congenital heart disease -...
TRANSCRIPT
Congenital Heart Disease
Children’s Hospital Zhejiang University School of Medicine
Cardiovascular Development
Key periods:the 2nd ~8th weeks
Fetal Circulation
Physiological Changes in the Circulation After Birth
Changes in the pulmonary circulation
Closure of the ductus arteriosus
Closure of foramen ovale
Arrest of circulation through the placenta
Epidemiology of Congenital Heart Disease
Congenital heart disease occurs in approximately 8 of 1000 live births
About 2-3 out of 1000 total newborn infants will be symptomatic with heart disease in the 1st yr of life
Etiology
The etiology of most specific congenital heart defects is still unknown
Genetic Factors:
(1) single gene mutation or multifactorial inheritance pattern
(2) certain types of VSD (supracristal) are more common in
children of Asian background
(3) the recurrence risk of congenital heart disease increases
from 0.8% to about 2-6% if a 1st degree relative is affected.
(4) approximately 3% of patients with congenital heart disease
have an identifiable single gene defect, such as Marfan or
Noonan syndrome
(5) 5-8% of patients with congenital heart disease have an
associated chromosomal abnormality: 90% of trisomy 18,
50% of trisomy 21, 40% of Turner syndrome
Infective Factors:
congenital rubella syndrome
Environmental Factors:
physical and chemical factors
Drug Factors
Maternal Diseases:
Diabetes mellitus, SLE
Classification of Congenital Heart Disease Left to right Shunt Lesions:
potential cyanotic CHD (ASD, VSD, PDA)
Right to Left Shunt Lesions:
cyanotic CHD (TOF, TGA)
No Shunt Lesions:
acyanotic CHD (PS, AS, COA, MS, MVP)
The Common Features of Left to Right Shunt CHD Potential cyanosis
Systolic heart murmur in left sternal
border (LSB)
Pulmonary blood flow increase
Systemic blood flow decrease
Diagnostic Methods History and Physical Examination
ECG
Chest X-ray
Echocardiography
M-mode, two dimension --- morphology
Pulsed, continuous wave and colour doppler
Transesophageal Echocardiography (TEE)
Fetal Echocardiography
Catheterization
pressure, resistance, oxygen saturation, cardiac output,
pathway, angiocardiography, myocardial biopsy,
electrophysiologic study, interventional treatment
MRI, CT, ECT
Treatment in Patients with CHD
Non-operation
Drug: PGE1, Indomethacin
Interventional treatment
Operation
Atrial Septal Defect
(ASD)
Development of Atrial Septum
Classification of ASD
Ostium Primum Defect (AV Canal or Endocardial Cushion or Atrioventricular
septal defect) In the lower portion of the atrial septum and
overlies the mitral and tricuspid valves, common with a cleft in
the anterior leaflet of mitral valve and mitral regurgitation
Ostium Secundum Defect
Sinus Venosus Defect
Patent foramen ovale Isolated patent foramen ovale is
usually of no hemodynamic significance
Type of Secundum ASD
Pathophysiology of ASD
Pathophysiology of ASD
SVC IVC LV↓ LA RA↑↑ RV↑↑ AO↓ PV PA ↑↑ Hyperkinetic pulmonary hypertension extremely large pulmonary blood flow Obstructive pulmonary hypertension pulmonary arteriolar medial thickness pulmonary vascular obstructive disease RVP↑ RAP↑ RAP≥LAP RA to LA Shunt cyanosis-- Eisenmenger syndrome
ASD
comparative pulmonary valve stenosis
Pathophysiology of ASD
Left to right shunt can occur both in systole and diastole
because the LA pressure is always little higher than the RA
pressure both in systole and diastole
The degree of Left-to-Right shunting is dependent on:
1. size of defect
2. relative compliances of the RV and LV
3. relative vascular resistances in the pulmonary
and systemic circulations
Pathophysiology of ASD
The large blood flow through the right side of the heart results in:
l. enlargement of RA and RV and dilatation of PA
2. the pulmonary artery pressure (PAP) remains normal because of
the absence of a high pressure communication between the
pulmonary and systemic circulations
