Dr. Bharat Dalvi, had his training in paediatric
cardiology at the Children’s Hospital, Boston; Hospital for Sick
Children, Great Ormond Street, London; and the Cleveland Clinic Foundation, Cleveland.
The human heart is made up of four chambers. The upper ones are the right and left atria,
separated by a wall
called the inter-atrial septum. The lower chambers are the
ventricles, the right and left separated by the inter-ventricular
septum.
The left side of the heart has oxygen-rich, ‘pure’
blood (or ‘red blood’). The right side of the heart has
oxygen-poor, ‘impure’ blood (or ‘blue blood’). The ‘red
blood’ from the left ventricle is pumped to the body through a big
arterial vessel called the aorta. The ‘blue blood’ from the right ventricle is carried to the lungs for oxygenation
through the pulmonary artery.
Normally, the pressure on the left side of the heart is
more than on the right. Therefore, the flow of blood in
septal defects (hole in the heart) is from left to right. Thus,
in uncomplicated septal defects, the patient is pink and
does not have cyanosis (the blue colour of the skin and mucous membranes).
Frequently asked questions about congenital heart
disease now follow:
When Should You Suspect That Your Child Could Be Having A Heart Disease?
When the child has:
Rapid
and distressed breathing
Blue
discolouration of the nails, lips or tongue
Feeding
difficulty — she is not sucking well or has to leave the nipple every now and then for a gasp of breath
Recurring
cough with fever (ie. chest infection)
When
the child is not growing well (inadequate weight gain), and her physical milestones are not in keeping
with her age.
How Does A Paediatric Cardiologist Diagnose Heart Defects?
With
the help of medical history, including birth history.
By
performing a thorough physical examination.
By
ordering certain investigations. The most common ones are an X-ray chest,
ECG, Doppler echocardiography and cardiac catheterisation.
Can My Child With CHD Participate In All Physical Activities?
The majority of children with CHD are fully active and
usually do not need any restriction. Activity should be
promoted. Swimming, cycling and running should be encouraged. In a few children with specific heart problems, the
paediatric cardiologist may advise against strenuous playing
activities or competitive sports.
If My Child Has A ‘Murmur’ In The Heart, Does It Mean He Has A Heart Problem?
A ‘murmur’ is an abnormal sound heard by a family
physician or a paediatrician with his stethoscope. Not all murmurs
are produced by abnormalities in the heart. In some children with murmurs, the heart is functionally and structurally
normal. Such murmurs are referred to as ‘innocent’ or ‘functional’
murmurs.
COMMONLY OCCURRING CONGENITAL HEART DISEASES
ATRIAL SEPTAL DEFECT (ASD): It
is a defect in the partition separating the two atria. Usually, the left
atrial pressures are higher than the right atrial ones. Hence,
the blood flows from the left to the right atrium; ie. pure
blood mixes with impure blood. This results in increased
volume of blood going to the right heart chambers and the lungs.
TREATMENT: There are surgical and non-surgical (transcatheter) modalities available.
Do ASDs Close Spontaneously?
Small ASDs detected on echo immediately after birth or
during infancy may close spontaneously, but most of the ASDs
that are moderate or large sized do not close on their
own.
What Is The Ideal Age For Closure?
ASDs can be closed at any age, but if the child is asymptomatic, the defect can be electively
closed at
around 3 years.
Which Of The ASDs Can Be Closed Without Surgery?
ASDs which measure 20 to 22 mm on echo and which are located in the central portion of
the partition are
suitable for non-surgical closure. They constitute about 30% of all ASDs.
PATENT DUCTUS ARTERIOSUS (PDA): A
patent ductus arteriosus is an open tube that connects the two
major arteries arising from the heart — the aorta (AO) and
the pulmonary artery (PA). This tube is normally open when
the child is in the mother’s womb.
When Does The PDA Usually Close?
PDA closes within a few hours after birth. In premature babies, it may remain patent for a
longer time,
sometimes even weeks.
What Are The Ways In Which A Premature Child With PDA Presents?
Flow through the ductus and the degree of prematurity
decide the time and nature of presentation in the newborn. The commonest presentation is in the form of shortness
of breath and the inability to provide adequate oxygen to
the body. Such babies need extra oxygen. A large PDA may actually need to be assisted by a
breathing machine (ventilator).
After The First Year Of Life, PDA May Present With:
Shortness
of breath
Feeding
difficulties
Repeated
respiratory tract infections (cough with fever)
Failure
to gain weight
Delayed
physical milestones — delay in crawling, rolling over, sitting with support…
Repeated
episodes of cough
Infection
of the heart valve or vessel (infective endocarditis)
Or
it may be incidentally detected during routine examination.
How Can A PDA be fixed?
