Atrial Septal Defect (ASD)
Atrial Septal Defect (ASD)
•
• Incomplete closure of the fossa ovalisIncomplete closure of the fossa ovalis ÆÆallowing inter-arterial communicationallowing inter-arterial communication •
• Often a mild disease not detected until adult lifeOften a mild disease not detected until adult life
o
o Due to pressure and volume handled by the atria level is lower compared to the systemic levelDue to pressure and volume handled by the atria level is lower compared to the systemic level
•
• Pulmonary flow is increased to about twice the Pulmonary flow is increased to about twice the systemic outputsystemic output
o
o Pressure (Left > Right)Pressure (Left > Right) o
o blood preferentially goes from Left blood preferentially goes from LeftÆÆRight atrium =Right atrium =↑↑Pulmonary blood flowPulmonary blood flow
•
• RV is dilated and hypertrophiedRV is dilated and hypertrophied
o
o Adaptation of the right ventricle to theAdaptation of the right ventricle to the ↑↑ workload(hypertrophy)workload(hypertrophy)ÆÆdilatationdilatation
Complication Complication
o
o Pulmonay HPNPulmonay HPN o
o RV failure (due to dilatation)RV failure (due to dilatation)
death also from CHF (due to arrhythmia) and IHDdeath also from CHF (due to arrhythmia) and IHD
o
o Shunt reversal (Late cyanosis)Shunt reversal (Late cyanosis)
↑↑ pressure from right side to leftpressure from right side to left
Mixing of unoxygenated blood Mixing of unoxygenated blood from right side to the leftfrom right side to the leftÆÆto systemic circulationto systemic circulation
ASD ASD
Types: Types: 1.
1. Fossa or Ostium seccundum (most common)Fossa or Ostium seccundum (most common) 2.
2. Outlet (Primum SD)Outlet (Primum SD) 3.
3. Sinus Venosus defectSinus Venosus defect 4.
4. Coronary sinus defectCoronary sinus defect
Fossa Ovalis
Ventricular Septal Defect (VSD)
Ventricular Septal Defect (VSD)
•
• Most common cardiac anomaly in children (recognized early)Most common cardiac anomaly in children (recognized early) •
• incomplete closure of ventricular septumincomplete closure of ventricular septumÆÆleft to right interventricular communicationleft to right interventricular communication
o
o inadequate growth or absent fusion of embryologic septal componentsinadequate growth or absent fusion of embryologic septal components
•
• Increases risk for infective endocarditisIncreases risk for infective endocarditis •
• Functional disturbance depends on the size of the defectFunctional disturbance depends on the size of the defect
o
o ↑↑defect =defect = ↑↑disturbance and vice versadisturbance and vice versa o
o Small defects can sometimes close spontaneously as the heart enlargesSmall defects can sometimes close spontaneously as the heart enlarges o
o Surgery (1Surgery (1ststyear) to prevent irreversible obstructive pulmonary vascular diseaseyear) to prevent irreversible obstructive pulmonary vascular disease
•
• Large VSDs result in overload of both Large VSDs result in overload of both ventriclesventricles
o
o Similar to ASD (movement is from LSimilar to ASD (movement is from LÆÆR)R) o
o Right ventricle carries the initial burdenRight ventricle carries the initial burden
Complications Complications
•
• Eisenmenger syndromeEisenmenger syndrome
o
o Pulmonary HPNPulmonary HPN o
o shunt reversalshunt reversal o
o cyanosis (Late cyanosis)cyanosis (Late cyanosis)
VSD VSD Muscle band Muscle band Muscle band Muscle band Infraventricularis Defect Infraventricularis Defect Supraventricularis Defect Supraventricularis Defect
Patent Ductus Arteriosus (PDA)
• 90% occur as isolated anomalies (common in babies whose mothers had rubella) • Rough machine-like murmur (S4) on auscultation
• Permanent closure of the DA is usually complete by 8 weeks after birth
o Patency due to failure to contract and become fibrotic in response to↑arterial oxygen o Large caliber of the ductusÆincomplete closure
• should be closed as early in life as feasible
Complications PDA o Pulmonary HPN o Shunt reversal o Cardiac hypertrophy Adaptation to↑ workload
eventually leads to heart failure
o Dilated pulmonary artery
Pulmonary Artery
Aorta take note of the 3 branches
Patent Ductus Arteriosus
Left Pulmonary Artery
Left Pulmonary Artery
Patent Ductus Arteriosus(w/ probe)
Pulmonary Artery (Opened) Aorta O ened
