Transcript Heart Congenital Diseases

HEART
DISEASES
Lecture I
Associate Professor
Dr. Alexey Podcheko
Spring 2015
INTENDED LEARNING OUTCOMES
CONGENITAL (CHD):
1. To know Cardiac Development
2. To know causes of CHD
3. Pathophysiology and clinical presentations of:
•
ASD, VSD, patent ductus arteriosus (PDA)
•
Tetralogy of Fallot
•
Transposition of the great arteries
•
Persistent Truncus arteriosus
•
Tricuspid atresia
•
Total anomalous pulmonary venous connection
•
COARCTATION of aorta
•
pulmonary stenosis/atresia
•
Aortic stenosis/atresia
THE HEART
• Normal
• Pathology
– Heart Failure: L, R
– Heart Disease
•
•
•
•
•
•
•
•
Congenital: LR shunts, RL shunts, Obstrustive
Ischemic: Angina, Infarction, Chronic Ischemia, Sudden Death
Hypertensive: Left sided, Right sided
Valvular: AS, MVP, Rheumatic, Infective, Non-Infective,
Carcinoid, Artificial Valves
Cardiomyopathy: Dilated, Hypertrophic, Restrictive, Myocarditis,
Other
Pericardium: Effusions, Pericarditis
Tumors: Primary, Effects of Other Primaries
Transplants
NORMAL Features
• 6000 L/day
• 250 to 300 gm in females and 300 to 350 gm in
males, or roughly 0.4% to 0.5% of body weight
• 40% of all deaths (2x cancer)
• Wall thickness ~ pressure
• (i.e., a wall is only as thick as it has to be)
-Right ventricle - 0.3 to 0.5 cm
-Left ventricle 1.3 to 1.5 cm
-Atria =.2 cm
Normal Features, Starling's Law of
the Heart
• ability of the heart to change its force
of contraction and therefore stroke
volume in response to changes in
venous return is called the FrankStarling mechanism (or Starling's Law of
the heart).
NORMAL Features
• The efficient pumping of blood by the heart
to the entire body requires the normal
function of each of its key components:
• 1. the myocardium
• 2. valves
• 3. conduction system
• 4. coronary arterial circulation
Which one is cardiac tissue?
A
B
Cardiac muscle cell has one nucleus (sometimes two).
Each cardiac muscle cell is branched, forming a tissue that is
appropriately described as a functional syncytium
Intercalated disks junctions types :
1. Fascia adherens
2. Desmosomes
3. Gap junctions (exchange of ions)
CONDUCTION SYSTEM of the
HEART
• Needed for coordinated contraction
of the cardiac muscle
• Presented by specialized excitatory
and conducting myocytes
• Key components :
• (1) the sinoatrial (SA) pacemaker of
the heart, (near the junction of the
right atrial appendage and the
superior vena cava)
• (2) the AV node (in the right atrium
along the atrial septum)
• (3) the bundle of His (courses from
the right atrium to the summit of the
ventricular septum)
• (4) the right and left bundle branches,
Left bundle brunch has anterior and
posterior fascicles!!!
• (5) Purkinje network
S.A. NodeAV NodeBundle of HIS L. Bundle, R. Bundle
Coronary arterial circulation
•
To meet their energy needs, cardiac myocytes rely almost
exclusively on oxidative phosphorylation, which is manifest
by the abundant mitochondria that are found in these cells
• cardiac myocytes extremely vulnerable to ischemia
• Coronary arteries:
-epicardial coronary arteries:
1. Left Coronary artery (LCA)
a. left anterior descending (LAD)
b. left circumflex (LCX) arteries, both arising from branches of
the left (main) coronary artery
2. Right Coronary artery (RCA)
a. Marginal
b. Posterior descending artery (in 85% of cases) and nodal
artery
• Most coronary arterial blood flow to the myocardium
occurs during ventricular diastole
Whichever artery winds up supplying the posterior interventricular septum is said
to be “DOMINANT”
VALVES
• AV:
–TRICUSPID
–MITRAL
• SEMILUNAR:
–PULMONIC
–AORTIC
Valves
• Their function depends on the mobility, pliability, and structural
integrity of their delicate flaps, called leaflets (in the tricuspid
and mitral valves) or cusps (in the aortic and pulmonary valves,
also known as the semilunar valves).