It can be closed either with surgery or with
non-surgical techniques. Surgical ligation of PDA does not require
use of cardiopulmonary bypass. Non-surgical techniques involve closing the
ductus with the use of stainless steel coils
or an umbrella made of a material called nitinol.
VENTRICULAR SEPTAL DEFECT (VSD): It
is a defect in the partition separating the two ventricles.
Usually, the left ventricle (LV) pressures are higher than the
right ventricle (RV) ones. Hence the blood flows from the LV
to the RV through the defect. This results in oxygenated, pure
blood going back into the lungs, resulting in the heart having
to pump an extra amount of blood. However, if a large
defect is left untreated, the pressure in the lung arteries tends
to increase. This results in impure blood from the RV
flowing into the LV and subsequently into the body.
SYMPTOMS depend upon the size of the hole and the pressure in the RV.
During the newborn period, the pressures in the RV are high and the child may be completely
asymptomatic
despite a large defect. By 6 to 8 weeks of life, the pressures in
the right heart chambers tend to normalise, resulting in increased
flow through the defect, producing symptoms.
Symptoms in infancy include:
Shortness
of breath or increased effort to breathe
Repeated
lung infections or pneumonia
Poor
growth
Delayed
milestones
Feeding
difficulties
Those babies with large VSDs who are not operated upon
in infancy or early childhood may present during late
adolescence or adulthood with shortness of breath, fatiguability and
bluish discolouration of the lips and nails. This is due to
development of high pressures in the lung vessels, resulting in the
impure blood being shunted into the body across the VSD.
Do All Babies With VSD Have These Symptoms?
No. Those with small holes can be completely
asymptomatic and may be detected on routine examination for an
unrelated problem.
Is It Necessary To Close All VSDs By Surgery?
No. Small VSDs do not need surgical closure. Many of
them may even close spontaneously. Only the large ones that produce symptoms and/or cause overload on the heart need
to be closed surgically.
What Is The Ideal Time To Close A VSD?
This depends on the size of the VSD, and the experience
and expertise of the operating team. A large VSD causing significant symptoms should be closed immediately. Some
of the VSDs that do not produce significant symptoms but
result in high pressures in the lungs during infancy should
also be closed immediately. The earlier such defects are closed,
the greater are the chances that the pressures in the lungs
will normalise.
Moderate-sized VSDs that are neither producing symptoms nor causing lung pressures to go
up can be closed
electively by about 3 years of age.
Till What Time Are These Holes Expected To Close On Their Own?
Most of the holes that will eventually close are
expected to close by 5 years of age. Thereafter, spontaneous closure
of the VSD is unlikely.
VALVULAR PULMONARY STENOSIS (PS): This
is a stenosis (narrowing) of the pulmonary valve that guards
the orifice between the RV and the PA.
Do All Patients With PS Need Treatment?
No, if the PS is mild, the child could be left alone
without any intervention. Such children have been shown to have
normal quality of life and longevity when compared to their
normal counterparts. However, if it is moderate or severe, the
valve obstruction needs to be relieved in order to prevent its
ill effects on the RV.
What Are The Modes Of Treatment Available?
The treatment of choice for valvular PS is balloon
pulmonary valvuloplasty (BPV). This is a non-surgical method of
dilating the valve with the use of a specialised balloon
catheter. In less than 5 % of patients, balloon dilatation may not work,
in which case surgical relief of stenosis may be required.
VALVULAR AORTIC STENOSIS: This
refers to a narrowing of the aortic valve. The aortic valve guards
the orifice separating the left ventricle from the aorta.
Do All Patients With AS Need Treatment?
No. Mild aortic stenosis may be left alone. But some of
these mild AS, over a period of time, become moderate or
severe, in which case they need to be relieved. Thus all AS,
including the mild ones, need to be under regular medical
supervision. Moderate or severe AS needs to be treated before it
affects the LV function.
What Are The Modalities Available For Treatment?
AS can be relieved by a specialised balloon catheter.
This procedure is called balloon aortic valvuloplasty (BAV).
The other option is surgical, which involves either repair
or replacement of the valve.
COARCTATION OF THE AORTA:
In this condition, the aorta is usually constricted distally, after it has
given rise to the branches supplying the brain and upper part of the
body.
What Are The Effects Of Coarctation Of Aorta On The Circulation?
The blood pressure above the narrowing is high. If left untreated, the left ventricle muscle
becomes thick. Ultimately, the left ventricle fails to deliver blood to
the body commensurate with its needs. This is referred to as left ventricular failure
(LVF).
Do All Patients With Coarctation Need Treatment?
If the coarctation is very mild, the child may be left
alone. But any coarctation that has resulted in high blood pressure
or has affected LV muscle thickness and/or contractility will need treatment. Moreover, if the pressure difference between
the upper and lower portion (ie. before and after the
narrowing of the aorta) is more than 25 mm Hg, the coarctation will
need to be relieved.