Tetralogy of Fallot
• Most common cyanotic congenital anomaly • Four Components:
o Large VSD
o Stenosis of pulmonary outflow tract
Narrowing of the lumen due to subpulmonic muscle block
o Biventricular origin of the aorta (overrides the right ventricle) septal defect is below overriding aorta
receives blood from the RV and LVÆEARLY cyanosis
o Right ventricular hypertrophy
0.6-1cm thick (normal – 0.5cm)
• results from anterosuperior & leftward displacement of the infundibular septum
Complications Left to Right Shunt Initial LÆR Shunt No Shunt Tetralogy of Fallot VSD
PDA ASD PTA
Coartaction of the aorta Pulmonary stenosis Aortic stenosis
o Heart failure o Polycythemia
o ↑ risk for thrombosis o ↑ risk for infective
endocarditis Aorta Stenotic VSD RV hypertrophy VSD Stenosis RV hypertrophy
Pulmonary Hypertension
in Congenital HD w/ Left and Right ShuntsTunica Adventitia
Grade IV – Plexiform Lesions (Irreversible)
Newly formed Capillaries Fibrous Tissue
Grade III – Intimal Fibrosis (Irreversible)
Hypertrophied Tunica Media
Fibrous tissue in the Tunica Intima (Occlusion of the lumen)
Grade II – Intimal Hyperplasia (Reversible)
Hypertrophied Tunica Media Internal Elastic Membrane
External Elastic Membrane Intimal Hyperplasia
External Elastic Membrane
Internal Elastic Membrane Tunica Intima
Single layer of Endothelial cells (simple squamous)
Hypertrophied Tunica Media
Rheumatic Heart Disease
• cardiac involvement in rheumatic fever
• Rheumatic Fever: immunologic hypersensitivity rxn to Strep antigens (NO BACTERIA present)
o Ig & complement demonstrable in myocardial fiber membrane
o Cross reacting Ab against Strep protein and myocardial sarcolemma in patient’s sera
Ab w/c supposedly should be specific for Strep antigen will also attack the tissue of the heart due to similarity of the heart’s antigen to the strep antigen
• Jone’s Criteria: 2 major or 1 major + 2 minor
Major Criteria Minor Criteria
Carditis Polyarthritis Chorea
Subcutaneous nodules Erythema marginatum
RHD or previous rheumatic fever Athralgia
Fever
Elevated esr Postive CrP Leukocytosis
Prolonged PR interval on ECG
Acute Lesion
Pancarditis (all layers) Pericarditis– fibrous type
Endocarditis– verrucae along lines of closure of valve leaflets
Myocarditis – Aschoff bodies in granulomatous stage (histologic hallmark of rheumatic ac tivity)
Pericarditis (Gross)
Fibrous type
( Bread and Butter Pericarditis)
Pericarditis (Microscopic)
Fibrin de osits
Epicardial layer
Rheumatic Heart Disease
Endocarditis (Gross)
Mitral Valve
(Translucent = Normal)
Verucae
(Vesicle like structures)
Thickened Papillary Muscles
Endocarditis (Microscopic)
Fibrin deposits
Neutrophilic infiltrations
Aschoff Bodies in Myocarditis
• special type of interstitial inflammation
• a perivascular focus of swollen eosinophilic collagen surrounded by lymphocytes, monocytes and plasma cells
Three Stages
1. Exudative stage 2. Granulomatous stage 3. Healed Stage
Exudative Stage
Exudate with
Neutrophilic infiltrations Blood Vessel Lumen
Cardiac Muscles
Granulomatous Stage
Granuloma formation
(with epithelial histiocytes and macrophages)
Healed Stage
Myocardial layer Blood Vessels
Rheumatic Heart Disease
Chronic Lesion
• commisures fused; cusps thickened and fibrotic; chordae tendinae thickened, shortened and fused • Most commonly involved valve- mitral, alone or in combination with others
Fused Commisures Fibrotic and smooth mitral valve
Deformed orifice
(Fish Mouth Deformity)
Short, thickened and fused together
Infective Endocarditis
• Invasion of the heart by microbiologic agent (friable vegetations laden with organisms) • Predisposing factors:
o Rheumatic heart disease (valves become fibrotic), congenital heart disease, calcific stenosis,
artificial valves, immunodeficiency/ immunodepression, IV drug abuse Types:
ACUTE SUBACUTE
virulent organisms
affects previously normal valve highly destructive
bulkier vegetations
valve perforation common
low virulence
superimposed on damaged valves; less destructive
smaller vegetations
Complications:
• Sepsis
• Cardiac – valve insufficiency, myocardial abscess • Embolic
• Renal – embolic infarction, focal glomerulonephritis, abscesses
Bulky Vegetations Aortic Valve
Vegetations
Mitral Valve Prolapse (Floppy Valve)
