Congenital Heart Disease -...

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


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


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


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)


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


Minor right ventricular conduction delay (ICRBBB: an rsR' pattern in the right precordial leads)

Enlargement of the LV in Ostium Primum Defect

Echocardiography


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



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


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


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


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


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


Differential Cyanosis



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


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


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


Small PDA: PAP, RVP and RAP are normal

Large PDA: PAP may be elevated to systemic levels

during both systole and diastole


According to the size of the ductus:

Small PDA: Asymptomatic

Large PDA: poor feeding and retardation of

physical growth, sometimes with hoarseness


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


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


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


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

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


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



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


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



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.


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

谢谢 Thank You

Congenital Heart Disease -...

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