Download Chapter_047

Assisting in Cardiology
Chapter 47
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
1
Learning Objectives





Define, spell, and pronounce the terms listed
in the vocabulary.
Apply critical thinking skills in performing
patient assessment and care.
Illustrate the anatomy and physiology of the
heart and its significant structures.
Summarize risk factors for the development of
cardiovascular disease.
Describe the signs, symptoms, and medical
procedures employed in the diagnosis and
treatment of coronary artery disease and
myocardial infarction.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
2
Learning Objectives




Compare and contrast the treatment
protocols for hypertension.
Outline the causes and results of congestive
heart failure.
Illustrate the effects of inflammation and
valvular disorders on cardiac function.
Describe the anatomy and physiology of the
vascular system.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
3
Learning Objectives



Differentiate among the various types of
shock.
Summarize the characteristics of common
vascular disorders.
Outline typical cardiovascular diagnostic
procedures.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
4
Location of Heart in Thoracic Cavity
From Applegate EJ: The anatomy and physiology learning system, ed 3, St Louis, 2006, Saunders.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
5
Anatomy of the Heart


The heart is a muscular organ that pumps blood
through the body, circulating a continuous supply
of oxygen and nutrients to the cells and picking
up the metabolic waste products.
The three layers of tissue are surrounded by a
double-membrane sac called the pericardium;
the epicardium is the first layer of the heart; the
middle muscular layer of the heart is the
myocardium; and the inner layer, the
endocardium, forms the heart valves.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
6
Layers of the Heart
From Damjanov IL: Pathology for the health-related professions, ed 3, Philadelphia, 2006, Saunders.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
7
Blood Flow



Blood flow through the heart begins in the right
atrium, which receives deoxygenated blood
from the inferior and superior vena cava.
The right atrium contracts, and blood passes
through the tricuspid valve into the right
ventricle.
The right ventricle contracts, and blood passes
from the right ventricle to the lungs via the
pulmonary artery (the only artery in the body
that carries deoxygenated blood).
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
8
Blood Flow



Oxygenation occurs in the lungs, and the blood
returns to the left atrium through the pulmonary
veins (the only veins in the body that carry
oxygen-rich blood).
The left atrium contracts, and blood passes
through the mitral (bicuspid) valve into the left
ventricle.
The left ventricle contracts, and oxygen-rich
blood is sent out to the body through the aorta
(the largest artery in the body).
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
9
Chambers of the Heart
From Damjanov IL: Pathology for the health-related professions, ed 3, Philadelphia, 2006, Saunders.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
10
Coronary Arteries
From Frazier MS, Drzymkowski JW: Essentials of human disease and conditions, ed 4, St Louis, 2009, Saunders.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
11
Heart Conduction




Originates in the SA node (the pacemaker of the
heart) located in the posterior, superior wall of the
right atrium.
Electrical charge crosses both atria, which contract
and pass blood into the ventricles.
Electrical charge collects in the AV node, located
on the septal wall between the right atria and
ventricles.
After a slight pause, the AV node releases the
charge, sending it through the bundle of His,
located in the septum between the two ventricles.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
12
Cardiac Conduction System
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
13
Heart Conduction






The bundle of His divides into the left and right bundle
branches, which surround the left and right ventricles.
Electrical charge continues through the Purkinje fibers,
the most distal part of the heart’s conduction system.
The Purkinje fibers complete ventricular stimulation,
and the ventricles contract.
Contraction of the heart chambers is depolarization.
After contraction, repolarization or electrical recovery
occurs.
Polarization is the heart at rest.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
14
Diseases and Disorders of the Heart

Multiple risk factors for cardiac disease include:

genetic predisposition and family history
 hypertension
 age
 gender
 diabetes
 elevated blood cholesterol levels
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
15
Cardiac Disease Risk Factors

Lifestyle factors include:

High-fat, high-caloric diets
 Obesity
 Smoking
 Lack of exercise
 Hypertension
 Stress
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
16
Heart Disease Risk in Women
Women are at greater risk with the following factors:
 Metabolic syndrome
 combination of hypertension, elevated insulin levels, excess
body fat around the waist, and high blood cholesterol levels
 Increased levels of stress and/or depression
 Female smokers are at much greater risk than male smokers
 Decreased estrogen production before menopause
 Difference in female risks and symptoms is associated with
the method of plaque buildup in women
 develop an evenly spread layer of plaque along the entire
lumen of blood vessels rather than localized plaque buildup
 have diffuse atheroma buildup in smaller vessels, which
causes more subtle symptoms
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
17
Coronary Artery Disease



