Heart Flashcards
effects of aging on myocardium
Increased mass Increased subepicardial fat Brown atrophy Lipofuscin deposition Basophilic degeneration Amyloid deposits
Older persons develop small filiform processes _______________ on the closure lines of aortic and mitral valves resulting from the organization of small thrombi
(Lambl excrescences)
extensive lipofuscin deposition in a small, atrophied heart; often accompanies cachexia, as seen in terminal cancer
Brown atrophy
Categories of Heart Dse
Congenital Heart Abnormalities Ischemic Heart Diseases Heart diseases caused by Hypertension Heart diseases caused Pulmonary diseases (cor pulmonale) Diseases of the Cardiac valves Primary cardiac diseases
SIX PRINCIPLES OF PATHOLOGY
Pump failure Obstruction to flow Regurgitant to flow Shunted flow Disorders of cardiac conduction Rupture of the heart or a major vessel
Occurs when the heart is unable to pump blood at a rate sufficient to meet the metabolic demands of the tissues
CARDIAC HEART FAILURE
Physiologic mechanisms maintain arterial pressure and perfusion of vital organs in HF
Frank-Starling mechanism
Myocardial adaptations (hypertrophy)
Activation of neurohumoral system
o Occurs in response to increases in pressure
o Usually due to hypertension or aortic stenosis
o Causes a concentric increase in wall thickness
Pressure-overload hypertrophy
o Characterized by ventricular dilation
o the new sarcomeres assembled are positioned in series with existing sacromeres
o As a result, the wall thickness may be increased, normal, or less than normal
o Heart weight, rather than wall thickness, is the best measure of hypertrophy in volume overloaded hearts
Volume-overload hypertrophy
3x or 4x the normal weight of the heart
aortic regurgitation
hypertrophic cardiomyopathy
Causes:of LEFT-SIDED HEART FAILURE
o Ischemic heart disease
o Hypertension
o Aortic and Mitral valvular heart disease
o CO is preserved at rest, but the left ventricle is
abnormally stiff or otherwise restricted in its ability to relax during diastole
o Because the left ventricle cannot expand normally, any increase in filling pressure is immediately referred back to the pulmonary circulation
Systolic failure
o There is rapid onset pulmonary edema (aka flash
pulmonary edema)
Systolic failure
o Reduction in the ability of the left ventricle to relax
and fill
Diastolic failure
o are the hemosiderein-laden macrophages
o phagocytosed RBCs store the iron recovered from
hemoglobin
Heart failure cells
o Pure right-sided heart failure
o Associated with parenchymal diseases of the lung
o Pulmonary hypertension
Cor pulmonale
Most common congenital heart disease
VSD
Most common genetic cause of congenital heart disease is
trisomy 21 (Down syndrome)
MAJOR CATEGORIES OF CONGENITAL HEART DISEASE
Malformation causing a Left to Right Shunt
Malformation causing a Right to Left Shunt
Malformation causing an Obstruction
Causes of R–>L shunt
- Tetralogy of Fallot
- Transposition of the great arteries
- Persistent truncus arteriosus
- Tricuspid atresia
- Pulmonary venous connection
Most commonly encountered LRS
- ASD
- Patent foramen ovale
- VSD
- Patent ductus arteriosus
- AV septal defects
result from a
deficient or fenestrated oval fossa near the center of the
atrial septum
Secundum ASDs (90%)
occur adjacent to the
AV valves
Primum anomalies (5% of ASDs)
are located near the
entrance of the superior vena cava and may be
associated with anomalous pulmonary venous return to
the right atrium.
Sinus venosus defects (5%)
Complications of ASD?
o heart failure
o paradoxical embolization
o irreversible pulmonary vascular disease.
is an abnormal, fixed opening in the atrial septum caused
by incomplete tissue formation
ASD
a small hole created by an open flap of tissue in the atrial
septum at the oval fossa
PATENT FORAMEN OVALE
Incomplete closure of the ventricular septum, allowing free
communication of blood between the left to right ventricles
VSD
About 90% of VSD; involves the region of the membranous interventricular
septum
Membranous VSD
lie below the pulmonary valve () or within
the muscular septum.
Infundibular VSD
VSDs in the muscular septum may be multiple and called?
