulation

Two important causes of heart failure are Coronary Artery Disease andHypertension.

Coronary Artery Disease (also known as CAD)

Cause

Coronary Artery Disease is a condition

where fatty deposits and cell-proliferation build-up in the arteriessupplying the heart muscle. These

plaques form commonly in a conditioncalled atherosclerosis. Genetic factors

or a diet of foods high in cholesterol orsaturated fat that result in high blood

cholesterol can increase your risk for


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this disease. Fatty deposits formsilently; no symptoms arise until they

are large enough to significantlyrestrict blood flow to an area of heart

muscle. When this occurs, angina

pectoris (chest tightness or discomfort)usually results. Normally a 70% orgreater blockage in the diameter of a

coronary artery will cause symptoms ofchest discomfort or pain with exercise.

An abrupt closure of a coronary artery

due to a blood clot forming (associatedwith a fissure of a plaque) can cause a

heart attack (or myocardial infarction).

Symptoms

Angina Pectoris - A constricting chestdiscomfort or pressure that can radiate

outward in the torso, left arm, neck andaw. Sustained symptoms at rest could

represent a heart attack.

Diagnosis

Screening tests for CAD are treadmilltesting, stress echocardiograms and

tracer studies. Coronary arteriographyis the gold standard for diagnosing

CAD. In this procedure a catheter isinserted into the leg or arm and guided

toward the opening of the blood vesselsthat supply the heart. A dye is then

injected directly into the coronaryarteries while x-ray movies are

recorded.

Treatment

Medical management includes:

y drugs to reduce the heart's needfor oxygen

y drugs to lower blood pressurey drugs that dilate the coronary

arteries

y drugs to reduce the amount ofcholesterol in the body

Other alternatives are coronary

angioplasty and stent implantation orcoronary artery bypass grafts.

Hypertension (High Blood Pressure)

Cause

Blood pressure refers to the pressure ofblood against the walls of arteries and

is measured in units of millimeters ofmercury (mmHg), which is a reference

to the fluid historically used with bloodpressure cuffs. Blood pressure is

always measured by two numbers onthis scale. The range of the first

Symptoms

Usually none, but headaches andflushing are sometimes evident.

Diagnosis

Blood pressure cuff(sphygmomanometer), Chest X-ray and

echocardiogram (to observe


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number is usually 100-140 mmHg,which is referred to as systolic (the

peak pressure in the arteries after theheart contracts). The range of the

second number is usually 60-90 mmHg

and is referred to as diastolic (theminimum pressure reached in thearteries when the heart relaxes just

before the next contraction). The usualcause of hypertension is not known -

the brain's "set-point" for a usual BPincreases. Uncommonly, renal artery

stenosis (a blockage of the arteries)going to the kidneys or hormone

producing tumors can also be causes.For a more thorough explanation, click

here!

hypertrophy).

TreatmentHypertension is managed with a

combination of hygienic approaches

and medication. A low salt diet,exercise, weight loss when obesity ispresent, and stress reduction may all

help. Most individuals also requiremedication to maintain a blood

pressure lower than 140/90. If theblood pressure has caused cardiac

remodeling (see diagram) reducingblood pressure can encourage the heart

to return to its former shape andfunction.

Heart Failure and Your Neuroendocrine System

Paradoxically, activity of the neuroendocrine (body regulation) system, that

normally functions to maintain the circulation, can actually worsen heart failure ifsustained over time. By following the feedback control it is programmed to, it

inadvertently adds strain to the heart. Examine the scenario below where the bodyis entering the early stages of heart failure due to blocked heart arteries. Click here

to see a quick overview of the neuroendocrine system, if necessary.


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With time, the heart failure becomes worse and worse. High blood volumes and

remodeling increase heart size over time, which further impacts its ability toadequately eject blood. In this way, a system designed to support our heart has

caused it to fail when attempting to compensate for heart injury.

Why would the body do this to itself? Consider that the design of this system has

evolved in such a way as to protect our body not from heart damage, but fromexterior threats. For example, if one suffers an injury where blood is being lost

(see example), survival is dependent on maintaining an adequate blood pressure toall vital organs. If blood is lost, then blood pressure in our arteries will drop

accordingly. Fluid retention serves to keep high blood volumes to buffer the lossdue to injury. By constricting our arteries as shown before, the remaining blood

gets mobilized more efficiently to tissues at an adequate pressure. Therefore,possibly the situation shown in the chart isn't so much an error in design of the

neuroendocrine system so much as a misapplication of a control mechanisminitiated by initial heart and circulatory impairment.

Heart Failure and Your Heart

Once the heart has been injured, the body will attempt to compensate for reduced


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blood flow. Unfortunately, many of the countermeasures actually increase strainon the heart and further the development of heart failure.

The heart, after suffering damage or being placed under physical stress by high

blood pressure, will begin to change its own shape. This deforming of the

ventricles' shape is known as remodeling or hypertrophy. This remodeling occursin two primary patterns - concentric and dilated (as shown below):

Key

h = Thickness c = Concentricr = Radius n = Normal

d = Dilated

These diagrams represent cross-sections of the left ventricle, the chamber that

supplies the body with oxygenated blood flow. The triangular notches are cut into

each ventricle to demonstrate how the wall has changed in shape and thickness.