What Are The Modalities Of Treatment Available For Babies With
Coarctation?
Coarctation can be fixed surgically by cutting off the
narrow portion and suturing the two ends of the aorta together.
The other way of surgical correction is by using a patch to
widen the narrow segment. This patch could be borrowed from
the vessel to the arm or a synthetic material could be used.
The non-surgical option involves balloon dilatation of
the narrow segment. This is achieved by passing a special catheter called a balloon catheter from the
groin. This
is a catheter which has a balloon mounted on its tip. The
balloon is placed across the narrow segment and inflated so as
to widen the narrow segment.
BLUE BABIES (CYANOTIC HEART DEFECTS):
Babies with cyanotic heart disease are more commonly known as “Blue Babies”. This is a
group of defects
where the blood pumped into the body has less than the normal
oxygen. This causes bluish discolouration of the skin, lips and
tongue (cyanosis). The cyanosis could be mild or severe,
depending on the nature of the defect, the age of the child and
the level of activity. Cyanosis is known to worsen with activity
and is often relieved by rest. Indians’ darker skin
complexion and presence of anaemia may result in parents being unable
to recognise mild cyanosis; even doctors may sometimes overlook it.
TETRALOGY OF FALLOT (TOF)
What Are The Structural Abnormalities In Patients With TOF?
TOF has 4 structural defects
Large defect in the partition separating the two ventricles (pumps). This is the
VSD.
Narrowing of the pathway leading from the RV to the pulmonary artery is most often at/or just below the
pulmonary valve.
The right ventricle is more muscular than normal.
The aorta, instead of originating from the left
ventricle, arises from both RV and LV, i.e. it is located just
above the VSD.
What Are The Effects Of TOF On Circulation?
The major abnormality is decrease in the amount of blood going to the lungs due to
obstruction to blood flow. The
other important problem is the impure blood from the RV entering the aorta across the defect in the partition separating
the two ventricles (VSD), resulting in the mixing of pure and
impure blood. As a result, the babies with this abnormality become blue and are referred to as ‘Blue Babies’.
What Are The Various Presentations Of Children With TOF?
Parents may notice cyanosis.
Growth of these children is usually poor.
Shortness of breath and fatiguability on exertion.
Some of them may present with sudden episodes of severe cyanosis with rapid breathing
which may be progressive
and end up with convulsions (fits) or loss of consciousness.
What Treatment Can Be Offered To These Babies?
They need open heart surgery for correction of this
anomaly. viz. closing the partition defect (VSD), removing the obstructing muscle and opening the pulmonary valve if
narrow. Some of these babies are not suitable for a
complete repair. These children can be temporarily relieved by increasing blood flow to the lungs with a shunt.
This procedure involves making a connection between the A0 and PA. This helps reduce cyanosis and allows the
child to grow.
Do These Children Need Any Medicines?
While the children await surgical intervention, they are treated for anaemia (if present).
Children who have worsening cyanosis on exertion may be put on betablockers (a group of medications which blunts
the heart’s response to exercise).
When Is The Ideal Time For Total Intracardiac Repair (ICR)?
The ideal time for total ICR is variable, depending on
the experience of the surgical team as well as the exact
nature of the abnormality. Most of the centres in India would
prefer complete ICR by the age of around 2 to 3 years.
Do These Children Need Follow-Up After Surgery?
They do need a regular follow-up to assess the effects
of surgery as well as to see the effect of any leftover
defects (residual).
TRANSPOSITION OF GREAT ARTERIES (TGA)
What Are The Abnormalities Seen In This Condition?
Normally, the PA carries the blue blood from the RV to
the lungs for oxygenation, and the aorta carries the pure
red blood from the LV to the whole body. In TGA, the PA is
connected to the LV, and the aorta to the RV. This results in
purified blood going back to the lungs and impure blood going
back into the body.
If impure blood goes into the body and pure blood back
into the lungs, how do these babies survive?
In order to survive, infants born with this defect need
to have at least one or more communications which allow the red blood and the blue blood to mix so that at least a
part of the pure red blood goes into the body circulation. These connections may be in the form of
ASD, VSD or PDA.
What Symptoms Do These Babies Present with?
Most of these children present in the newborn period
with cyanosis and/or breathing difficulties. If the diagnosis
is not made immediately and proper treatment is not started,
the baby could die within hours or a few days.
What Treatment Can Be Offered To These Babies?
To improve the oxygen supply to the body, a special procedure called balloon
atrial septostomy (BAS) is
done. It involves enlarging the natural hole present in the
interatrial septum. This helps the baby by improving the mixing between the pure and the impure blood, thereby reducing
the cyanosis in such cases.
What Is The Definitive Mode Of Treatment For Babies With TGA?
There are two types of surgeries that are used to
correct TGA. Your doctor can give you the details.
When Should You Suspect That Your Child Could Be Having A Heart Disease?