“Swiss-cheese” septum
Harsh “machinery-like” murmur
PATENT DUCTUS ARTERIOSUS
results when the ductus arteriosus remains open after birth
Patent (also called persistent) ductus arteriosus (PDA)
preservation of ductal patency is done by administering
prostaglandin E
ATRIOVENTRICULAR SEPTAL DEFECT other names
COMPLETE ATRIOVENTRICULAR CANAL DEFECT
ENDOCARDIAL CUSHION DEFECT
results from the
embryologic failure of the superior and inferior endocardial
cushions of the AV canal to fuse adequately
ATRIOVENTRICULAR SEPTAL DEFECT
consequences of ATRIOVENTRICULAR SEPTAL DEFECT
o incomplete closure of the AV septum
o malformation of the tricuspid and mitral valves
Forms of ATRIOVENTRICULAR SEPTAL DEFECT
Partial AVSD
Complete AVSD
consisting of a primum ASD and a cleft
anterior mitral leaflet,causing mitral insufficiency
Partial AVSD
consisting of a large combined AV
septal defect and a large common AV valve—
essentially a hole in the center of the heart
Complete AVSD
The diseases in this group cause cyanosis early in postnatal
life (cyanotic congenital heart disease)
RIGHT TO LEFT SHUNTS
is the most common disease in this group
Tetralogy of Fallot
RIGHT TO LEFT SHUNTS
Tetralogy of Fallot
persistent truncus arteriosus
tricuspid atresia
total anomalous pulmonary venous connection
TETRALOGY OF FALLOT Four cardinal features
VSD
(subpulmonary stenosis)
an aorta that overrides the VSD
right ventricular hypertrophy
“boot-shaped” heart
TETRALOGY OF FALLOT
mild TOF: the abnormality resembles an isolated VSD, and the shunt may be left-to-right, without cyanosis
pink tetralogy
ventriculoarterial discordance; the aorta arises from the right ventricle, and lies anterior and to the right of the pulmonary artery, which emanates from the left ventricle
TRANSPOSITION OF THE GREAT ARTERIES
Right ventricular hypertrophy becomes prominent, because this chamber functions as the systemic ventricle (what dse)
TGA
developmental failure of separation of the embryologic truncus arteriosus into the aorta and pulmonary artery
Persistent Truncus Arteriosus
Complete occlusion of the tricuspid valve orifice
Tricuspid Atresia
pulmonary veins fail to directly join the left atrium, results embryologically when the common pulmonary vein fails to develop or becomes atretic
Total Anomalous Pulmonary Venous Connection
OBSTRUCTIVE CONGENITAL ANOMALIES
COARCTATION OF AORTA
PULMONARY STENOSIS AND ATRESIA
AORTIC STENOSIS AND ATRESIA
form with tubular hypoplasia of the aortic arch
proximal to a patent ductus arteriosus that is often
symptomatic in early childhood
infantile
form in which there is a discrete ridgelike infolding
of the aorta, just opposite the closed ductus arteriosus (ligamentum arteriosum)distal to the arch vessels
“adult”
(“notching”) of the undersurfaces of the ribs –collateral circulation of the intercostal & mammary arteries assoc with what dse?
Coarctation of Aorta
Coarctation of aorta is associated commonly with what syndrome?
Turner syndrome
Congenital narrowing and obstruction of the aortic valve can
occur at three locations
Valvular
Subvalvular
Supravalvular
Syndrome of Ischemic Heart Disease/CAD: Presents as one or more of the ff:
Myocardial infarction (MI)
Angina pectoris
Chronic IHD with heart failure
Sudden cardiac death
Leading cause of death worldwide for both men and women
Ischemic Heart Disease/CAD
The coronary artery that perfuses the
posterior third of the septum (called “dominant” coronary arteries)
Right coronary artery
Left circumflex
Paroxysmal and usually recurrent attacks of substernal or precordial chest discomfort
ANGINA PECTORIS
Three Types of Angina pectoris
Stable (Typical) Angina
Prinzmetal Variant
Unstable (Crescendo) Angina
Increase in myocardial oxygen demand that outstrip the ability of stenosed coronary arteries to increase oxygen delivery
Stable (Typical) Angina
Complicated by partially occlusive thrombosis and vasoconstriction severe but transient reductions in coronary blood flow
Prinzmetal Variant
Cause: disruption of an atherosclerotic plaque with superimposed partial (mural) thrombosis and possibly embolization or vasospasm (or both)
Unstable (Crescendo) Angina
“Heart attack”
Death of cardiac muscle due to prolonged severe ischemia
MYOCARDIAL INFARCTION
initial event: sudden change in an atheromatous plaque
Coronary arterial occlusion
Progression of myocardial necrosis after coronary artery occlusion
MYOCARDIAL RESPONSE
Onset of: ATP depletion \_\_\_\_\_\_\_\_ Loss of contractility \_\_\_\_\_\_\_ ATP reduced: to 50% of normal \_\_\_\_\_\_ to 10% of normal \_\_\_\_\_\_ Irreversible cell injury \_\_\_\_\_\_\_ Microvascular injury \_\_\_\_\_\_\_
Seconds
1 hr
Ischemia is most pronounced in the (what zone in the heart)
subendocardium:
Most common infarction; Near full thickness (>60%) of the ventricular wall in the distribution of a single coronary artery
o “ST elevation infarcts
Transmural – (“Q” wave infarct)
Inner third to half of wall type of infarct; Normally the least perfused region: most vulnerable to
any reduction in coronary flow
Subendocardial (nontransmural)
o “Non-ST elevation infarcts”
Subendocardial (nontransmural)
o “ST elevation infarcts
Transmural – (“Q” wave infarct)
Most effective way to “rescue” ischemic myocardium
threatened by infarction
INFARCT MODIFICATION BY REPERFUSION
Severe ischemia lasting _______minutes or longer leads to irreversible damage
20 to 30
The typical changes of coagulative necrosis become
detectable in the first _____ hours.