• layered architecture :
• 1. lamina ventricularis (tight network of reticular fibres )
• 2. lamina radialis (radial orientated collagenous and elastic
fibres)
• 3. lamina spongiosa (loosely arranged reticular fibres with
bundles of collagenous and some elastic fibres)
• 4. lamina fibrosa (Circular arranged collagen fibres )
• 5. lamina arterialis
Schematic drawing of aortic root structures after longitudinal opening of the root.
Schematic drawing of aortic root structures after longitudinal opening of the root.
VALVES
• The function of the semilunar valves depends on
the integrity and coordinated movements of the
cuspal attachments.
• Dilation of the aortic root can hinder cooptation
of the aortic valve cusps during closure, yielding
regurgitation.
• The competence of the atrioventricular
valves depends on not only the leaflets and
their attachments, but also on tendinous
connections to the papillary muscles of the
ventricular wall.
Heart Pathology
• In the United States, heart disease
accounts for nearly 40% of all postnatal
deaths, totaling about 750,000 individuals
annually; this is nearly 1.5 times the
number of deaths caused by all forms of
cancer combined
• one third of Americans have one or more
types of cardiovascular disease
HEART DISEASE
•CONGENITAL (CHD)
•
•
•
•
ISCHEMIC (IHD)
HYPERTENSIVE (HHD)
VALVULAR (VHD)
MYOPATHIC (MHD)
INTENDED LEARNING OUTCOMES
CONGENITAL (CHD):
1. To know Cardiac Development
2. To know causes of CHD
3. Pathophysiology and clinical presentations of:
•
ASD, VSD, patent ductus arteriosus (PDA)
•
Tetralogy of Fallot
•
Transposition of the great arteries
•
Persistent Truncus arteriosus
•
Tricuspid atresia
•
Total anomalous pulmonary venous connection
•
COARCTATION of aorta
•
pulmonary stenosis/atresia
•
Aortic stenosis/atresia
CONGENITAL HEART
DEFECTS
• Faulty embryogenesis (week 3-8)
• Usually MONO-morphic (i.e., SINGLE lesion)
• Approximately half of congenital
cardiovascular malformations are
diagnosed in the first year of life
• May not be evident until adult life (Coarctation,
ASD)
• Overall incidence 1% of USA births
• Most defects are sporadic, but there are some
genetic syndromes associated with congenital
heart disease
Most Common CHD in US
Incidence per Million Live
Births
%
4482
42
2. Atrial septal defect
1043
10
3. Pulmonary stenosis
Patent ductus arteriosus
836
8
781
7
Tetralogy of Fallot
577
5
Coarctation of aorta
Atrioventricular septal defect
Aortic stenosis
Transposition of great arteries
Truncus arteriosus
Total anomalous pulmonary venous
connection
Tricuspid atresia
492
5
396
4
388
4
388
4
136
1
120
1
Malformation
1.Ventricular septal defect
<1
Cardiac Development
1. Day 15: heart cell precursors of mesoderm
moving to the mid-line in two migratory waves
to create a crescent of cells consisting of the
first and second heart fields
2. Day 20 (Week3), the initial cell crescent
develops into a beating tube
Cardiac Development
3. Day 28 (WEEK4) beginning formation of heart
chambers, rightward looping of the heart tube, cardiac
neural crest cells (blue) migrate (arrow) into the
outflow tract and pattern the bilaterally symmetric
aortic arch arteries
4. Day 50 (WEEK 7) Septation of the ventricles, atria,
and atrioventricular valves (AVV) results in the
appropriately configured four-chambered heart
GENETICS of CHD
1. Most common genetic cause of congenital heart
disease is trisomy 21 (Down syndrome)
2. Trisomy 13, 15, 18 or Turner (XO) – Coarctation
of Aorta!
