HEART DISEASE IN CHILDREN

Introduction

Heart disease are not uncommon in childhood and constitute a significant proportions of children admissions in hospital. In particular, congenital heart disease account for 30% of all heart diseases for all ages.

Functions of the heart

The human heart is a muscle that works like a pump. The right side of the heart receives deoxygenated or "blue" blood from the body and pumps it to the lungs to add oxygen. The left side receives this re-oxygenated "red" blood from the lungs and pumps it back out to the body.

If the heart and blood vessels are abnormal in any way or the heart does not pump properly, the patient can get sick and have heart disease.

Different Types of Heart Disease

Heart disease in children may be congenital or acquired.

Congenital Heart DiseaseCongenital heart disease is the kind that a patient is born with, but it's not that common. The incidence is 8-10 per 1000 livebirths. It can be caused by heredity or viral diseases like rubella.

Acquired Heart DiseaseAcquired heart disease develops sometime during childhood as a result of illnesses like rheumatic fever, myocarditis, endocarditis, pericarditis etc.

Arrhythmia

Arrhythmia is an abnormal rhythm of the heart. Normally, the heart beats at

60-150 beats per minute in older children and adults, and

100-140 beats in infants and young children,

but a person's heart can beat very fast (tachycardia) or very slow (bradycardia).

Symptoms and signs of heart disease in children

Depend on type and severity of the heart disease a patient has. They include:

Cyanosis;Shortness of breath on exertion (breathing and feeding problems); Cardiac failure Recurrent lower chest infections Poor growth (failure to thrive

Precordial bulging;

Squatting

Hypoxic spells

Cardiac murmur

In older children

Palpitations

Syncope

Heart Murmurs

A heart murmur is a whooshing sound between each heartbeat. The whoosh isn't serious, but is just an extra noise that the blood makes as it flows through the heart. However, sometime murmurs can be a symptom of larger problems. The intensity of the murmur is not proportional to severity of the heart disease

EVALUATION OF THE CARDIOVASCULAR SYSTEM

A.History

1. Cynosis .

a. Peripheral cyanosis (i.e. bluish coloration around the mouth and over the eyelids but not of the mucous membranes) is normal in infants

b. Cyanosis of the of the mucus

membranes is diagnostic of a

right-to-left shunt; however it

may be sub-clinical and is

sometimes present only on

exertion.

2. Other factors relevant to cardiac

funtion include:

Shortness of breath

Exercise intolerance

Dyspoea on exertion

Feeding difficulty in infants and young children

Difficulty in growth (failure)

Squatting.

Syncope

Palpitations

3.Familial disorders

Some cardiovascular disorders (e.g. hyperlipidaemia, hypertension) may be familial

4. Chest pain

It is common in the pediatric age-group, particularly in adolescents but it is rarely of cardiac origin.

Analysis of specific features (e.g. quality, distribution, relationship to level of activity) helps to distinquish anginal pain from pain due to more benign causes

B. Pysical examination

a.Abnormal weight (failure to thrive).

b.Other important observations:

i. Dyspnoea; ii. Cyanosis; iii.Clubbing of fingers and toes which indicates a right –to-left shunt; iv.Signs pointing to a syndrome or genetic disorder that includes congenital heart disease

2. Pulses

The presence or absence of peripheral pulses should be noted. It is important to palpate both brachial arteries simultaneous for timing and volume. If both are equal, a brachial artery and a femoral artery should be palpated simultaneously to rule out a coarctation of the aorta. If there is carctation of the aorta the femoral pulse will be weak and delayed.

Collapsing peripheral pulses are caused by:

Patent ductus arteriosus (PDA)

Aortic regurgitation

Large Arterio-venous shunts (A-V shunts)

Paget’s diseaseof bone

3. Blood pressure

Should be measured over the brachial and popliteal arteries

The cuff should have a bladder approximately two thirds the size of the extremity and that completely covers its circumference

The diastolic pressure is recorded at the disappearance of the Korotkoff sounds

4. Precordial palpation

a. Location of the apex beat

i. Displacement downwards and outwards indicates cardiomegaly

ii.Displacement to the opposite side indicates dextrocardia

b. Presence of heave.

i. Apical heave = LVH.

ii. Left parasternal heave = RVH

5. Cardiac auscultation.

Heart sounds.

1)The first heart sound (S1) may be single or split.

2)The second heart sound (S2) is split during inspiration but the split is narrow.

Abnormalities of S2:

i. Wide fixed split occurs in ASD,

RBBB, Pulmonary valve stenosis

ii. Accentuation of S2

The puomonary component of S2 is accentuated in pulmonary hypertension

The aortic component of S2 is accentuated in:

systemic hypertension;

transposition of the great arteries

3) Third heart sound (S3)

Alone it is normal in children

May represent a pathologic condition if associated with other abnormal findings

4) Fourth heart sound (S4)

Always abnormal in children

b. Clicks

Ejection clicks are heard shortly after S1. Originate from opening of stenotic semi-lunar valves namely: i. pulmonary stenosis, and ii.aortic stenosis

Mid- or late systolic clicks indicate: i. mitral valve prolapse, or ii.ticuspid valve prolapse

c. Cardiac murmurs

(i)Innocent (functional) murmurs. Almost universally present at some time during childhood. They: i. Are soft, ii. Localized, iii. Systolic ejection except venous hum which is continuous, and iv. Not associated with a thrill, v. They do not radiate, and vi. They change with posture.

(2) Pathological murmurs.

May occur during systole or diastole.

(a)Systolic murmurs.

(i) Rergugitant MurmursBegin with S1. They are also called

pansystolic or holosystolic murmurs because most of them extend throughout the whole systole. They are heard in: VSD, AV canal defects, mitral regurgitation and tricuspid regurgitation

(ii) Ejection systolic murmurs.

Begin after the isovolumetric contraction of the ventricles.

They coincide with the opining of the semi-lunar valves.

They are caused by:

Aortic stenosis

Pulmonary stenosis

(iii) Late systolic murmmurs

Late systolic murmurs are associated with mitral valve prolapse

(b) Diastolic murmurs

(i) Early diatolic

(protodiastolic) murmurs

Begin with S2, decrease in intensity and by mi-diastole. Are caused by semi-lunar valve regurgitation. Therefore, heard in: pulmonary regurgitation and aortic regurgitation

(ii) Mid-diastolic murmurs

Caused by impaired flow across AV valves. Therefore, heard in: mitral stenosis and tricuspid stenosis

(c) Systolic-diastolic (machinery or

continuous) murmurs caused by

PDA

C. Laboratory evaluation

1.Chest X-ray.

Permits evaluation of:

Heart size,

Status of the pulmonary vasculature which may be: normal, diminished (oligaemic) or increased (pleonaemic)

Sites of cardiac structures and other viscera

2. Electrocardiography (ECG)

The ECG:

Permits diagnosis of cardiac arrhythmias

Reflects anatomic changes e.g. ventricular or atrial hypertrophy that develop in patients with cardiac disease

Indicates presence of myocardial infarction

4. Cardiac Catheterization

Cardiac catheterization allows:

Measurement of intra-cardiac and intravascular pressures

Determination of pressure gradients across the cardiac valves

Oximetry to determine type, level and size of shunts

Cardiac output

Selective angio-cadiography which allows

Visualization of cardiac and

vascular anatomy, and

Therapeutic intervention in some

cases

D. Principles of treatment

1)Counseling

2)Medical treatment

3)Treatment of cardiac failure if and when present

4)Treatment of hypoxic spells if and when present

5)Prevention of endocariditis

END