heart disease
pump failed- systolic and diastolic dysfunction
obstructed flow-systemic HTN, calcified aortic stenosis, aortic coarctation
regurgitation-causes increase volume workload
shunted flow- causes volume and pressure overload
cardiac conduction disorders-uncoordinated cardiac impulses, blocked cardiac conduction pathway, arrhythmias
heart n major blood vessels ruptured-causes huge blood loss, hypotension, shock, fatal
systolic dysfunction
heart cannot empty properly
diastolic dysfunction
heart cannot relax sufficiently
heart failure
-congestive heart failure (endpoint of cardiac diseases) -progressive -poor outcome
congestive heart failure leads to
-insufficient cardiac output -higher preload (higher filling pressure than normal) etiology:
-due to hyper PTH, anemia -abrupt in onset
-sometimes due to large MI, acute valve dysfunction
-most cases are gradual and subtle- cumulative chronic work overload / gradual loss of myocardium
-may be due to systolic /diastolic dysfunction
-endocarditis (leads to valve dysfunction)
restrictive cardiomyopathy
(stiff ,rigid, no thickened wall, less than normal ventricular filling)
Congestive heart failure
1) Develop from ischemia heart disease/ HTN which leads to systolic dysfunction (insufficient myocardial contractility) eventually to heart failure. 2) huge left ventricular hypertrophy, fibrosis of myocardium, deposition of amyloid, constrictive pericarditis (thickened, scarred sac)----- 1 1/2 of cases 3) higher frequency in aged individual, diabetic, women
forward cardiac failure
pump insufficient leads to increased end-diastolic volume thereby increased end-diastolic pressure
backward cardiac failure
-congestion of venous circulation -elevated venous pressure
compensation
decreased cardiac contractility
hemodynamic demand
frank-starling mechanisms
neurohumoral system activated
structural changes of myocardium
hypertrophy
compensated heart failure
-maintain normal cardiac output with dilated ventricles -mechanism
1) increased end-diastolic volume,
2) increase cardiac myofiber stretching
3) increased length of the muscle fiber
4) increased cardiac output
decompensated heart failure
-cannot maintain normal cardiac output due to failed myocardial muscles -mechanism-
1) increased wall tension over time
2) increased oxygen demand
neurohumoral compensation
-NE -RAAS
myocardial structural changes
pressure overload ( HTN , Valvular stenosis) volume overload (regurgitation, shunts)
pressure overload
parallel addition of sarcomere concentric hypertrophic - thickened wall without chamber dilation
volume overload
series addition of sarcomere heart weight increased dilated chamber with thicker/ normal / reduced thickness of the chamber
cardiac hypertrophy
increased oxygen demand
prone to ischemic injury as there is no additional capillary bed being formed despite increased in myocardial muscle mass
altered gene expression resemble to fetal myocytes eg: changes in dominant myosin heavy chain
ischemia n chronic workload
Apoptosis myocardial cells
Altered Cytoskeleton
Deposited extracellular matrix
sudden cardiac death
cardiac hypertrophy
pathology compensated hypertrophy
INCREASED mortality
physiology adaptations -volume-loaded hypertrophy due to regular aerobic exercise -accompany increase blood capillaries -reduced heart rate, Blood pressure
left-sided heart failure etiology
-ischemia heart disease -HTN -Mitral valve disease -Aortic valve disease -Amyloidosis (deposition of amyloids- can be in kidney as well) –decreased systemic perfusion -elevated pulmonary pressure
atrial fibrillation
hypertrophied left ventricle
dilated left ventricle
dilated left ventricle
-result in mitral valve insufficiency -left atrium enlargement -increased incidence of atrial fibrillation
microscopic changes in heart failure
-hypertrophied myocyte -interstitial fibrosis
acute left sided-heart failure
-raised pressure in pulmonary veins leads to transmission of pressure into the arteries and veins of the lungs result in congestion, edema. -pleural effusion occurs due to increase filtration (increased hydrostatic pressure) from the visceral pleura venules -perivascular and interstitial transudate -alveolar septa edema -edema fluid accumulated in alveolar spaces
chronic left-sided heart failure
-heart failure cells -phagocytosed leaked RBC (Hemosiderin-laden alveolar macrophage)
transudate
product of plasma filtration (ultrafiltrate)
exudate
product of inflammations
paroxysmal/sudden attack
azo- refer to nitrogen
engorgement is obstruction
cardiac decompensation
biventricular heart failure
progression of congestive heart failure
cyanotic acidotic
atresia
abnormal narrowing of the openings
claudication
pain (lack of blood supply to the muscles eg in the leg)
inception=formation
LEFT SIDED HEART FAILURE
Early symptoms
dyspnea on exertion cough (transudate in air spaces)
Disease Progression
-orthopnea (recumbent- straight lying down) -in supine position (enhanced venous return, diaphragm Is raised ,not pull by gravity- more blood to the right sided-heart ) -relieved by standing,
-sitting - reduced Venous return, diaphragm is pulled down slightly by gravity
Severe symptom
Paroxysmal nocturnal dyspnea
left ventricular failure
Cardiomegaly
Tachycardia
S3 (third heart sound)
Crackles sounds from the lungs (rales (crackling sounds) indicate edematous pooling at the opening alveoli of base of the lungs)
progressive dilatation
papillary muscles are displaced/ pulled outward
leaky valve (mitral regurgitation) manifested as systolic murmur
continue ATRIAL dilatation lead to atrial fibrillation manifested as irregular HEART BEAT.