3. 22q11.2 deletion (DiGeorge syndrome aka
CATCH22)Tetralogy of Fallot, aortic arch
abnormalities
4. Marfan Syndrome – cystic medial degeneration
of aorta – aortic aneurism
5. Tuberous Sclerosis (mutation of tumor
suppressor genes TSC) – valvular obstructions
due to cardiac rhabdomyomas in newborns
6. Friderich Ataxia – Hypertrophic cardiomyopathy
Father has VSD – for child risk is 2%
Mother has VSD – for child risk 6-10%
ENVIRONMENT
1. RUBELLA
2. TERATOGENS
3. gestational diabetes
4. Folic acid deficiency
CHD CLASSIFICATION
I. A shunt is an abnormal communication between
chambers or blood vessels
• LR SHUNTS: all “D’s” in their names (ASD, VSD,
ASVD, and patent ductus arteriosus- PDA )
– NO cyanosis
– Pulmonary hypertension present
– Prolonged pulmonary hypertension is IRREVERSIBLE
• RL SHUNTS: all “T’s” in their names (Tetralogy
of Fallot, Transposition of the great arteries,
persistent Truncus arteriosus, Tricuspid atresia,
Total anomalous pulmonary venous connection)
– CYANOSIS (i,.e., “blue” babies)
– VENOUS EMBOLI become SYSTEMIC
II. OBSTRUCTIONS (coarctation of the aorta, aortic
valvular stenosis, pulmonary valvular stenosis )
Septum Primum
Septum Secundum
Ventricular Septum
Septum primum
migrates down
Septum
Secundum
migrates up
Ventricular
Septum
migrates up
Formation of Atrial and Ventricular defects
ASD
• Abnormal, fixed opening in the
atrial septum caused by
incomplete tissue formation that
allows communication of blood
between the left and right atria
• Usually asymptomatic until
adulthood
3 Main Types:
• SECUNDUM (90%): Defective
fossa ovalis (B, E)
• PRIMUM (5%): Next to AV valves,
mitral cleft defect –it associated
with Down Syndrome!!! (D)
• SINUS VENOSUS (5%): Next to
SVC with anomalous pulmonary
veins draining to SVC or IVC (A
and C)
Patent foramen ovale
• A small hole created by an open flap
of tissue in the atrial septum at the
oval fossa.
• Normally, foramen ovale is an
important functional right-to-left shunt
that allows oxygen-rich blood from the
placenta to bypass the not yet inflated
lungs
• The hole is forced shut at birth in 80%
of cases
• Sustained pulmonary hypertension or
even transient increases in right-sided
pressures, such as occurs during a
bowel movement, coughing, or
sneezing, can produce brief periods of
right-to-left shunting, with the
possibility of paradoxical embolism
ASD Clinical Features
• Splitting of S1 and S2 sounds, crescendodecrescendo systolic murmur in the second
intercostal space at the upper left sternal border.
• Paradoxal embolism (emboli from veins in systemic
arteries)
• ASDs do not become symptomatic before age 30
(why?)
• Irreversible pulmonary hypertension is unusual, but
LARGE defects may progress to pulmonary
hypertension and reverse of the shunt which will
lead to cyanosis (aka Eisenmenger syndrome)
ASD treatment and prognosis
• Surgical or catheter-based closure of an
ASD reverses the hemodynamic
abnormalities and prevents complications,
including heart failure, paradoxical
embolization, and irreversible pulmonary
vascular disease.