Arteries supplying the myocardium become
narrowed by atherosclerotic plaques.
Platelets stick to the plaque deposits, forming
thrombi, and lipids continue to build up at
the site.
The process causes narrowing of the lumen of
the arteries and inhibits normal blood flow,
depriving the myocardium of adequate blood.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
18
Coronary Artery Disease
From Gould BA:
Pathophysiology for the
health professions, ed 3,
Philadelphia, 2002,
Saunders.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
19
Coronary Artery Disease

Myocardial ischemia signs and symptoms:
angina pectoris (pain behind the sternum that
can be relieved by rest or nitroglycerin)
followed by pressure or fullness in the chest,
syncope, edema, unexplained coughing spells,
and fatigue.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
20
Myocardial Infarction



Symptoms of myocardial infarction (MI) are
very similar to those of angina, but myocardial
infarction pain lasts longer than 30 minutes and
is unrelieved by rest or nitroglycerin tablets.
An MI is diagnosed by ECG changes and
elevated cardiac enzymes 6 to 12 hours after
the episode.
Enzymes are released by the necrotic
myocardium and continue to increase for 24 to
49 hours after the MI.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
21
Myocardial Infarction Symptoms in
Women


Ischemia over a prolonged period leads to
necrosis of a portion of the myocardium,
resulting in a myocardial infarction.
Women may exhibit a different clinical picture
from that in men.

Abdominal or midback pain
 Jaw pain
 Indigestion
 Extreme fatigue
 Aching in both arms
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
22
Critical Thinking Application

A patient who is scheduled for an
appointment in 2 days calls the office and
reports that she is not feeling well. She
complains that she has a feeling of fullness in
the chest, her arms ache, and she is very
tired. Although this patient does not have a
history of myocardial infarction, what should
Adam do?
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
23
Telephone Screening for Chest Pain

Activate EMS if:

Chest pain is crushing and radiating
 Diaphoresis, dyspnea, nausea, indigestions, vertigo
 History of CAD, MI, or angina
 Change in pattern of angina
 Chest pain occurs at rest or with minimal exertion
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
24
MI Diagnosis


ECG changes and elevated cardiac enzymes
Blood tests


Creatinine kinase (CK) levels – start increasing
6 hours after initial MI and reach a peak in 18 hours
with a return to normal in 24 to 36 hours; the more
severe the cardiac damage the longer it takes for
CK levels to peak and return to normal
Troponin levels – can detect minor myocardial
damage not evident with CK levels; levels increase
4–6 hours after initial MI and peak in 10 to 24 hours;
with minor myocardial damage, levels are elevated
up to 10 to 14 days
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
25
MI Treatment






Thrombolytic medications (Activase, Retavase)
to dissolve the coronary artery blockage, but
must be started within 12 hours of initial
symptoms
Aspirin
Beta-blockers (Tenormin, Lopressor, Inderal)
Anticoagulants (Coumadin)
Anticholesterol agents (Lipitor, Zocor, Mevacor)
Percutaneous transluminal coronary angioplasty
or open-heart surgery may be indicated
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
26
Hypertensive Heart Disease




Secondary hypertension occurs because of a
disease process in another body system.
Primary hypertension is idiopathic.
MA responsibility—two BP readings, 2 minutes
apart, with patient sitting in chair; if elevated,
check BP in the other arm.
Chronic elevated blood pressure can result in
left ventricular hypertrophy, angina, MI, heart
failure, stroke, or nephropathy.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
27
Classification of Blood Pressure







Normal BP: SBP <120 and DBP <80
Prehypertension: 120–139 or 80–89
Hypertension stage 1: 140–159 or 90–99
Hypertension stage 2: ≥160 or ≥100
Hypertension treatment: treat BP <140–90 mm Hg
or <130/80 in patients with diabetes or chronic
kidney disease
Most patients require two medications to reach BP
goal (diuretic and hypertensive medication)
Refer to Table 47-2 for hypertensive medications
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
28
Lifestyle Modifications





Weight reduction: BMI from 19 to 25 will lower
SBP 5–20 mm Hg/10 kg
DASH diet (rich in fruit and vegetables, low-fat
dairy products, reduce saturated and total fat):
SBP reduction of 8–14 mm Hg
Decrease sodium (2.4 g/day): SBP drops
2–8 mm Hg
Aerobic exercise (30 min/day): drops 4–9 mm Hg
Moderate alcohol intake (men, no more than two
drinks/day; women, one): drops 2–4 mm Hg
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
29
Risk Factors

Risk factors for developing hypertension
include:

family history of hypertension or stroke
 hypercholesterolemia
 smoking
 high sodium intake
 diabetes
 excessive alcohol intake
 aging
 prolonged stress
 race
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
30
Critical Thinking Application