Uncoordinated, irregular, chaotic atrial contractions
Decreased atrial contribution to ventricular filling, decreased ventricular stroke volume
blood stasis (not moving) in the atrial appendages
prone to formation of thrombus
shed thrombus form embolus
embolus travel to distant organs
causing obstructions
manifested as ischemia possibly proceed to infarction in other organs
decreased cardiac output
decreased renal perfusion
RAAS activations
increase intravascular (blood) volume via reabsorption of salt thereby water in the kidney & pressure via vasoconstriction (raised afterload)
failed heart
adding cumulative effect on pulmonary edema
further progression
prerenal azotemia (high nitrogen product in blood- sign of kidney failure)
severe congestive heart failure
-hypoxic encephalopathy -decreased cognitive function -stupor -restlessness
treatment
treat valvular dysfunction
treat cardiac inadequate perfusion
diuretics (for volume overload)
positive inotropes
adrenergic inhibitor (to reduce afterload)
ace inhibitor (opposed aldosterone, restrict cardiac hypertrophy +remodeling)
cardiac resynchronization therapy
cardiac contractility modulator
Right-sided Heart Failure etiology
normaly due to consequence of left sided heart failure due to congested pulmonary circulations (raised pulmonary pressure)
isolated right sided heart failure (cor pulmonae) etiology -from parenchymal lung disorders -from primary pulmonary HTN (common in cor pulmonae) which in turn lead to right-sided hypertrophy and dilation. -from recurrent pulmonary thromboembolism -from pulmonary vasoconstriction in people with obstructive sleep apnea
right-sided Hypertrophy and dilation
commonly restricted to the right ventricle and right atrium
uncommon in bulging to the left ventricular septum causing reduce cardiac output
clinical features
-obstruction in systemic n portal VENOUS system -less effect on pulmonary congestion -congestive hepatomegaly (passive congestion- appear like nutmeg liver) (congestion occur in centrilobular area, peripheral parenchyma is paler with no congestion) -if accompany with left sided heart failure- centrilobular necrosis and sinusoidal congestion -chronic right-sided heart failure, central fibrosis creating cardiac cirrhosis.