• Long-term survival is comparable to that of
a normal population
VSD
•
•
•
•
Most common CHD
defect
Incomplete closure of the
ventricular septum
Only 30% are isolated
(Often associated with
TETRALOGY of FALLOT)
MC Associated with fetal
alcohol syndrome
VSD Morphology
• 90% involve the membranous
septum
• Infundibular VSD - below the
pulmonary valve
• Muscular septum VSD, likely to
have multiple holes (“Swisscheese” septum )
• SMALL ones often close
spontaneously
• LARGE ones progress to
pulmonary hypertension and
reverse of the shunt which will
lead to cyanosis (aka
Eisenmenger syndrome)
Infundibular VSD - below the pulmonary valve
Clinical presentation of VSD
• Low Pitched HoloSystolic murmur,
accentuation with handgrip exercise
• Splitting of S2
• Polycythemia
• Clubbing of digits
• Paradoxal embolization
• Rx: Surgical closure
• A 7-year old boy is brought to the pediatrician by
his mother for a routine check-up. He has no
complains. Cardiac auscultation findings at the
left sternal border are given below. The findings
accentuate with the handgrip exercise Which of
The following is the most likely diagnosis?
• A Atrial septal defect
• B. Hypertrophic cardiomyopathy
• C. Patent ductus arteriousus
• D. Ventricular septal defect
• E. Aortic regurgitation
Physiologic ways to increase intensivity of
murmurs
PDA (Persistent ductus arteriosus)
• DA should be closed within 1224hrs after birth
• 90% of PDAs isolated
• 10% associated with VSD, or
coarctation of the aorta, or
pulmonary or aortic valve
stenosis
• Associated with congenital
rubella
• PGE kEEps PDA open
• At the beginning is left to right shunt
but later is switched to right to left
(Eisenmenger syndrome)
PDA
Clinic
• HOLOSYSTOLIC HARSH, machinerylike murmur
• LR, possibly RL as pulmonary
hypertension approaches systemic
pressure with development of cyanosis
• Closing the defect may be life saving
• Indomethacin causes closure of PDA
• A 10-year-old immigrant from Eastern Europe is
brought to the physician because of exertional
dyspnea and easy fatigability. According to his
parents, he was diagnosed with a congenital heart
disease in infancy for which they refused treatment.
They cannot recall the details of his diagnosis.
Physical examination reveals toe cyanosis and
clubbing but no finger abnormalities. This patient
most likely suffers from which of the following?
• A. Primum-type atrial septal defect
• B. Secundum-type atrial septal defect
• C. Ventricular septal defect
• D. Patent ductus arteriosus
• E. Coarctation of the aorta
• F. Tetralogy of Fallot
AVSD
• Associated with
defective, inadequate
AV valves
• The two most common
forms are partial AVSD
(consisting of a primum
ASD and a cleft anterior
mitral leaflet, causing
mitral insufficiency) and
complete AVSD (a hole
in the center of the
heart).
• More that 1/3 of all
patients with a complete
AVSD have Down
syndrome.
• Rx: surgery
RL SHUNT – 5Ts
1. Tetralogy of Fallot
2. Transposition of great arteries
3. Truncus arteriosus
4. Total anomalous pulmonary venous
connection
5. Tricuspid atresia
RL SHUNTS
• TETRALOGY of FALLOT most COMMON
– 1) LARGE Ventricular Septal Defect
– 2) OBSTRUCTION to blood flow from RV
into Pulmonary artery
– 3) Aorta OVERRIDES the VSD
– 4) Right Ventricular Hypertrophy
– SURVIVAL DEPENDS on SEVERITY of
SUBPULMONIC STENOSIS
– Can be a “PINK” tetrology if pulmonic
obstruction is small, but the greater the
obstruction, the greater is the RL shunt
CLASSICAL “TETROLOGY” of FALLOT
1) VSD, large
2) OBSTRUCTION to RV flow
3) Aorta OVERRIDES the VSD
4) RVH (not shown on this
picture)
10% alive at 20
years and 3% at 40
years
Clinical Features:
Clinical features
• Physical exercises cause
cyanosis in this patients
(cyanotic spells)
• Squatting alleviate
cyanosis !!!