6 to 12
result from the forceful systolic tugs of the viable fibers on immediately adjacent, noncontractile dead fibers
Wavy fibers
areas of necrosis are stained by (MI)
triphenyltetrazolium chloride
most common cause of death (90% of
cases)
Post infarct arrhythmia
complication of MI that is due to myocardial
inflammation
Fibrinohemorrhagic pericarditis
Also called DRESSLER SYNDROME
COMPLICATIONS OF MI
Post infarct arrhythmia
CHF – 60%
Hypotension and cardiogenic shock – 10%
Myocardial rupture – 1-5%
CHRONIC ISCHEMIC HEART DISEASE
Progressive heart failure as a result of ischemic myocardial damage
Unexpected death from cardiac causes early after symptom
onset (within 1hr) or without the onset of symptoms
SUDDEN CARDIAC DEATH
Causes pressure overload and ventricular hypertrophy; Most commonly seen in the left side of the heart
HYPERTENSIVE HEART DISEASES
Pulmonary HPN may cause:
o Right-sided HHD
o Aka COR PULMONALE
Cross section: Normal crescent shape of the RV is transformed to a dilated ovoid
Acute Cor Pulmonale
Due to stenosis, insufficiency (regurgitation or incompetence), or both
VALVULAR HEART DISEASE
failure of a valve to open completely
impediment of forward flow
o stenosis
failure of a valve to close completely
allowing reversed flow
o insufficiency
incompetence of valve stemming from an abnormality in one of its support structures
allowing reversed flow
o functional regurgitation
Most common of all valvular abnormalities
CALCIFIC AORTIC STENOSIS
most frequent congenital CV malformation in humans
CALCIFIC STENOSIS OF CONGENTITALLY BICUSPID AORTIC VALVE
degenerative calcific deposits develop in the peripheral fibrous
ring (annulus) of the mitral valve
MITRAL ANNULAR CALCIFICATION
“floppy” mitral valve
MITRAL VALVE PROLAPSE (MYXOMATOUS
DEGENERATION OF THE MITRAL VALVE)
Key histologic feature of MITRAL VALVE PROLAPSE
o Myxomatous degeneration
disease associated with mitral valve prolapse
Marfan’s Syndrome
Major Manifestations of Rheumatic Fever
o Migratory polyarthritis o Pancarditis o Subcutaneous nodule o Erythema marginatum of the skin o Sydenham Chorea
Minor Manifestations of Rheumatic Fever
o Fever
o Arthralgia
o ↑ blood levels of acute phase reactants
Aschoff bodies
o distinctive lesions in the heart
o consist of:
foci of lymphocytes (primarily T cells)
occasional plasma cells
Anitschkow cells: plump activated macrophages
o pathognomonic for RF
Anitschkow cells
o leaflet thickening
o commisural fusion and shortening
o thickening and fusion of the tendinous cords
Cardinal anatomic changes of the mitral valve in chronic RHD
o maplike thickening of endocardiumover lesions, usually in
left atrium
MacCallum’s plaques
more commonly:
o following recurrent ARF
Chronic Rheumatic Heart Disease
Heart disease resulting from a primary abnormality in the
myocardium
CARDIOMYOPATHY
o diseases predominantly confined to the heart muscle
Primary cardiomyopathies
o myocardial involvement as a component of a systemic or
multiorgan disorder
Secondary cardiomyopathies