3. pulmonary vascular resistance remains low throughout childhood,
but it may begin to increase in adulthood
4. the LV is normal in size
Clinical Manifestations
Asymptomatic
A soft systolic murmur at the 2nd intercostal
space of LSB (increased RV blood flow across the
pulmonary valve---comparative pulmonary valve stenosis)
Typical wide and fixed splitting of P2 (The pulmonic
2nd heart sound) throughout the respiratory cycle ( increased RV blood flow producing a prolonged pulmonary
valve close constantly throughout the respiratory cycle)
Clinical Manifestations
An early-to-mid diastolic murmur at the lower LSB (increased blood flow across the tricuspid valve---- comparative
tricuspid valve stenosis)
P2 louder and pulmonic ejection click when
pulmonary hypertension
Chest X-ray
Enlargement of the RA and RV
Pulmonary artery is large
Pulmonary vascularity is increased
LV is normal
Enlargement of the LV in Ostium Primum Defect
ECG
Right axis deviation
Enlargement of the RA and RV
Minor right ventricular conduction delay (ICRBBB: an rsR' pattern in the right precordial leads)
Enlargement of the LV in Ostium Primum Defect
Echocardiography
Enlargement of the RA and RV
Ventricular septum and posterior wall of LV move in
same direction
Position and size of ASD
Direction and degree of
shunt in ASD
Catheterization
• Oxygen saturation in RA is higher
than in SVC and IVC
• Right cardiac catheter is easy to enter
LA through the ASD
Prognosis and Complications
symptoms usually do not appear until the
3rd decade or later
pulmonary hypertension and heart failure
are late manifestations
infective endocarditis is extremely rare
Treatment
Surgery is advised for all symptomatic
patients and also for asymptomatic
patients with a shunt ratio of at least 2 : l
The timing for elective closure is usually
at some time prior to entry school
Occlusion devices implanted by
interventional cardiac catheterization
ASD封堵器
Interventional Treatment
Ventricular Septal Defect
(VSD)
The most common cardiac malformation
accounting for 25 - 50% of CHD
Classification of VSD
Membranous VSD most common defect
Outlet (supracristal, infundibular, subpulmonary) VSD situated just beneath the pulmonary valve
Inlet VSD
Muscular VSD
AO↓ LV↑↑ RVH PA ↑↑ LA↑↑ PV Hyperkinetic pulmonary hypertension extremely large pulmonary blood flow Obstructive pulmonary hypertension pulmonary arteriolar medial thickness pulmonary vascular obstructive disease RVP↑ RVP≥LVP RV to LV Shunt cyanosis-- Eisenmenger syndrome
VSD
Pathophysiology of VSD
Pathophysiology of VSD
The degree of Left-to-Right shunting is dependent on:
1. size of defect
2. pulmonary and systemic vascular resistances
Left to right shunt is only in systole because the LV
pressure is higher than the RV pressure in systole,
and the both pressure is equal in diastole
Pathophysiology of VSD
The large blood flow through the VSD results in:
l. Enlargement of LV and LA (volume overload), dilatation of PA,
enlargement of RV when pulmonary hypertension
2. Pulmonary hypertension:
early: extremely large pulmonary blood flow — Hyperkinetic
pulmonary hypertension
late: pulmonary arteriolar medial thickness and pulmonary vascular
obstructive disease — Obstructive pulmonary hypertension
When the ratio of pulmonary to systemic resistance approaches 1:1, the shunt become bidirectional, signs of heart failure abate, and the patient becomes cyanosis ---- Eisenmenger syndrome
Clinical Manifestations
according to the size of defect and
the pulmonary blood and pressure
Small VSD
Asymptomatic
A loud, harsh, or blowing holosystolic murmur at the 3rd - 4th
intercostal space of LSB with thrill
Chest X-ray: normal or minimal cardiomegaly and a borderline
increase in pulmonary vasculature
ECG: normal or left ventricular hypertrophy
Large VSD
Dyspnea, feeding difficulties, poor growth, profuse perspiration, recurrent pulmonary infections and cardiac failure in early infancy
