Download Cardiovasular and Lymphatic Systems Unit 8

Cardiovascular and Lymphatic
Systems
Unit 8
Heather, Merissa and Tammy
Case Study 1
Mr. H has come to see you because his
brother has just had a ‘heart attack’ and
he wants to know if this is going to
happen to him
Question
Mr. H. says someone told him he could
have atherosclerosis and could have a
blood clot and die. He wants to know,
first, if this is true and second, if true,
what is atherosclerosis and what
happens to the heart to make a person
have a ‘heart attack’.
Atherosclerosis
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Occurs when the vessels of the heart thicken and harden as a
result of accumulation of lipid-laden macrophages within the
arterial wall which forms plague lesions (McCane & Huether,
2006)
It is the leading contributor to coronary artery and
cerebrovascular disease (McCane & Huether, 2006)
Atherosclerosis is a form of arteriosclerosis, and is an
inflammatory condition caused by the accumulation of lipid-laden
macrophages in the arterial walls (McCane & Huether, 2006)
Atherosclerosis is a progressive disease process that can be
described as follows: Low density lipoproteins (the bad
cholesterol) enter the vessel and are oxidized into
proinflammatory lipids. The oxidized LDL adheres to the vessel
wall allowing monocytes and T lymphocytes to cross into the
epithelium. Monocytes differentiate into macrophages that
consume the LDL, transforming into foam cells. These foam
cells then release cytokines that encourage atherosclerosis
(McCance & Huether, 2006).
Atherosclerosis
Atherosclerosis is a process that occurs in several phases:
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Damaged endothelium – Platelets attach to an injured
site
Fatty Streak – Platelets attach to endothelium
Fibrous Plague – Lipids pool and form a fissure in plague
Complicated Lesion – A thrombus forms
McCane & Huether, 2006
Link to Animation of
Atherosclerosis
Below is a link to a video on atherosclerosis
that discusses and demonstrates the
phases of the disease
http://www.youtube.com/watch?v=fLonh7Z
esKs
Answer
Yes, Mr. H could have atherosclerosis.
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He requires a detailed health history, physical examine and
blood work to determine his risk factors for the disease.
Family history is a strong predictor of atherosclerosis and
coronary artery disease (CAD). It would also be important to ask
Mr. H about other risk factors for atherosclerosis including his
age, the last time his lipids were checked and the results,
whether or not he smokes, his level of physical activity, obesity,
diet, and whether he was been screened for diabetes (McCance
& Huether, 2006; National Heart, Lung, and Blood Institute,
2007; The Heart and Stroke Foundation of Canada, 2007).
Pathophysiology of a “Heart
Attack”
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As a result of atherosclerosis many plagues that
form in the arteries are ‘unstable’ and rupture
When these plaques rupture, platelet adhesion
and thrombus formation results, causing
complete vessel obstruction and cardiac
ischemia and infarction (American Heart
Association, 2009; McCance & Huether, 2006).
The thrombus may occlude the vessel resulting
in ischemia and infarction (McCane & Huether,
2006)
What happens to the Heart
during a “Heart Attack”
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During a ‘heart attack’ or MI (myocardial infarction) blood flow is
occluded in the coronary arteries, causing hypoxia and ischemia
(McCane & Huether, 2006)
Cardiac cells begin to die, and after 30-60 seconds of hypoxia
ECG changes are noted (McCane & Huether, 2006)
The coronary artery primarily affected in an MI describes the
region of an MI in the heart. These include anterior, inferior,
posterior or lateral (McCane & Huether, 2006)
These locations also determine the type of treatment required in
an MI
Mr. H. returns for a follow up visit after having the
“tests” you advised. You review the results with
him. The only abnormality to date is ECG
evidence of left ventricular hypertrophy (LVH).
You are not surprised, as last visit you checked
Mr. H.’s blood pressure and it was 180/100.
When you take his BP at this visit, it is the
same. You tell him this and he shrugs and tells
you it has been high for a while. About a year
ago he was started on “BP med” but hadn’t felt
unwell and felt no different when he was taking
it so he stopped taking it.
Hypertension
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Hypertension is caused by any factors that increase cardiac
output or total peripheral resistance, or a combination of the two
(Breen, 2008; Mayoclinic.com, 2008; McCance & Huether, 2006)
Increased cardiac output is caused by increased heart rate and
stroke volume whereas increased resistance is caused by
increased blood viscosity or decreased blood vessel diameter
Primary (or essential) hypertension can be caused by genetic
predisposition, specifically genetic factors influencing renal
sodium excretion, insulin sensitivity, activity of the reninangiotensin-aldosterone system, cell membrane sodium and
calcium transport, and the systemic response to neurogenic
hormones (Breen, 2006; McCance & Huether, 2006).
