Congenital Heart Disease - ibrahimhajjali.weebly.com · Dysmorphic features that may indicate a...

CONGENITAL HEART DISEASE

A SIMPLIFIED LOOK

Jennifer Fung, James Gray, Ibrahim Hajjali

Overview

Embryologic Development

Most critical period of fetal heart development is between 3-8 wks gestation

Single heart tube grows rapidly forcing it to bend back upon itself and begin to assume the shape of a four chambered heart

Insults at this time are most likely to lead to CHD

Epidemiology

8/1,000 live births can present with heart murmur, heart failure, or cyanosis

Ventricular septal defect is the most common lesion

The Basics

Embryology

Structures

Truncus Arteriosus -> Great Vessels

Bulbus Cordis -> Outflow Tracts of L and R Ventricles

Primitive Ventricle -> L and R Ventricles

Primitive Atria -> L and R Atria

Left Horn -> Coronary Sinus

Right Horn -> R atrium

Embryology

Embryology

The Septums

Aorticopulmonary Septum:

Relies on migration of neural crest cells.

Failure of migration leads to persistent Truncus Arteriosus, Tetralogy of Fallot, Transposition

Atrial Septum:

Growth of septum is guided by endocardial cushions.

Contains Foramen Ovale, an important shunt in fetal heart circulation.

Upon first breath, increased LA pressures fuse septum secundum and primum, closing the foramen.

Ventricular Septum:

Caudal 2/3 forms muscular septum from the apex.

Cranial 1/3 forms the interventricular foramen, relies on endocardialcushions to close (membranous portion of septum).

Embryology

Before Birth

Fetal lungs bypassed by flow through fetal shunts:

Shunting deoxygenated blood

Ductus arteriosus: connection between pulmonary artery and aorta

Shunting oxygenated blood

Foramen ovale: connection between R and L atria

Ductus venosus: connection between umbilical vein and IVC

Circulation:

Placenta (oxygenated blood) -> umbilical vein -> ductus venosus -> IVC -> R atrium -> oxygenated blood shunted through foramen ovale -> L atrium -> L ventricle -> aorta -> brain/myocardium/upper extremities

Deoxygenated blood returns via SVC to R atrium -> 1/3 of blood entering R atrium does not flow through foramen ovale and flows to the R ventricle -> pulmonary arteries -> ductus arteriosus -> aorta -> systemic circulation -> placenta for re-oxygenation

At Birth

With first breath, lungs open up and pulmonary resistance decreases allowing pulmonic blood flow

Increasing pulmonic flow increases left atrial pressures leading to foramen ovale closure

Increased oxygen concentration in blood after first breath leads to decreased prostaglandins leading to closure of the ductus arteriosus

Upon separation of the placenta, systemic circulation becomes a high resistance system and the ductus venosuscloses

Fetal shunts close and changes in pulmonic/systemic resistance allow for normal adult flow

Before Birth After Birth

Normal Values

Cardiac Examination

History

Start with general health issues:

Feeding difficulties, growth delay, decreased exercise tolerance.

Ask the parent to compare the child to peers of the same age to help in this assessment.

Symptoms that indicate cardiovascular disease include:

periods of cyanosis, sweating, shortness of breath, palpitations, edema, chest pain, and syncope.

Squatting after exercise can indicate a congenital cardiac defect (Tetralogy of Fallot).

Enquire about the prenatal period.

Exposure to medication or drugs: lithium, phenytoin and alcohol.

History of maternal illnesses:

SLE, Diabetes or primary rubella.

Premature births are at an increased risk of having a patent ductus arteriosus.

Don’t forget the family history.

General exam

Hand Hygeine.

Signs of Distress:

pallor, sweating, cyanosis or increased work of breathing.

Level of activity in the patient:

Do they appear comfortable? Are they interacting appropriately with you and their

parent?

Dysmorphic features that may indicate a syndrome associated with congenital heart disease

(refer to table at end).

Trisomy 21, Di George and Turner’s syndrome.

Vital signs:

HR, RR, BP, Height, Weight, and head circumference (<5 yr).

Ideally, the blood pressure should be taken in all four limbs.

Choose the proper cuff size: a small cuff will provide a falsely high blood pressure. Should

be 2/3 the length of the arm.

Be sure to plot the growth on an age appropriate chart.

Inspection

Examine the hands and feet:

Clubbing, splinter hemorrhages.

Cardiac abnormalities normally manifests as respiratory distress. Look for signs of

increased work of breathing:

Tachypnea, intercostal indrawing, tracheal tug,head bobbing and nasal flaring.