Prominence of the left precordium and sternum, parasternal lift and systolic thrill
A loud, harsh, or blowing holosystolic murmur at the 3rd - 4th intercostal space of LSB
P2 louder when pulmonary hypertension
Mid-diastolic, low-pitched rumble at the apex: increased blood flow across the mitral valve
Large VSD
Chest X-ray: Gross cardiomegaly with prominence of
LV, RV, LA and PA
Pulmonary vascular markings increase
and frank pulmonary edema may be
present
Aortic knob is small
ECG: Biventricular hypertrophy, P waves may be notched or peaked
Echocardiography
Enlargement of the LA and LV, and RV and PA in patients with pulmonary hypertension
Position and size of VSD
Direction and degree of shunt in VSD
Catheterization
Oxygen saturation in RV is higher than in RA
RV and PA pressure are normal or increase
Right cardiac catheter can enter LV and
Aorta through defect in some very large VSD
patients
Prognosis
The natural course of VSD depends to a large degree on
the size of the defect
30-50% of small perimembranous and muscular VSD will close
spontaneously, most frequently during the 1st yr of life. The vast
majority of defects that close will do so before age 4~5 yr. It is less
common for moderate or large defects to close spontaneously. Outlet VSD
is no possible to close spontaneously
Complications
The large VSD: repeated episodes of respiratory
infection, congestive heart failure (CHF) and
failure to thrive, and pulmonary hypertension
Infective endocarditis
Treatment
Small VSD does not need restrictions of physical
activity and surgery repair. These patients can be
followed by a combination of clinical examinations
and noninvasive laboratory tests until the defects
has closed spontaneously
Large and outlet VSD needs medical management to
control CHF and to prevent the development of
pulmonary vascular disease, and surgery repair early
in patients with pulmonary hypertension
肌部VSD 封堵器
Interventional Treatment
Interventional Treatment
Patent Ductus Arteriosus (PDA)
During fetal life, most of the
pulmonary arterial blood is
shunted through the ductus
arteriosus into the aorta.
Functional closure of the
ductus normally occurs soon
after birth
The aortic end of the ductus
is just distal to the origin of
the left subclavian artery,
and the ductus enters the
pulmonary artery at its
bifurcation
Figure of PDA
AO PA↑↑ PV LV↑↑ LA↑↑ Hyperkinetic pulmonary hypertension extremely large pulmonary blood flow Obstructive pulmonary hypertension pulmonary arteriolar medial thickness pulmonary vascular obstructive disease PAP≥AOP RVP↑↑ RVH PA to AO Shunt Low extremity cyanosis (differential cyanosis)--- Eisenmenger syndrome
PDA
Pathophysiology of PDA
Pathophysiology of PDA
Differential Cyanosis
Pathophysiology of PDA
The degree of Left-to-Right shunting is dependent on:
1. the size of the ductus
2. ratio of pulmonary and systemic vascular resistances
Left to right shunt can occur both in systole and diastole
because the aortic pressure is always higher than the
pulmonary arterial pressure both in systole and diastole
Pathophysiology of PDA
The large blood flow through the PDA results in:
1. enlargement of LV and LA (volume overload), dilatation of PA,
enlargement of RV when pulmonary hypertension
2. pulmonary hypertension:
early: extremely large pulmonary blood flow --- Hyperkinetic
pulmonary hypertension
late: pulmonary arteriolar medial thickness and pulmonary vascular
obstructive disease --- Obstructive pulmonary hypertension
3. when the ratio of pulmonary to systemic resistance approaches 1:1,
the shunt becomes bidirectional, signs of heart failure abate, and
the patient becomes cyanosis (differential cyanosis) ---
Eisenmenger syndrome
Pathophysiology of PDA
Small PDA: PAP, RVP and RAP are normal
Large PDA: PAP may be elevated to systemic levels
during both systole and diastole
Clinical Manifestations
According to the size of the ductus:
Small PDA: Asymptomatic