Secondary hypertension results from altered hemodynamics due
to a primary disease, such as renal dysfunction or congenital
heart defects (Mayoclinic.com, 2008; McCance & Huether,
2006).
Causes of Hypertension
There are several causes of hypertension, some modifiable
and others that can not be changed. Causes include:
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family history
Age (45 and over for men and 55 and over for
women)
Ethnicity
Gender
smoking
being overweight
being physically inactive
excessive alcohol consumption
diet
Diabetes
High Cholesterol
Stress
Renal Disease
high sodium intake
Ministry of Health, 2009
Mr. H.
You discuss with Mr. H. the damage to his
heart. You want to impress upon him the
other end organ damage that occurs with
untreated hypertension.
Clinical Signs and Symptoms
of Untreated Hypertension
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Hypertension is diagnosed when the systolic BP is greater
than 140, or the diastolic BP is greater than 90 on with two
different blood pressure readings on different occasions
(McCance & Huether, 2006).
Sustained uncontrolled hypertension can lead to cardiac
disease, renal insufficiency, transient ischemic attacks,
strokes, and retinopathy, among others (Breen, 2008;
McCance & Huether, 2006)
If symptoms of hypertension are present, they may
include headaches, dizzy spells, and nose bleeds
(Mayoclinic.com, 2008)
Clinical Signs and Symptoms
of Untreated Hypertension
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Enlarged heart. High blood pressure puts extra demand on the heart. Over time,
the heart grows bigger to compensate for the extra work and, ultimately,weakens.
Kidney damage. Over time, uncontrolled high blood pressure can cause
narrowing of the arteries supplying the kidneys. High blood pressure also damages
the kidneys directly and may lead to kidney failure. Kidney damage, in turn, raises
blood pressure even more.
Stroke. High blood pressure can cause narrowing of the arteries that supply the
brain. If a blood clot forms and block a vessel, the subsequent lack of oxygen to
the brain can cause a stroke. High blood pressure can also cause arteries in the
brain to burst. The resulting bleeding into the brain produces a different kind of
stroke.
Heart attack. The coronary arteries carry blood that delivers oxygen to the heart.
If these vessels become blocked, a heart attack can occur (National Institute of
Health, 2003)
Hypertensive Retinopathy: In untreated hypertension, the small vessels in the
eyes become damaged, causing thickening, bulging and leakage (Wikipedia.com,
2009). Signs and symptoms would include headache and visual disturbances.
Hypertensive (valvular) cardiomyopathy: Occurs because of the continual
increased resistance to ventricular ejection seen in HTN. Diastolic and Systolic
dysfunction eventually occur (McCance & Huether, 2006). Signs and symptoms
would coincide with the severity of heart failure (and if left, right or both).
References
American Heart Association (2009). Atherosclerosis. Retrieved February 22, 2009 from
http://www.americanheart.org/presenter.jhtml?identifier=4440
Breen, J. (2008). An introduction to causes, detection, and management of hypertension. Nursing
Standard, 23 (14), 42-46. Retrieved February 22, 2009 from ProQuest Nursing & Allied Health
Source database.
Mayoclinic.com (2008). High blood pressure (Hypertension). Retrieved February 22, 2009 from
http://www.mayoclinic.com/health/high-blood-pressure/DS00100/DSECTION=causes
McCane, K. & Huether, S. (2006). Pathophysiology: The biologic basis for disease in adults and
children. (5th ed.). St. Louis, MI: Elsevier Mosby.
Ministry of Health. (2009). Chronic Disease Management. Retrieved February 21, 2009 from:
http://www.health.gov.bc.ca/cdm/patients/hyperten/index.html#causes
National Heart, Lung, and Blood Institute (2007). What is atherosclerosis? Retrieved February 22,
2009 from
http://www.nhlbi.nih.gov/health/dci/Diseases/Atherosclerosis/Atherosclerosis_WhatIs.html
References
National Institute of Health. (2003). Complications of Untreated Hypertension.
Retrieved February 22, 2009 from:
http://www.healthatoz.com/healthatoz/Atoz/common/standard/transform.jsp?requ
estURI=/healthatoz/Atoz/dc/caz/card/hypr/hypercomp.jsp
The Heart and Stroke Foundation of Canada (2007). Atherosclerosis. Retrieved
February 22, 2009 from
http://www.heartandstroke.com/site/c.ikIQLcMWJtE/b.3484059/k.9F8E/Atherosclerosis.
htm
The Heart and Stroke Foundation of Canada (2007). Heart disease prevention.
Retrieved February 22, 2009 from
http://www.heartandstroke.com/site/c.ikIQLcMWJtE/b.3483919/k.78DE/Prevention_
of_Risk_Factors.htm
Wikipedia.com. ( 2009). Hypertension. Retrieved February 22, 2009, from
http://en.wikipedia.org/wiki/Hypertensive_retinopathy