Abdominal breathing is normal in the neonate but not in the older child.

Eyes:

Scleral icterus, pallor.

Mouth:

Signs of central cyanosis, mucous membranes to assess the volume status.

JVP assessment not routinely performed if under 8 years of age.

Chest:

Shape, symmetry, precordial bulge (right-sided cardiac enlargement), skeletal

deformity (pectus carinatum or excavatum), scars.

Peripheral Palpation

Younger children may need to be examined in their parents arms, be flexible.

Capillary refill, preferably over sternum

Pulses:

Radial, brachial , femoral, dorsalis pedis, and posterior tibial

Rate, rhythm, volume, brachial-femoral delay

Precordium Palpation

Apex beat, heaves, thrills

Palpate all four auscultatory areas.

Palpation of the liver:

Indication of right-sided heart function.

normal liver may be felt up to 2 cm below the costal margin.

Assess for edema in the limbs and sacral area.

Often the best assessment of whether edema is present is by asking the child’s parent whether they think the child appears puffy.

Auscultation

Same landmarks as aduts

Be sure to listen to the back.

The murmur of aortic coarctation is sometimes only found here and will be missed if not

specifically listened for.

If a murmur is heard:

area the murmur is loudest

Timing in the cardiac cycle,

Radiation, including both the axilla and the back.

Remember that more than 50% of children will have a murmur at some point, but congenital

heart disease is present in less than 1%. Learning to distinguish pathologic from benign

murmurs is extremely important and takes practice.

Don’t forget the lungs:

Crepitations may be a late sign of pulmonary congestion secondary to congestive heart

failure.

CYANOTIC VS. ACYANOTIC

Toronto Notes, 2012. page P20

CYANOTIC VS. ACYANOTIC

Cyanotic heart disease:

cyanosis: blue mucous membranes, nail beds, and skin secondary to an absolute concentration of deoxygenated hemoglobin of at least 3 g/dL

(i.e. R to L shunt) blood bypasses the lungs -> no oxygenation occurs -> high levels of deoxygenated hemoglobin enters the systemic circulation -> cyanosis

Acyanotic heart disease:

(i.e. L to R shunt, obstruction occurring beyond lungs) blood passes through pulmonic circulation -> oxygenation takes place -> low levels of deoxygenated blood in systemic circulation -> no cyanosis

Cyanotic Congenital Heart Disease

Cyanotic Heart Disease

Some of the systemic venous return re-enters arterial circulation without re-oxygenation by the lungs

Arterial oxygen saturation <75%

“Right-to-left” shunt

Hyperoxic test helps differentiate between respiratory and cardiac causes of hypoxia

Obtain ABG on room air

Repeat ABG after 100% oxygen for 10 minutes

If PaO2 improves to >20 kPa, cyanosis less likely cardiac in origin

Survival depends on mixing via shunts (e.g. ASD, VSD, PDA)

Important to keep in mind that pressure and flow through embryological openings can keep them open after birth

Five T’s

Five cyanotic heart diseases starting with T:

Truncus arteriosus

Transposition of the great arteries

Tricuspid atresia

Tetralogy of Fallot

Total anomalous pulmonary venous return

Ebstein’s anomaly is often cyanotic

Hypoplastic left heart syndrome

Truncus arteriosus

Blood is pumped from

both ventricles into a

single trunk, which then

gives rise to the aorta

and pulmonary

arteries

VSD

Truncus arteriosus:

Presentation

Presents within the first weeks of life

Cyanosis is the first sign (often not clinically evident)

Respiratory distress appears days to weeks later (due

to pulmonary congestion and heart failure)

Ejection click and systolic ejection murmur (often

impossible to appreciate)

Usually diagnosed by echocardiography

postnatally

Sometimes detected in utero

Truncus arteriosus:

Management

Supportive medical management to stabilize for

surgical repair

Surgery is definitive

Pulmonary arteries are mobilized from the truncus and

attached to the RV

Truncus is patched

VSD is patched

Dextro-transposition of the great

arteries

Aorta arises from RV

Pulmonary trunk arises from LV

Can be associate with other anomalies (“complex TGA”)

ASD

VSD

LV outflow tract obstruction

D-TGA:

Presentation

Severity is determined by the mixing of the two

circulations and the presence of other cardiac

anomalies

The presence and size of an ASD is the most important

determinant of severity

Most present in the first 30d of life

Cyanosis (not always clinically evident)

Tachypnea without evidence of respiratory distress

D-TGA:

Diagnosis and management

Difficult to diagnose in utero

Usually diagnosed with echocardiography post-

natally

Management

Prostaglandin E1 to maintain PDA

Consider balloon atrial septostomy if severely hypoxic

Surgery: arterial switch operation

Levo-transposition of the great arteries

Tricuspid atresia

Absence of tricuspid valve

RA and RV do not communicate

ASD: R to L shunt

Usually VSD or a single hypoplasticventricle

Cyanosis in neonatal period

Tricuspid atresia:

Management

Medical:

Prostaglandin E1 to maintain PDA

Surgical:

Shunt is usally required in the first year of life

Systemic circulation to pulmonary circulation

Fontan procedure after 4y of age

Connects RA to the pulmonary arteries

Excludes RV

Close ASD

Tetralogy of Fallot

Overriding aorta

RV outflow

obstruction

VSD

Right ventricular

hypertrophy

Tetralogy of Fallot:

Presentation

Severe stenosis: a newborn with profound cyanosis

Moderate stenosis: elective evaluation for a

murmur

Mild stenosis: congestive heart failure (dyspnea on

exertion, clubbing)

“Pink variant”: rarely, the stenosis can be so mild

as to be asymptomatic for years

Tetralogy of Fallot:

Physical exam

If cyanotic, found in nailbeds and lips

Often worse while crying

Harsh, ejection systolic crescendo-decrescendo

murmur (due to right outflow obstruction)

The worse the obstruction, the quieter the murmur

“Tet spells”: severe hypercyanotic spells

Often a vicious circle of crying/anxiety which worsens

the cyanosis

Knee-to-chest position: increases SVR

Tetralogy of Fallot:

Diagnosis and management

Diagnosis:

Echocardiography is diagnostic

Boot-shaped heart on CXR

Surgical management:

Severely cyanotic newborns may require

prostaglandins to maintain a PDA

Intra-cardiac repair is gold standard (patch closure of

VSD, widening of RVOT)

Preferably within the first year of life

Total anomalous pulmonary venous

return

All four pulmonary veins fail to connect to LA

All pulmonary venous blood drains into the systemic venous system

Neonatal cyanosis (life preserved by ASD or PFO)

Surgery: connect the pulmonary veins to the LA

Ebstein’s anomaly

Malformation of the tricuspid valve and the RV (highly variable)

The tricuspid valve is partly attached the annulus and partly to the RV

The proximal RV is “atrialized” because of the large valve

The distal RV is normal

Ebstein’s anomaly

Pathogenesis is multifactorial

Occurs at increased rate with maternal lithium use

Multiple associated cardiac anomalies

ASD and PFO (80%, results in cyanosis)

VSD

Pulmonary outflow obstruction

PDA

Coarctation of the aorta

Ebstein’s anomaly:

Presentation

Highly variable and depends on degree of

displacement of the valve leaflets and their

functional status

Fetuses: abnormal scan

Neonates: cyanosis

Infants: heart failure

Children: murmur

Adolescents/adults: arrhythmia

Ebstein’s anomaly:

Diagnosis and management

Echocardiography is best for diagnosis

Medical management:

Prostaglandin E1 if severely hypoxic at birth

Arrhythmias can be managed medically but if surgery is undertaken, consider ablation or Maze procedure

Surgical management:

Tricuspid repair/replacement

Neonates: only if severely cyanotic or severe tricuspid regurg

Older patients: symptomatic, cyanosis, paradoxical embolism, progressive cardiomegaly

Hypoplastic left heart syndrome

Small left ventricle

Usually an ASD

RV is forced to supply

systemic circulation via

PDA

Fatal if untreated

(only 65% survive with

surgical repair)

HLHS:

Diagnosis and management

Diagnosis:

Early cyanosis (critically ill at birth if no ASD)

Respiratory distress

Echocardiography

Medical management:

Prostaglandin E1 to maintain PDA

Surgical management:

Complicated 3-stage procedure (neonate, 4-6mos, 18-30mos)

Does not restore a biventricular system

Acyanotic Congenital Heart Disease

Atrial Septal Defects

Atrial Septal Defect

Three types of ASD:

Secundum

Primum

Sinus Venosus

Embryology

Septation of the

atria begins in the

5th week of

gestation

The foramen

ovale in the fetus

is kept open by a

pressure gradient

Atrial Septal Defects

Symptoms and Signs

Commonly asymptomatic

Recurrent chest infections/wheeze

Heart failure

Arrhythmias

S2 heart sound (fixed and widely split)

Ejection systolic murmur heard best at upper left sternal border

Apical pansystolic murmur (seen in partial AV valve involvement)