Essential hypertension is a common problem
for patients seen in the cardiology department
where Adam works. What could Adam do to
help patients with primary hypertension?
What informational materials or community
resources would be helpful in gaining patient
compliance with treatment?
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
31
Congestive Heart Failure


Congestive heart failure occurs when the
myocardium is unable to pump enough blood
to meet the needs of the body.
Develops over time because of weakness in
the left ventricle from chronic hypertension or
MI of the ventricular wall; valvular heart
disease; or pulmonary complications.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
32
Heart Failure


Typically, heart failure initially occurs on one
side of the heart followed by the other side.
Treatment:






Limiting physical activity
Sodium restriction
Weight control
Diuretics
ACE inhibitors and digoxin
Routine monitoring of serum electrolytes to monitor
potassium levels
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
33
Left-Sided Heart Failure



Left-sided heart failure is usually caused by
essential hypertension or left ventricle disease.
Causes a backup of blood in the lungs,
resulting in pulmonary edema.
Signs and symptoms

Dyspnea
 Orthopnea
 Nonproductive cough
 Rales
 Tachycardia
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
34
Right-Sided Heart Failure




Right-sided heart failure causes a backup of blood
in the right atrium, which prevents complete
emptying of the vena cava, resulting in systemic
edema, especially in the legs and feet.
Right-sided heart failure can develop from lung
disease.
Cor pulmonale—right-sided heart failure caused by
pulmonary hypertension resulting from COPD.
Both types of heart failure cause fatigue,
weakness, exercise intolerance, dyspnea, and
sensitivity to cold temperatures.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
35
Treatment for CHF



Nonmedication treatment – limit physical
activity, restrict salt, no smoking, reduce
stress, and control weight
Patient education – stress monitoring weight
gain; sudden increase in weight may indicate
fluid retention
Drug therapy – diuretics; ACE inhibitor
(Vasotec, Prinivil, Zestril, Capoten); Digoxin;
beta-blockers (Coreg, Lopressor); potassium
supplement.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
36
Critical Thinking Application

Kate Glasgow, a 76-year-old patient with a
history of CHF, is in the office today for a
checkup. Miss Glasgow does not understand
why she needs to stop using salt and does
not weigh herself regularly at home. What
can Adam do to help this patient understand
the importance of her treatment regimen?
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
37
Hypotension




Orthostatic or postural hypotension.
Common problem in elderly.
May contribute to falls and related injuries.
Patients need to be evaluated for secondary
causes and encouraged to adjust from a prone
position by sitting at the side of the bed before
standing.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
38
Rheumatic Heart Disease




Develops because of unusual immune reaction that
occurs approximately 2 weeks after an untreated
beta-hemolytic streptococcal infection
Antibodies cause inflammation in the layers of the
heart
Pericarditis—decreases cardiac activity and causes
pericardial effusion
Endocarditis—most common heart complication

Vegetations form along the outer edges of the valve
cusps, causing scarring and stenosis
 Treatment: penicillin and antiinflammatory agents;
prophylactic antibiotics before all invasive procedures
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
39
Valvular Disorders



Disorders of the valves of the heart may be caused
by a congenital defect or an infection, such as
endocarditis or rheumatic heart disease. Two
specific problems can occur with valve disease.
The valve can be stenosed, restricting the forward
flow of blood, or it can be incompetent, so blood can
leak backward.
The most common valve defect is mitral valve
prolapse (MVP), an incompetence caused by a
congenital defect or vegetation and scarring from
endocarditis.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
40
Arteries and Veins

Blood vessels are divided into two systems that
begin and end with the heart.



Arteries carry oxygenated blood away from the
heart.
Capillaries are microscopic vessels responsible for
the exchange of oxygen and carbon dioxide in the
tissue.
Veins carry deoxygenated blood back to the heart.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
41
Blood Vessels
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
42
Shock




Shock—general collapse of the circulatory system;
includes decreased cardiac output, hypotension, and
hypoxemia.
Initial signs—extreme thirstiness, restlessness, and
irritability.
Body attempts to compensate with vasoconstriction of
peripheral blood vessels, causing cool, clammy skin;
pallor; tachycardia; and decreased urinary output.
Signs and symptoms progress to a rapid, weak, and
thready pulse; tachypnea; altered levels of
consciousness. If the process is not reversed, the CNS
becomes depressed and acute renal failure may occur.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
43
Types of Shock





Cardiogenic—MI, pulmonary embolism, CHF
Hypovolemic—hemorrhage, burns
Neurogenic—spinal cord injury, stress, drug
reaction
Anaphylactic—allergic reaction
Septic—systemic infection
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
44
Varicose Veins




Varicose veins are dilated, tortuous, superficial veins that
develop because the valves do not completely close,
allowing blood to flow backward.
Causes the vein to distend from the increased pressure.
Caused by congenitally defective valves, pregnancy,
obesity, prolonged standing or sitting, heavy lifting.
Treatment:





Aerobic exercise
Limit heavy lifting
Elevate legs when possible
Wear support stockings
Possible surgical intervention
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
45
Varicose Veins
From Damjanov
IL: Pathology for
the health-related
professions, ed 3,
Philadelphia,
2006, Saunders.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
46
Deep Vein Thrombosis






DVT—thrombus with inflammatory changes that has
attached to the deep venous system of the lower legs
Causes partial or complete obstruction of vessel
Symptoms—50% asymptomatic at first; calf pain;
swelling, warmth, edema, erythema at site
Embolus—thrombus becomes dislodged and begins to
circulate through the general circulation; pulmonary
embolism is most serious
Diagnosis: Doppler—measures rate of RBC flow;
venography
Treatment: IV heparin, oral coumadin; bed rest
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
47
Prevention of Deep Vein Thrombosis





Take prescribed medications as directed.
If prescribed anticoagulants, foods high in vitamin
K (dark green leafy vegetables, canola and soy
oils) should be eaten in small amounts.
Avoid sitting still for long periods of time;
periodically walk around or move legs frequently.
Alter lifestyle factors such as obesity, smoking,
and hypertension since they increase DVT risk.
Wear compression stockings as ordered by the
physician.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
48
Critical Thinking Application

Alitza Lincoln is a 43-year-old patient who has
large varicose veins in both legs and a history of
phlebitis. She is a checkout clerk at the local
Wal-Mart, so she stands for extended periods of
time. The physician is concerned about the
development of a DVT and instructs Ms. Lincoln
on the prevention, signs, and symptoms of a
thrombus. Alitza asks Adam what she can do to
prevent further problems with the veins in her legs.
Adam uses a picture to illustrate the valves in the
leg veins and explains preventive measures. What
measures should Adam include?
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
49
Arterial Disorders


Arteriosclerosis—thickening and loss of
elasticity of arterial walls associated with aging;
can occur in arteries throughout the body and
cause systemic ischemia and necrosis
Atherosclerosis (form of arteriosclerosis)—
formation of an atheroma (a buildup of
cholesterol, cellular debris, and platelets along
the inside vessel wall)
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
50
Treatment for Hypercholesterolemia






Diet – reduce saturated fats and foods high in
cholesterol
Aerobic exercise to elevate HDL levels
Stop smoking
Statin drugs – Lipitor and Zocor
Patient education about risk factors and
promoting alterations in lifestyle
Referral to dietitian
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
51
Atherosclerotic Plaque
From Damjanov IL: Pathology for the health-related professions, ed 3, Philadelphia, 2006, Saunders.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
52
Vessel Disorders

Aneurysm—dilation of vessel wall
Caused by Marfan’s syndrome; atherosclerosis
 Diagnosis: bruit; arteriograms; sonography; CT scan
 Treatment: surgical repair

Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
53
Vessel Disorders
From Damjanov IL:
Pathology for the healthrelated professions, ed 3,
Philadelphia, 2006,
Saunders.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
54
Peripheral Artery Disease




Due to widespread atherosclerotic plaque buildup
in the arteries outside of the heart, especially in the
legs
Plaque deposits decrease the lumen size and
amount of oxygenated blood delivered to tissues
Symptoms – intermittent claudications; leg
numbness or weakness; persistently cold
extremities; sores of the feet or legs that do not
heal; and hair loss on the extremities
Most effective treatments – regular exercise to
promote new vessel growth and smoking cessation
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
55
Diagnostic Procedures

Cardiovascular diagnostic procedures include:

Doppler studies of the patency of blood vessels
 Angiography to visualize arterial pathways
 Echocardiography to assess the structure and
movement of the parts of the heart, especially the
valves
 Cardiac catheterization to visualize the heart
chambers, valves, and coronary arteries; may be
followed with angioplasty and placement of stent
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
56
Cardiac Treatment Procedures


Pacemaker – small battery-powered device
implanted in the chest wall to generate an electrical
impulse that is sent to the heart along flexible lead
wires; can monitor BP, temperature, and breathing
rate to determine whether the heart needs to be
stimulated to contract more frequently; must be
replaced when battery pack wears out
Implantable cardioverter-defibrillator (ICD) –
pager-size device implanted in the chest under the
skin and attached to the heart with small wires;
continuously monitors heart rhythm and delivers
electric shock to correct life-threatening
arrhythmias
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
57
Patient Education



The medical assistant can help patients by
encouraging and supporting them by using
community resources.
Patients learn best through visuals aids.
Document educational interventions.
Copyright © 2011, 2007, 2003, 1999 by Saunders, an imprint of Elsevier Inc. All rights reserved.
58