Large PDA: poor feeding and retardation of
physical growth, sometimes with hoarseness
Clinical Manifestations
Prominence of the left precordium and apical impulse in large PDA
Wide pulse pressure (≥40 mmHg) and bounding arterial pulse: peripheral blood vessel sign due to runoff of blood into pulmonary artery during diastole
Thrill, maximal in the 2nd left intercostal space, may radiate toward the left clavicle, down LSB or toward apex, usually in systole, but also may be throughout the cardiac cycle
Clinical Manifestations
Classic murmur:
1. Continuous, machinery and rolling thunder murmur
2. Begining soon after onset of the 1st sound, reaches maximal
intensity at the end of systole, and wanes in late diastole
3. Located at the 2nd left intercostal space and radiate down the
LSB or to left clavicle
4. When pulmonary vascular resistance increases or heart failure,
the diastolic component of the murmur may be less prominent or
absent
Chest X-ray
Prominent pulmonary artery with increased intrapulmonary
vascular markings
Normal or minimal cardiomegaly in small PDA and marked
cardiomegaly in large PDA. The chambers involved are LA and
LV, and RV when pulmonary hypertension
Aortic knob is prominent
ECG
normal in small PDA
left ventricular or biventricular hypertrophy in large PDA
Echocardiography
enlargement of the LA and LV, and RV and PA in patients with
pulmonary hypertension
position, shape and size of PDA
direction and degree of shunt in PDA
Catheterization
1. Oxygen saturation in PA is higher than in RV
2. RV and PA pressure are normal or increase
3. Right cardiac catheter can enter descending
aorta through PDA in most of patients
4. Angiocardiography is needed in some patients
with very tiny PDA
Prognosis and Complications
The patients with a small PDA may live a normal span with few or
no cardiac symptoms
Spontaneous closure of the ductus after infancy is extremely rare
The repeated episodes of respiratory infection, congestive heart
failure, failure to thrive and pulmonary hypertension are common in
large PDA
Infective endocarditis may be seen at any age, pulmonary and
systemic emboli may occur
Aneurysmal dilatation of the pulmonary artery or the ductus
Treatment
PDA in premature infant: indomethacin
Irrespective of age, patients with PDA require
treatment (including surgical and interventional closure)
in order to prevent infective endocarditis, congestive
heart failure and the development of pulmonary
vascular disease
Interventional Treatment
Those patients with left to right shunt (VSD, PDA, ASD, et)
whose shunts have become partially or totally right to left as
a result of the development of pulmonary vascular disease
所有左向右分流的先天性心脏病(ASD、VSD、PDA 等)由于器质性肺血管病变导致梗阻性肺动脉高压,右心系统压力等于或超过左心系统,出现双向或右向左分流
Eisenmenger syndrome 艾森曼格综合征
Tetralogy of Fallot
(TOF)
Pathophysiology Obstruction to right ventricular
outflow tract (infundibular
stenosis) -- the most important
malformation (sometimes with
pulmonary valve and artery
stenosis)
Ventricular septal defect large
and nonrestrictive VSD just
below the aortic valve
Override of the aorta
(dextroposition of the aorta in
25% patients)
Right ventricular hypertrophy
Pathophysiology
The degree of right ventricular outflow obstruction
determines the timing of onset of symptoms, the severity of cyanosis, and the degree of right ventricular hypertrophy
The degree of right ventricular outflow obstruction and override of the aorta can become more and more severe with growth
Obstruction to right ventricular outflow tract Spasm of Stenotic Infundibulum Hypoxic Spells RVP↑↑ RVP≥LVP Pulmonary Blood Flow↓↓ Collateral Artery From DAO RVH Override of the aorta RV to LV Shunt Gas Exchange in Lung ↓↓ AO Blood from LV and RV Artery Oxygen Saturation ↓ Cyanosis Polycythemia Clubbing Squatting
Cerebral thromboses Brain abscess
VSD
Pathophysiology of TOF
Clinical Manifestations
Cyanosis
Often is not present at birth, but with increasing