consequences
-portal HTN -congestive splenomegaly ( tense, enlarged spleen)-- -severe passive congestion lead to bowel wall edema -malabsorption of nutrients and medications
consequences of systemic venous congestion
transudates (effusion) into the pleural and pericardial space but don’t cause pulmonary edema
consequences of both left and right sided heart failure
-more pronounced pleural effusion -pulmonary edema
consequences of hepatic congestion (with or without reduced albumin synthesis) and portal HTN
-peritoneal effusion/ transudate (ascites)
uncomplicated effusions
low protein, low number of inflammatory cells
hallmark of right sided-heart failure
-edema in the feet and lower legs -no respiratory symptoms -venous congestion -hypoxia of kidney and brain
chronic bedridden patient
presacral edema
Congenital Heart Disease
abnormality of heart/great vessels
Types
- severe-intrauterine incompatibility
- perinatal incompatibility -cardiac malformation -unrecognised
incidence
-higher in premature birth -higher in stillborn
treatment
surgical intervention
secondary effect after surgical treatment
-arrhythmias -myocardial dysfunction
etiology of congenital heart disease
faulty embryogenesis (between week 3 to 8)
environmental exposure
congenital rubella infections
teratogens
maternal diabetes
genetic (autosomal dominant)
familial
-chromosomal abnormalities (chr 13,15, 18,21, turner syndrome)
cardiac morphogenesis
progenitor cells
myocardial lineage
myocardial formation
heart tube looping
heart tube segmentation
cardiac chamber growth
cardiac valve formation
great vessels connected to the heart
transformations mediators
transcription factors
signalling molecules
Wnt
Vascular endothelial growth (VEGF)
Bone morphogenic Protein (BMP)
Transforming growth factor B (TGF-B)
Fibroblast growth factor
Notch pathway
pulsatile, flowing blood (sensed by the developing cells of the heart and the vessels)
transcription factors mutations
Atrial Septal Defect
Ventricular Septal Defect
Conduction Defect
TBX5 mutation--(T-box 5 protein (tf)-important in growth n development of heart (eg the electrical system of the heart/ the conduction system of the heart) n upper limbs
Holt-oram syndrome
intracellular signaling mutations
Noonan syndrome
types malformations
left to right shunt
right to left shunt (cyanotic)
obstructions
left to right shunt (atrial septal defect, ventricular septal defect, patent ductus arteriosus)
increase blood volume to the lungs
increase pulmonary resistance
right ventricular hypertrophy
right sided-heart failure
shunt reversal
late onset cyanosis
completely asymptomatic to sudden/fulminant heart failure
vascular flow obstruction
complete- atresia
chamber, valve, blood vessels narrowing
tetralogy of fallot
-pulmonary stenosis -shunt via ventricular septal defect
defects (heart)
some causes hypoplasia (reduced muscle mass)
- develop atrophy post-natal
effect of atrial septal defect
elevated right ventricular n pulmonary outflow volume
effect of ventricular septal defect and patent ductus arteriosus
raised pulmonary blood flow raised pulmonary blood pressure
chronic left to right shunting
-pulmonary HTN chronic right to left shunting-cyanosis
(Eisenmenger syndrome) -irreversible structural defect -require early interventions
foramen ovale
ostium primum ostium secundum
tissue flaps
septum primum septum secundum
fusion of the septa via high pressure left atrium
20% unsealed foramen ovale
patent foramen ovale
valsalva maneuver (patent foramen ovale)
-sneezing -straining during bowel movement
paradoxical embolism (patent foramen ovale)
-venous emboli from deep leg vein
atrial septal defect
-fixed opening -ostium secundum (inadequate growth of the septum secundum to occlude the second ostium
*atrial septal defect not the same as patent foramen ovale
ostium secundum
-smooth-walled defect near foramen ovale
chronic increased in volume loads
-right atrium dilation -right ventricle dilation -right ventricular hypertrophy -pulmonary artery dilation
ostium primum (atrial septal defect)
-lowest part of atrial septum -mitral/ tricuspid valve abnormal -additional defects : ventricular septal defect common AV canal
development of septum primum
located near to the endocardial cushions
sinus venosus atrial septal defect
high up in the atrial septum
drainage of pulmonary veins into the right atrium
drainage of pulmonary veins into the superior vena cava
onset of atrial septal defect
asymptomatic in child hood
adult onset
*ventricular septal defect is more common but close spontaneously
*chronic volume and pressure overloads cause pulmonary HTN
surgical closure of intravascular atrial septal defect
1) prevent heart failure from developing 2) prevent paradoxical embolism
3) prevent irreversible pulmonary vascular diseases
ventricular septal defect
formation of the ventricular septum
growth of muscular ridge upwards from the apex
growth of membranous partition of the endocardial cushions downward
fusion of both the muscular ridge and membranous partition