• Degree of pulmonic
stenosis determines extent
of shunting and cyanosis
• CXR – boot shaped heart
• Auscultation: diamond
shaped systolic murmur
• A 2-week-old girl is found to have a harsh
murmur along the left sternal border. The
parents report that the baby gets “blu-ish” when
she cries or drinks from her bottle.
Echocardiogram reveals a congenital heart
defect associated with pulmonary stenosis,
ventricular septal defect, dextroposition of the
aorta, and right ventricular hypertrophy.
What is the appropriate diagnosis?
(A) Atrial septal defect
(B) Coarctation of aorta, postductal
(C) Coarctation of aorta, preductal
(D) Tetralogy of Fallot
(E) Truncus arteriosus
TGA (TRANSPOSITION
of GREAT ARTERIES)
Creates two not linked
circuits:
•PA arises from LV
•Aorta arises from RV
NEEDS a SHUNT for survival
–PDA or PFO (65%), “unstable”
shunt
–VSD (35%), “stable” shunt
Q:What will happen if we close
PDA in patient with TGA?
A:
TGA Clincal Features
– Associated with maternal
diabetes
– RV>LV in thickness
– Need to administer PgE to
keep PDA open until surgery
– Fatal in first few months if not
corrected
Rx:
- Prostaglandin E
- Surgical “switching”
– Balloon Septostomy
Possible USMLE Scenario
• A 27-year-old woman gives birth to a term infant after an
uncomplicated pregnancy and delivery. The infant is
cyanotic at birth. Two months later, physical examination
shows the infant to be at the 37th percentile for height and
weight. The representative gross appearance of the infant's
heart is shown in figure. What is the most likely diagnosis?
(A) Tetralogy of Fallot
(B) Pulmonic stenosis
(C) Truncus arteriosus
(D) Transposition of the great vessels
(E) Aortic stenosis
PERSISTENT TRUNCUS
ARTERIOSUS
1. Single large vessel
arising from both
ventricles!!!
2. Developmental failure of
separation of the
embryologic truncus
arteriosus into the aorta
and pulmonary artery
3. Cyanosis
4. Danger of irreversible
pulmonary hypertension
Early diastolic decrescendo
murmur
A 2-week-old boy is irritable and feeding poorly. On
physical examination, the infant is irritable,
diaphoretic, tachypneic, and tachycardic. There is
circumoral cyanosis, which is not alleviated by
nasal oxygen. A systolic thrill and holosystolic
murmur are heard along the left sternal border. An
echocardiogram reveals a heart defect in which the
aorta and pulmonary artery form a single vessel
that overrides a ventricular septal defect. What is
the appropriate diagnosis?
(A) Atrial septal defect
(B) Coarctation of aorta, preductal
(C) Patent ductus arteriosus
(D) Tetralogy of Fallot
(E) Truncus arteriosus
TRICUSPID ATRESIA
• Tricuspid valve
orifice fails to form
• Hypoplastic RV
• Needs a shunt,
ASD, VSD, or PDA
Signs:
• Soft S1 sound
• Low PCWP (wedge
pressure)
• RA hypertrophy –
dilation of P wave on
ECG
•Early Cyanosis and high mortality in first week
Main message:
• pulmonary atresia, tricuspid atresia,
Tetralogy of Fallot, Transposition of the
great vessels – administer prostaglandin
to keep DA open or child will die!
Total Anomalous Pulmonary
Venous Connection (TAPVC)
• PULMONARY
VEINS do NOT go
into LA, but into L.
innominate v. or
coronary sinus
• Needs a PFO or a
VSD
• HYPOPLASTIC LA
• Do not administer
Prostaglandin E1
OBSTRUCTIVE CHD
• COARCTATION of aorta
• Pulmonary stenosis/atresia
• Aortic stenosis/atresia
COARCTATION of AORTA
• Coarctation=narrowing of
aorta
• Two major forms:
INFANTILE and ADULT
(pre- and postductal)
• “Infantile” form:
hypoplasia of the aortic
arch proximal to a patent
ductus arteriosus
• symptomatic in early
childhood
Infantile form (preductal) COARCTATION
of AORTA
• Associated with presence of patent ductus
arteriosus
• Presents with lower part of the body
cyanosis, upper extremities are ok
• XO’s (Turner syndrome) frequently
have it with shortening of 4th
metacarpal bone and horse-shoe
kidney!!!