• Degenerative change, in 6% of population, young women
• Accumulation of mucopolysaccharides in valve leaflet causing ballooning of the valve • Myxomatous degeneration of spongiosa layer, degeneration & attenuation of fibrosa layer
Three Layers of the Valve
1. Auricularis layer (from atrium) 2. Ventricularis layer (from ventricles) 3. Spongiosa layer Æthickens
Complications
• Mitral Insufficiency • Chordal rupture
o Due to stretching
• Infective endocarditis
Abundant amount of tissue (Bulging appearance)
Thin Ventricularis layer
Thin Auricularis layer
Thick Spongiosa layer Myocardial layer
Ischemic Heart Disease
Syndromes resulting from imbalance between supply and demand of the heart for oxygenation 1. Increased demand (increased heart rate)
2. Diminished oxygen transport (sever anemia, congenital h eart disease) 3. Diminished coronary blood flow
Coronary atherosclerosis is the most common cause of diminished blood flow 1. 75% narrowing is significant
2. Stenosis within 2cm of left anterior descending and circumflex artery
Ischemic syndromes 1. Angina pectoris 2. Myocardial infarct 3. Sudden cardiac death
Calcium deposits
(make vessel more brittle)
Large deposits of Atheromatous plaques
Narrowed lumen
Blood clot
(complete occlusion)
↑ BPÆinjures the surface of the blood vessel Æcoagulation cascadeÆ
Myocardial Infarct
Transmural – necrosis of full thickness of the LV wall, a ssociated with occlusive thrombi in 90%
Subendocardial – necrosis limited to inner 1/3, diffuse coronary atherosclerosis, no thrombus
Infarct ( Left Main CA)
Full Thickness of the Ventricle
(Anterior wall, anterior 2/3 of septum and lateral ventricular wall)
Infarct ( Left Main CA and Right CA)
(Anterior wall, anterior 2/3 of septum, lateral ventricular wall and posterior wall)
yocardial Infarct
M
Wavy myocardial fibers
½ to 1 hr After Myocardial Infarct
Early Coagulation Necrosis
<12 hr After Myocardial Infarct
Full Blown Coagulation Necrosis (Inflammatory cells to take up the dead myocardial fibers)
3-7 days After Myocardial Infarct
Fibrosis
(Disappearance of dead myocardial cells)
Myocardial Infarct
plications
• Cardiac arrhythmias
• Left ventricular failure with pulmonary edema
o Decreased hydrostatic pressure
• Cardiogenic shock
o Failure of the heart as a pump
• Myocardial rupture • Thromboembolism
o Relaxation of the muscle wall during an infarctÆstasis of blood Æpromotes coagulation o CoagulationÆmural thrombosis (fragile) Æfragmented and turns into an embolus
Com
Infarct
Rupture of the infarct part of the heartÆcollection of blood in the pericardial sac
opathy
• Failure of the ventricle to empty in systole
ased ventricular end-systolic and diastolic volumes – biventricular dilatation and failure ic features – irregular hypertrophic and atrophic myocardial fibers with
holism, delayed pregnancy, hypo and hyperthyroidism
Congestive Cardiomy
• Incre
• Non-specific histolog
progessive fibrosis
• No detectable cause • associated with alco
Normal Carotid Sinus Normal Aortic Valve Normal Mitral Valve Normal Chordae Tendinae
Dilated Ventricle
Everything is normal except the biventricular dilatation
Fibrous tissue
(between the fibers)
Fibrous tissue
(between the fibers) Hypertrophy
y
le with resistance to diastolic filling
ized myocardial fibers
Hypertrophic Cardiomyopath
• Marked hypertrophy of the ventricular musc
• 20-30% are familial, autosomal dominant inheritance pattern • Greater thickening of ventricular septum than the LV free wall • Histology: disorgan
Thick Septum Aorta
Bulge prevents blood flow to Aorta Left Ventricle
Right Ventricle
Subaortic stenosis due to thick septum Right Atrium enlargement
Asymmetric Septum
Disorganized myocardial fibers
Obliterative Cardiomyopathy
• Marked subendocardial fibrosis – encroachment of the lumen, decreased ventricular filling and
cardiac failure
• Endocardial fibroelastosis – collagen and elastic tissue is laid down beneath the endocardium in
infancy
• Endomyocardial fibrosis, common in Africa
Restrictive Cardiomyopathy
• Decreased compliance of the ventricular muscle, increased resistance to filling, and cardiac failure • Many cases are due to cardiac amyloidosis
Mitral Valve
(translucent = normal)
Overwhelming deposits
(Obscured Trabeculae Carnae)
Thrombus
Endocardial Fibrosis (whiteness of the wall)
t sources)