basal (membranous) region of the septum (last part to develop)
ventricular septal defect
90% close spontaneously (muscular portion) in childhood
20-30% occur in isolation
remaining - associated with cardiac malformations
Defect types
minute/ small defect in membranous septum
virtually defect in the entire interventricular wall
left to right shunt
-right ventricular hypertrophy
-increased diameter of pulmonary artery due to increased in right ventricular output and right ventricular pressure
-pulmonary HTN -congestive heart failure
things happen more frequent in ventricular septal defect than atrial septal defect
reversal of shunt (right to left) as a result of pulmonary HTN
cyanosis
jet lesion in the right ventricle
causes endothelial damage increased risk for infective endocarditis
patent ductus arteriosus
join from left pulmonary artery to the aorta
normally within 1 to 2 days after birth ductus arteriosus constricts and closes
stimulus induce closure of ductus arteriosus
elevated arterial oxygenation
reduced in pulmonary vascular resistance
decreased prostaglandin E2 level
obliteration leaving behind strands of fibrous tissue (ligamentum arteriosum)
delayed/ absent in closure etiology -hypoxia (due to respiratory distress or heart disease)
left to right shunt
patent ductus arteriosus
large defect of the patent ductus arteriosus
-lead to eisenmenger syndrome eventually -cyanosis eventually -congestive heart failure
*high pressure shunt predispose to infective endocarditis *
aortic/ pulmonic atresia
sustain patent ductus arteriosus with prostaglandin E
cyanosis
tetralogy of fallot
transposition of great vessel (switch position)
severe systemic cyanosis
1)clubbing of the tips of fingers 2)clubbing of the tips of toes
hypertrophic osteoarthropathy (periosteal reaction of the long bone without underlying bone lesion)
tetralogy of fallot
ventricular septal defect
right ventricular outflow obstruction/ subpulmonic stenosis
aortic overriding of the ventricular septal defect
right ventricular hypertrophy
septum between the pulmonary trunk and aortic root
-anterosuperior displacement of the infundibulum septum
enlarged heart, boot
-right ventricular hypertrophy -dilated aorta -hypoplasia of pulmonary trunk -right ventricular hypertrophy
*overriding aorta : outflow of blood from both ventricles
obstructed right ventricular outflow
subpulmonic stenosis
pulmonary valve stenosis
complete valvular atresia
complete proximal arteries atresia
obstructed right ventricular outflow
solutions
persistent patent ductus arteriosus
dilated bronchial arteries
tetralogy of fallot
1)right to left shunting 2) decreased pulmonary blood flow
3) increased aortic volumes
4) severity dependent on the degree of pulmonary outflow obstruction
mild pulmonary obstruction
resemble ventricular septal defect no cyanosis left to right shunt
pulmonic outflow stenosis
protection to pulmonary vasculature from pressure and volume overload
no pulmonary HTN
rare right ventricular failure
cyanosis
polycythemia (high rbc)(result from hypoxia)
hypertrophic osteoarthropathy
right to left shunting
risk of infective endocarditis
systemic embolism
hyperviscosity- extra red blood cells blocked / slow the blood flow in smaller blood vessels result in ischemia
transposition of great arteries
-INCOMPATIBLE WITH LIFE -unless left to right shunt occurs as in the ventricular septal defect -hypoplastic left ventricle -hypertrophy right ventricle -immediate surgical intervention
subpulmonic stenosis
obstruction closer to the valve
congenital obstructions
pulmonic valve stenosis
aortic valve stenosis
aortic valve atresia
coarctation of the aorta
aortic coarctation
twice affect more in male than female
turner syndrome (normally have coarctation)
two forms
: 1) infantile/ preductal (hypoplasia of aortic arch) close to patent ductus arteriosus- right ventricular hypertrophy
2) adult/ postductal form (ridge-like infolding of the aorta-from smooth muscles and elastic fibers of aortic media) (onset -later in life)- left ventricular hypertrophy
pre-ductal- dilated pulmonary trunk
post-ductal dilated aortic arch and branch vessels
pre-ductal coarctation
1)cyanosis at lower half of the body 2) die in neonatal period without intervention
post-ductal coarctation
upper extremity HTN
weak pulses
lower extremity hypotension
lower extremity claudication
lower extremity coldness
exuberant collateral circulations (enlarged intercostal and internal mammary arteries-seen as notching of the ribs)
significant coarctation
palpable thrill systolic murmur
treatment with balloon dilation, stent, surgical resection, end to end anastomosis , prosthetic graft
Ischemia Heart Disease
Imbalance of
cardiac perfusion
oxygen
nutrients
etiology
1)obstructive atherosclerotic vascular disease -causes decreased coronary blood flow -atherosclerotic coronary artery
onset in childhood/ adult
cardiac ischemia etiology
increased heart rate
HTN
Hypotension
shock
pneumonia
CHF
anemia
CO poisoning
cardiac syndrome
angina pectoris
(stable, exertion onset)
prinzmetal angina (vessel spasm)