Adult form of COARCTATION of AORTA
• Discrete ridgelike infolding of
the aorta, just opposite the
closed ductus arteriosus
(ligamentum arteriosum)
distal to the arch vessels
• Bicuspid aortic valve 50% of
the time (prone to aortic
stenosis)
• Associated with congenital
aortic stenosis, ASD, VSD,
mitral regurgitation, or berry
aneurysms of the circle of
Willis in the brain
Clinical manifestations Adult form of
COARCTATION of AORTA
• Hypertension in the upper
extremities
• Development of collateral
circulation between the
precoarctation arterial
branches and the
postcoarctation arteries
through enlarged intercostal
and internal mammary arteries,
which produce radiographically
visible erosions (“notching”) of
the undersurfaces of the ribs
• Murmurs are present
throughout systole, ;
sometimes a thrill
• Cardiomegaly due to left
ventricular pressure-overload
hypertrophy
Prognosis for Adult form of
COARCTATION of AORTA
Patients with adult-type coarctation of the
aorta commonly die of hypertensionassociated complications:
left ventricular failure
ruptured dissecting aortic aneurysm
intracranial hemorrhage (due to the
increased incidence of congenital berry
aneurysms of the Circle of Willis)
• A 22-year-old Caucasian male presents to the
emergency room complaining of severe headaches
and vomiting. Soon after, he slips into a coma and
dies. Autopsy shows a ruptured cerebral aneurysm
with extensive intracranial hemorrhage. This patients
condition is most likely associated with:
A. Primum-type atrial septal defect
B. Secundum-type atrial septal defect
C. Ventricular septal defect
D. Patent ductus artenosus
E. Coarctation of the aorta
F. Tetralogy of Fallot
Pulmonary Valve Stenosis and Atresia
• PS- an obstruction at the
pulmonary valve
• Lesion can be isolated or part of
a more complex anomaly—either
tetralogy of Fallot or
transposition of the great arteries
• Right ventricular hypertrophy is
often
• Poststenotic dilation of the
pulmonary artery due to injury of
the wall by “jetting” blood.
• When the valve is entirely atretic,
there is an ASD and blood
reaches the lungs through a
patent ductus arteriosus.
• Clinical severity ~ stenosis
severity
•
•
•
•
•
•
AORTIC VALVE
STENOSIS/ATRESIA
Stenosis - Three locations:
valvular,
subvalvular,
supravalvular
Atresia leads to underdevelopment
(hypoplasia) of the left ventricle and
ascending aorta, sometimes accompanied by
dense, porcelain-like left ventricular
endocardial fibroelastosis
The ductus arteriosus is open to allow blood
flow to the aorta and coronary arteries
• when the ductus will be closed it
will lead to the child death
•
•
Less severe degrees of congenital aortic
stenosis may be compatible with long
survival
Congenital aortic stenosis is an isolated
lesion in 80% of cases.
MITRAL VALVE PROLAPSE:
CLINICAL FEATURES
• displacement of an abnormally
thickened mitral valve leaflet
into the left atrium during
systole
• Usually asymptomatic
• Mid-systolic “click”
• Holosystolic murmur if
regurg. present
• Occasional chest pain,
dyspnea
• 97% NO untoward effects
• 3% Infective endocarditis,
mitral insufficiency,
arrythmias, sudden death
Ebstein anomaly
• Congenital heart defect in
which the septal leaflet of
the tricuspid valve is
displaced towards the
apex of the right
ventricle of the heart
• Etiology: Fetal exposure
to Lithium !!!!
• Systolic murmur
of tricuspid regurgitation
• Mid-diastolic murmur
along the lower left
sternal border
• Right atrial hypertrophy
• WPW syndrome on ECG