Pathophysiology of cardiovascular bPresentation Transcript
PATHOPHYSIOLOGY OFPATHOPHYSIOLOGY OF
Med PrepMed Prep
J.J. Nelson RN,CMAJ.J. Nelson RN,CMA
Ventricular Septal DefectVentricular Septal Defect
• Septal defects are sometimes called a "hole" in theSeptal defects are sometimes called a "hole" in the
• A defect between the heart's two the ventricles is calledA defect between the heart's two the ventricles is called
a ventricular septal defect (VSD).a ventricular septal defect (VSD).
• When there is a large opening between the ventricles, aWhen there is a large opening between the ventricles, a
large amount of oxygen-rich (red) blood from thelarge amount of oxygen-rich (red) blood from the
heart's left side is forced through the defect into theheart's left side is forced through the defect into the
right side.right side.
• Ventricular septal defects are among the most commonVentricular septal defects are among the most common
congenital heart defects, occurring in 0.1 to 0.4 percentcongenital heart defects, occurring in 0.1 to 0.4 percent
of all live births and making up about 20 to 30 percentof all live births and making up about 20 to 30 percent
of congenital heart lesions.of congenital heart lesions.
Atrial Septal DefectAtrial Septal Defect
•When an atrial septal defect is present, blood flows
through the hole primarily from the left atrium to
the right atrium.
•This shunting increases the blood volume in the
right atrium which means more blood flows through
the lungs than would normally.
•If left untreated, atrial septal defect may cause
problems in adulthood.
What is cyanosis?What is cyanosis?
Coarctation of the AortaCoarctation of the Aorta
• Coarctation of the aorta — or aortic coarctationCoarctation of the aorta — or aortic coarctation
— is a narrowing of the aorta. When this— is a narrowing of the aorta. When this
vascular defect occurs, the heart must pumpvascular defect occurs, the heart must pump
harder to force blood through the constrictedharder to force blood through the constricted
segment of your aorta.segment of your aorta.
• Coarctation of the aorta is a condition that'sCoarctation of the aorta is a condition that's
generally present at birth (congenital). It'sgenerally present at birth (congenital). It's
relatively common, accounting for 5 percent to 10relatively common, accounting for 5 percent to 10
percent of all congenital heart conditions.percent of all congenital heart conditions.
• Coarctation of the aorta may range from mild toCoarctation of the aorta may range from mild to
severe. It usually requires surgical treatment andsevere. It usually requires surgical treatment and
requires careful follow-up through infancy andrequires careful follow-up through infancy and
into adulthood.into adulthood.
Coarctation of the AortaCoarctation of the Aorta
• Pericarditis occurs when the pericardium,Pericarditis occurs when the pericardium,
becomes inflamed (damaged from infection orbecomes inflamed (damaged from infection or
• Fluid from the inflammation can increase pressureFluid from the inflammation can increase pressure
on the heart, squeezing it and making it harder toon the heart, squeezing it and making it harder to
pump blood to the body.pump blood to the body.
• Pericarditis often causes chest pain and sometimesPericarditis often causes chest pain and sometimes
other symptoms. Pericarditis may be acute orother symptoms. Pericarditis may be acute or
chronic. The sharp chest pain associated with acutechronic. The sharp chest pain associated with acute
pericarditis occurs when the pericardium rubspericarditis occurs when the pericardium rubs
against the heart's outer layer.against the heart's outer layer.
Note the excessive pericardial fluid.
Rheumatic FeverRheumatic Fever
• Rheumatic Fever is an inflammatory disease,Rheumatic Fever is an inflammatory disease,
which occurs as a delayed sequel towhich occurs as a delayed sequel to
pharyngeal infection with streptococcalpharyngeal infection with streptococcal
bacteria. It involves principally the heart,bacteria. It involves principally the heart,
joints, central nervous system and skin.joints, central nervous system and skin.
• Symptoms of rheumatic fever generallySymptoms of rheumatic fever generally
appear within five weeks after an untreatedappear within five weeks after an untreated
streptococcal (strep) throat infection.streptococcal (strep) throat infection.
• There's no cure for rheumatic fever. But it canThere's no cure for rheumatic fever. But it can
be prevented by prompt and thoroughbe prevented by prompt and thorough
treatment of a strep throat infection withtreatment of a strep throat infection with
Rheumatic Heart DiseaseRheumatic Heart Disease
• In more than half of all cases, rheumatic feverIn more than half of all cases, rheumatic fever
scars the valves of the heart (rheumatic heartscars the valves of the heart (rheumatic heart
disease) forcing this vital organ to workdisease) forcing this vital organ to work
harder to pump blood.harder to pump blood.
• In rare cases the inflammation causes soIn rare cases the inflammation causes so
much damage to the heart muscle that it leadsmuch damage to the heart muscle that it leads
to heart failure.to heart failure.
• In other cases, a scarred heart valve mayIn other cases, a scarred heart valve may
require surgery to repair or replace therequire surgery to repair or replace the
damaged valve or valves.damaged valve or valves.
Valvular Heart DiseaseValvular Heart Disease
• Valvular heart disease occurs when the heart's valvesValvular heart disease occurs when the heart's valves
do not work correctly. Valvular heart disease can bedo not work correctly. Valvular heart disease can be
caused bycaused by valvular stenosisvalvular stenosis oror valvular insufficiencyvalvular insufficiency..
• InIn valvular stenosisvalvular stenosis,, the tissues forming the valvethe tissues forming the valve
leaflets become stiffer, narrowing the valve openingleaflets become stiffer, narrowing the valve opening
and reducing the amount of blood that can flowand reducing the amount of blood that can flow
through it.through it.