For comparative terms, the normal heart essentially looks like a football. When

the wall thickens in concentric circles (lower left), The heart works less effectivelyand takes on the shape of a large fist. This may be caused by hypertension, a

blocked aortic valve, or underlying genetics. Dilation of the ventricle walls (lowerright) gives the weakened heart a beach-ball shape and an inefficient contraction.

This prohibits blood from leaving the heart as it normally would. This remodelingpattern follows damage from a heart attack, sustained hypertension, viral

infection, or genetic causes.

Heart failure occurs when the heart can't pump blood to the body as quickly asneeded. Blood returning to the heart faster than the heart can eject it congests the


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system behind it. Decreased blood flow to organs, such as the kidneys, causes thebody to retain more fluid which complicates the problem further. The relationship

between the heart and other organs can be a delicate one - once one is injured, itcan send off a cascade of events that damage other organs and worsens heart

failure.

Medical Tests and Findings

Chest X-ray

Your doctor can use an x-ray to look at your heart, lungs, and blood vessels. He orshe can see if your heart is enlarged or if there is fluid around your lungs.

Pulmonary congestion shows up as cloudy areas on the x-ray. A chest x-rayrequires only a brief exposure to x-rays and is generally considered safe.

EchocardiogramThe echocardiogram is a procedure used to visualize the pumping action of the

heart. It is an ultrasound examination of the heart that can also measure blood flowinto and out of the heart.

ElectrocardiogramThis test also known as an "ECG" or"EKG", measures the electrical activity of

the heart. An electrocardiogram can check the heart's rhythm, evidence ofenlargement, and the presence of a prior or recent heart attack. Electrical wires

with adhesive ends are attached to the skin on your chest, arms, and legs. Theelectrical activity of the heart is then recorded on a piece of paper.

TracerStudies

Radioactive tracers given through a hand or arm IV are another tool used in thediagnosis of heart failure. Radioactivity is detected as the blood moves through the

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heart. In this way, doctors can outline the chambers of the heart, measure theejection fraction, and assess blood flow to regions of the heart muscle.

Treadmill Test

This test is known as a "stress test" because your heart's activity is being

monitored with an electrocardiogram during exercise. By walking on a treadmillfor specific intervals of time at differing intensity levels, your doctor can see ifyour symptoms are brought on by exertion and if they correlate with patterns on an

electrocardiogram.

Stress tests can be done using radioactive tracers such as thallium, Sesta MIBI, andMyoview. First, the tracer is injected into an IV tube in the arm before and during

exercise on the treadmill. After exercise, pictures of the heart can be taken to seewhere the tracer has been deposited, telling the doctor which areas are getting

enough blood and which are not.

Alternatively, stress testing can be done without exercise. The effects of stress onheart blood flow can be simulated through the use of an IV drug such as adenosineor persantine that dilates heart blood vessels, or dobutamine that increases heart

rate and function.

CatheterizationDoctors can insert a catheter, or small tube, into a leg (femoral) artery via a needle

stick and direct it to a region of the heart with x-ray guidance. Once in place, thecatheter can measure pressures in the heart and direct a dye used to visualize heart

chambers or blood vessels. This visualization technique is called angiography. Thex-rays show areas of narrowing or blockage. Catheters are also used to open

blocked heart arteries with angioplasty and stenting.

FROM MOSBY:

NURSING CARE OF CLIENTS WITH HEART FAILURE:

ASSESSMENT:

1. Baseline vital signs, breath sounds2. Daily weight; circumference of edematous extremities; abdominal girth3. Hemodynamic status (CVP, PAWP)4. Electrolytes levels ( sodium, chloride, potassium)5. Intake and output


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B. ANALYSIS/ NURSING DIAGNOSES:

1. Decreased cardiac output related to impaired cardiac function.2. Excess fluid volume related to impaired excretion of sodium and water.3. Impaired gas exchange related to excessive fluid in interstitial space.

C. PLANNING/ IMPLETATION:

1. Maintain the client in high- Fowlers position.2. Elevate extremities except when the client is in acute distress.3. Frequently monitor vital signs.4. Change position frequently.5. Monitor intake and output and daily weight.6. Restrict fluid as ordered.7. Monitor invasive lines.8. Refer to cardiac glycosides, antihypertensives, and diuretics for additional nursing actions.

D. EVALUATION/ OUTCOMES:

1. Maintains adequate tissue perfusion.2. Reduces peripheral edema/ ascites.3. Verbalizes understanding of pharmacologic and diet therapy.

Coronary computed tomography angiography (CTA) is a heart imaging test that helps determineif fatty or calcium deposits have narrowed a patients coronary arteries. Coronary CTA is a

special type of x-ray examination. Patients undergoing a coronary CTA scan receive an iodine-

containing contrast material as an intravenous (IV) injection to ensure the best possible images.

There are many things in life that will catch your eye, but only a few will catch your heart..pursue

those.

the heart is the only broken instrument that works


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Documents

Lecture 1-Heart Failure