Atrial Septal Defect

Investigations

Chest X-Ray

ECG

Echocardiogram

Atrial Septal Defect

Management

Spontaneous closure mostly likely to occur in defects <7

mm and with younger age at diagnosis

For significant, symptomatic ASDs, treatment is needed

usually between 3-5 years of age

Secundum ASDs

Cardiac catheterisation with insertion of an occlusion device

Partial AVSD

Surgical correction

Ventricular Septal Defect

Ventricular Septal Defect

Most common congenital heart defect, occurring in almost 50% of patients with congenital heart disease

Can occur with other defects, such as in the atrioventricular canal, tetralogy of Fallot, and transposition of the great arteries

VSDs can occur at any part of the interventricularseptum

Most common are membranous defects (close to the tricuspid valve)

The size of the VSD can affect the symptoms, signs, and management

Small VSDs

Clinical presentation

Usually asymptomatic

Thrill at lower sternal edge

Loud pansystolic murmur at lower left sternal edge

Quiet pulmonary second sound (P2)

Investigations

CXR and ECG normal

Echo can show the anatomical defect

Management

75% will close spontaneously within 2 years

Prevention of bacterial endocarditis with good dental hygiene

Large VSDs

Signs

Failure to thrive

Symptoms of heart failure

Cardiac murmur

Recurrent chest infections

Symptoms

Low-pitched pansystolic murmur best heard at left mid-to-lower sternal border

Apical mid-diastolic murmur

Loud P2

Large VSDs

Investigations

CXR

ECG

Echo

Management

Medical

Diuretics and ACE-

inhibitors

Surgery

Patent Ductus Arteriosus

The ductus arteriosus is a connection between the pulmonary artery to the descending aorta

A patent ductusarteriosus occurs when the connection fails to close completely after birth

Makes up 5-10% of all congenital heart defects

Patent Ductus Arteriosus

Clinical Features

Continuous machine-like murmur in the left infraclavicular

region

Collapsing or bounding pulse

Exercise intolerance

Signs of heart failure

Failure to thrive

Poor feeding

Respiratory distress

Patent Ductus Arteriosus

Investigations

Echo Doppler UIltrasound

Management

Medical management

Surgical ligation

Percutaneous catheter occlusion

Complications

Heart failure, infective endocarditis, pulmonary hypertension

and Eisenmenger syndrome

Eisenmenger Syndrome

A pulmonary vascular disease that develops in

patients with initial left-to-right shunts that then

reverse to become right-to-left

Triad of systemic-to-pulmonary cardiovascular

communication, pulmonary arterial disease, and

cyanosis

Can occur in congenital heart defects such as VSD,

ASD, and PDA

Eisenmenger Syndrome

Clinical Features

Central cyanosis

Digital Clubbing

Palpable P2 on

precordial palpation

Prominent “A” wave in

the JVP

Progressive heart failure

can cause peripheral

edema, hepatomegaly,

and ascites

Eisenmenger Syndrome

Management

Avoid high risk situtations such as pregnancy, isometric

exercise, high altitudes, or surgery

Advanced therapy for pulmonary hypertension

Bosentan, epoprostenol, sildanafil

Heart and lung transplantation with intracardiac repair

for severely symptomatic

Down Syndrome

Most common autosomal abnormality

40% have cardiac defects

Most are atrioventricular septaldefects (endocardialcushion defects)

Can also present with ASD, VSD, or TOF

Turner Syndrome

Cardiac

malformations can

include coarctation

of the aorta and a

bicuspid aortic valve

Patients should

receive echo and

ECG to screen for

these defects

Noonan Syndrome

An autosomal

dominant disorder that

affects males and

females

Similar phenotype to

Turner`s

Can present with

pulmonary stenosis

and ASD

DiGeorge Syndrome

Caused by abnormal development of the

pharyngeal pouch

Can present with cyanotic congenital heart disease

(80%)

Truncus arteriosus

Tetralogy of Fallot

Interrupted aortic arch

CHARGE Syndrome

Autosomal dominant disorder characterized by coloboma, heart anomalies, choanalatresia, growth retardation and development, and genital and ear anomalies

Cardiac abnormalities include tetralogy of Fallot, ASD, VSD

The End!

Investigations

Foundational Investigations

echo, ECG, CXR

Characteristic Chest X-Ray Findings in Congenital Heart Disease

Boot-Shaped Heart - Tetralogy ofFallot, Tricuspid Atresia

Egg-Shaped Heart - Transposition of

Great Arteries

"Snowman" Heart - Total Anomalous Pulmonary Venous Return

Any screening programs in Ireland? How are these managed here?