unstable (at rest, less exertion onset)
MI-dependent on the severity and duration of the ischemia
Chronic ischemia heart disease with congestive heart failure- cardiac decompensation (progression)
sudden cardiac death
cardiac decompensation etiology
acute MI
Accumulated ischemia insults (mechanical pump failure)
reduce risk factor
1) smoking 2) HTN
3) diabetes
therapy
1)aspirin prophylaxis 2) control arrhythmia
3) thrombolysis
4) endovascular stent placement
5) angioplasty
6) coronary bypass graft surgery
IHD is a consequence of preexisting atherosclerotic occlusion of the coronary artery with superimposed thrombosis / vasospasmatheroslcerotic artery
left anterior descending artery
left circumflex artery
right coronary artery
secondary branch of atherosclerosis
diagonal branch of left anterior descending artery
obtuse marginal branch of left circumflex artery
posterior descending branch of right coronary artery
critical stenosis
70% obstruction of the lumen
fixed stenosis
>70%stable angina
fixed stenosis reach >90%
unstable angina with insufficient coronary blood flow
low rate atherosclerotic lesion
-allows coronary vessels remodeling -in acute coronary blockage, such compensation does not occur
inflammation
interaction with EC, leukocyte circulation, T cell and macrophage recruitment n activations
these cellls drive smooth muscle cells proliferation, accumulation, matrix production, superimposed atheroma (With lipid, cholesterol core, calcified, necrotic debri)
macrophage metalloproteinase secretion to destabilise the plaque
thrombosis
erosion and rupture of the plaque --- lead to acute coronary syndrome
lead to unstable angina / sudden cardiac death
subendocardial infarction
partial luminal occlusion by thrombus
mural thrombi
embolization
unstable angina 1)possibly microinfarct
plaque disruption
increased local mechanical shearing forces
increased vessel spasms
stimulus to vasoconstriction
circulating adrenergic agonist
local platelet content release
imbalance between endothelial relaxing and contracting factors
mediators released by perivascular inflammatory CELLS (eg: neutrophils, macrophage, eosinophils, mast cells, lymphocytes, plasmacytes)
acute plaque change
acute coronary syndrome
may lead to
unstable angina
sudden cardiac death
infarction
stimulus that EXPOSE thrombogenic constituent / subendothelial basement membrane
rupturing
fissuring
ulceration
types of obstructions
fixed coronary obstruction (in typical angina)
severe, fixed coronary obstruction ( in chronic IHD)
mural thrombus obstruction (in unstable angina, acute subendothelial myocardial infarction, sudden cardiac death)
occlusive thrombus (acute transmural myocardial infarction, sudden cardiac death)
stimulus for plaque erosion
endothelial injury
apoptosis
inflammatory
toxic exposure
factors predispose to plaque rupture
thin fibrous cap
fissures with high mechanical stress
factors determine plaque stability
fibrous cap remodeling (balance of collagen synthesis and collagen degradation)
metalloprotease secreted by the macrophage degrade the collagen of the fibrous cap
paucity / scarcity of the smooth muscles cells (prone to rupture)
large number of inflammatory cells (prone to rupture)
statin increase plaque stability and reduce plaque inflammation (in both coronary arterial disease and ischemia heart disease)
adrenergic stimulation leads to HTN, local vasospasm which increase physical stress exert on the plaque
high incidence of acute MIbetween 6am to noon
angina pectoris
intermittent chest paindefinetransient reversible myocardial ischemiacauses
typical/ stable angina
prinzmetal/ variant angina
unstable angina/ crescendo angina
variantsischemia-induced -release of adenosine -bradykinin -autonomic nerve stimulationpain mediators
crushing
squeezing substernal sensation radiates from the left arm to the left jaw (as referred pain)
pain relieved by rest
treat with drugs such as vasodilator (nitroglycerin)
symptoms and treatment of stable angina1)occurs at rest
2)coronary artery spasm
treat with( vasodilator ,nitroglycerin, calcium channel blocker)
etiology, symptoms, treament of prinzmetal/ variant angina1)occurs at rest, occur with less exertion
plaque disruption, superimposed thrombosis, distal embolization, vasospasm- sign of MI
symptoms and etiology of crescendo/unstable angina
MI
heart attacknecrosis of heart musclefrequency
10% before age 40
45% before age 65
men greater risk
menopause higher risk
etiology OF MI
acute thrombosis within the coronary artery
exception1)transmural infarction occur in the absent of occlusive atherosclerotic vascular diseasesetiology of TRANSMURAL INFARCTION
coronary artery vasospasm
mural thrombus embolization
atrial fibrillation
valvular vegetation
RARE
subendocardial infarction absent of thrombus and embolus
endomyocardium-most distal to the epicardial vessels
other ischemia etiology (absent of atherosclerosis, thromboembolic disease)
1)small intramyocardial arterioles (eg: vasculitis, amyloid deposition, stasis, SCA)
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