• If the narrowing is mild, the overall functioning of theIf the narrowing is mild, the overall functioning of the
heart may not be reduced. However, the valve canheart may not be reduced. However, the valve can
become so narrow (stenotic) that heart function isbecome so narrow (stenotic) that heart function is
reduced, and the rest of the body may not receivereduced, and the rest of the body may not receive
adequate blood flow.adequate blood flow.
Valvular StenosisValvular Stenosis
• A narrowed orA narrowed or
“stenotic” valve“stenotic” valve
requires the heart torequires the heart to
pump harder,pump harder,
which can strain thewhich can strain the
heart and reduceheart and reduce
blood flow to theblood flow to the
Valvular InsufficiencyValvular Insufficiency
• Another valvular heartAnother valvular heart
disease condition,disease condition,
incompetence, "leakyincompetence, "leaky
valve"), occurs whenvalve"), occurs when
the leaflets do not closethe leaflets do not close
completely, lettingcompletely, letting
blood leak backwardblood leak backward
across the valve.across the valve.
Valvular Heart DiseaseValvular Heart Disease
• Valvular disease is acquired orValvular disease is acquired or
congenital and can involve any of thecongenital and can involve any of the
four heart valves.four heart valves.
• Heart murmurs are most often causedHeart murmurs are most often caused
by defective heart valves. Valvularby defective heart valves. Valvular
stenosis and insufficiency may be heardstenosis and insufficiency may be heard
as a heart murmuras a heart murmur
• The Auscultation Assistant - Hear HeartThe Auscultation Assistant - Hear Heart
Murmurs, Heart Sounds, and Breath SoundsMurmurs, Heart Sounds, and Breath Sounds
Hypertension (HTN)Hypertension (HTN)
• HTN is defined as a BP over 140/90 mm/HgHTN is defined as a BP over 140/90 mm/Hg
• Most often the disease is idiopathic andMost often the disease is idiopathic and
asymptomatic (occasional epistaxis or vertigo).asymptomatic (occasional epistaxis or vertigo).
• In 90 percent to 95 percent of high bloodIn 90 percent to 95 percent of high blood
pressure cases, the American Heartpressure cases, the American Heart
Association says there's no identifiable cause.Association says there's no identifiable cause.
This type of high blood pressure, calledThis type of high blood pressure, called
essential hypertensionessential hypertension oror primaryprimary
hypertensionhypertension, tends to develop gradually over, tends to develop gradually over
many years.many years.
HTN: “Silent Killer”HTN: “Silent Killer”
• The other 5The other 5
percent to 10percent to 10
percent of highpercent of high
blood pressureblood pressure
cases are causedcases are caused
by an underlyingby an underlying
condition. Thiscondition. This
type of hightype of high
blood pressure,blood pressure,
Coronary Artery DiseaseCoronary Artery Disease
• Coronary artery diseaseCoronary artery disease
(CAD) is the most(CAD) is the most
common type of heartcommon type of heart
disease. It is the leadingdisease. It is the leading
cause of death in thecause of death in the
United States in bothUnited States in both
men and women.men and women.
• Cholesterol builds up in the coronary arteries causing
hardening and narrowing. Without adequate oxygen the
heart muscle sends messages via angina pectoris or a heart
attack (myocardial infarction)
Myocardial InfarctionMyocardial Infarction
• The termThe term infarctioninfarction describes necrosis or deathdescribes necrosis or death
of myocardial cells. Atherosclerotic heartof myocardial cells. Atherosclerotic heart
disease is the most common underlying causedisease is the most common underlying cause
of myocardial infarction.of myocardial infarction.
• During acute myocardial infarction, theDuring acute myocardial infarction, the
central area of necrosis is generallycentral area of necrosis is generally
surrounded by an area of injury, which insurrounded by an area of injury, which in
turn is surrounded by an area of ischemia.turn is surrounded by an area of ischemia.
Thus, various stages of myocardial damageThus, various stages of myocardial damage
can coexist. The distinction between ischemiacan coexist. The distinction between ischemia
and necrosis is whether the phenomenon isand necrosis is whether the phenomenon is
MIMI• Blockage may beBlockage may be
caused by spasm of thecaused by spasm of the
artery or byartery or by
atherosclerosis withatherosclerosis with
acute clot formation.acute clot formation.
• The area affected (sizeThe area affected (size
and location) alongand location) along
with the patientswith the patients
health status plays anhealth status plays an
important part in theimportant part in the
Congestive Heart FailureCongestive Heart Failure
• Congestive heart failure (CHF), or heart failure,Congestive heart failure (CHF), or heart failure,
is a condition in which the heart can't pumpis a condition in which the heart can't pump
enough blood to the body's other organs.enough blood to the body's other organs.
• The "failing" heart keeps working but not asThe "failing" heart keeps working but not as
efficiently as it should. People with heartefficiently as it should. People with heart
failure can't exert themselves because theyfailure can't exert themselves because they
become short of breath and tired.become short of breath and tired.
• As blood flow out of the heart slows, bloodAs blood flow out of the heart slows, blood
returning to the heart through the veins backsreturning to the heart through the veins backs
up, causing congestion in the tissues. Thisup, causing congestion in the tissues. This
results in edema and dyspnea.results in edema and dyspnea.
NORMAL HEART HEART WITH CHF
Heart disease may be congenital, or acquired fromHeart disease may be congenital, or acquired from
our life style. Health care workers must educateour life style. Health care workers must educate
the patient to prevent disease and recognize thethe patient to prevent disease and recognize the
symptoms of disease.symptoms of disease.