hypertrophy of the RV infundibulum and growth, cyanosis occurs later in the 1st yr of life
It is most prominent in the mucous membranes of the lips and mouth, and in the fingernails and toenails
In infants with severe RV outflow obstruction, cyanosis is noted immediately in the neonatal period
Paroxysmal hypercyanotic attacks (hypoxic spells) 1. Spasm of stenotic infundibulum → pulmonary blood
flow ↓↓→ most of all RV blood into aorta → severe
systemic hypoxia and metabolic acidosis
2. A particular problem during the first 2 yr of life
3. Hyperpneic, restless, cyanosis increases, gasping
respirations ensue and syncope
Clinical Manifestations
Clinical Manifestations
4. Frequently in the morning upon first awakening or following episodes of vigorous crying
5. Temporary disappearance or decrease in intensity of the systolic murmur due to the decrease of flow across the RV outflow tract
6. Last a few minutes or hours, rarely fatal. Followed by generalized weakness and sleep. Sevre spells may progress to anconsciousness and mnvulsions or hemiparesi
Clinical Manifestations
Clubbing of fingers and toes Dyspnea and Squatting l. Squatting → systemic artery pressure and resistance
increase → LVP increase
2. Squatting → venous return decrease → RVP decrease
l, 2 → Right to left shunt decrease through VSD
and hypoxia can be improved
Growth and development may be delayed
in patients with severe untreated tetralogy of Fallot
Left anterior hemithorax may bulge anteriorly due to
RV hypertrophy
Substernal right ventricular impulse
Systolic thrill in the 3rd and 4th parasternal spaces
along LSB in 50% cases
Clinical Manifestations
Clinical Manifestations
Systolic Murmur
1. ejection or holosystolic, loud and harsh
2. most intense in the 2nd -4th intercostal space of LSB
3. caused by turbulence through the RV outflow tract due to the infundibular stenosis
The 2nd heart sound is single or the pulmonic component is soft
Chest X-ray
Narrow base, concavity of pulmonary artery and normal heart size
Rounded apical shadow above the diaphragm than normal
Pulmonary vascular marking decrease
Large aorta and 25% cases with dextroposition of aortic arch
Cardiac silhouette ----- boot or wooden shoe
ECG
Right axis deviation and RVH
Echocardiography
The aorta widen and override on the large ventricular septal defect
Obstruction to right ventricular outflow tract (infundibular stenosis)
Right ventricular hypertrophy
Left ventricular is small
Cardiac Catheterization and Angiocardiography
RVP increases and equals
to the LVP
Oxygen saturation in Ao and
LV decreases
Angiocardiography in RV
and LV can show the
position and size of VSD,
size of LV , width and
overriding degree of aorta,and degree of obstruction of
RVOT, et.
Prognosis and Complications
Cerebral thromboses
1. usually in cerebral veins, occasionally in cerebral arteries
2. common in the presence of extreme polycythemia and
dehydration under the age of 2 yr
Brain abscess usually over the age of 2 yr
Bacterial endocarditis
Congestive heart failare unusually in TOF
Treatment of hypoxic spells Depending on the frequency and severity of hypercyanotic attacks, one
or more of the following procedures should be instituted in sequence:
1. Knee-chest position
2. Administration of oxygen
3. injection of morphine subcutaneously in a dose not in excess of 0.2 mg/kg
4. Correction of metabolic acidosis with intravenous administration of sodium
bicarbonate if the spell is unusually severe and there is lack of response
to the foregoing therapy
5. β- Adrenergic blockade by intravenous administration of propranolol (0.1
to a maximum of 0.2 mg/kg)
6. Drugs that increase systemic vascular resistance, such as intravenous
methoxamine or phenylephrine, decrease the right-to-left shunt
Treatment of TOF
Depend on the severity of the RVOT obstruction
palliative surgery
total correction
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