AVSD: atrioventricular septal defect

An atrioventricular septal defect or AVSD is a combination of several associated lesions that are affected in the development of the valves between the top chambers (atria) and bottom chambers (ventricles) that result in a large defect in the centre of the heart. Also known as an endocardial cushion defect, the condition is congenital, which means it is present at birth, and occurs in two out of every 10,000 newborns. There is a strong association between this defect and the chromosomal abnormality, Down Syndrome.
When the heart is properly septated, red oxygenated blood from the lungs does not mix with the blue deoxygenated blood from the body. In an AVSD blood can move and mix freely among the four heart chambers. If left untreated, AVSD can cause inefficient blood flow through the heart and ultimately to

AVSD is not a single defect but rather a group of closely-associated defects in various combinations and with varying degrees of severity:
-Atrial component (communication between the top chambers)
-Ventricular component (communication between the lower chambers)
-AV valve (mitral and tricuspid) abnormality, failure of normal separation into 2 distinct particioed valves that separate the upper heart chambers (atria) from the lower chambers (ventricles), often resulting in one large “common” valve sitting over both right and left chambers.

How do we treat AVSDs
All of the AVSD subtypes, usually require surgery. The surgery, involves closure of any holes in the chambers, using patches. If the left sided AV valve does not close completely, it is repaired to make it more competent. The surgeon repairs the the common valve, separating it into two distinct valves – one on the right side and one on the left side.

The age at which surgery is dependent on clinical factors such as the child’s health and growth as well as the specific structure of the AVSD.  Ideally, surgery should be done before there is permanent damage to the lungs from too much blood being pumped to the lungs. Medication may be used to treat congestive heart failure, but it is only a short term measure in an attempt to allow the infant become bigger and strong enough for surgery.

Infants who have surgical repairs for AVSD generally remain under lifelong follow up. Some of the defects can be more complicated and there is a discrepancy in size between the 2 valves and the lower chambers, this is termed an unbalanced AVSD and can be more challenging to treat. Each AVSD is individual and the medical and surgical management are tailored to the defect. In some instances, children can require more than one operation. The most common need for reintervention is for complications of a leaky left AV valve. A child or adult with an AVSD will need regular follow-up visits with a cardiologist to monitor his or her progress, avoid complications, and check for other health conditions that might develop as the child gets older. With proper treatment, most babies with AVSD grow up to lead healthy, productive lives.

Coarctation

What is coarctation of the aorta?
The aorta is the major blood vessel carrying oxygenated (red) blood to the body. Coarctation of the aorta refers to a condition where there is a tightness (or narrowing) in this body artery. A coarctation is usually located just past the aortic arch, which has branches providing blood to the head and arms. When this defect is present, blood flow is restricted to the lower half of the body and the left ventricle muscle of the heart must pump harder to force the blood through the narrowed opening.

The clinical presentation is variable and depends principally upon the severity of the narrowing and the age of the baby or child. Milder degrees of coarctation are often not detected until childhood or adolescence and often come to light from the incidental finding ofweaker leg (femoral) pulses, a murmur or hypertension (high blood pressure). When the condition is severe, there can be reduced blood flow to the body in these children. In babies, this blockage can cause the left ventricle to weaken and make your baby very sick. In older children, this blockage can cause the left ventricle to thicken over time and also cause high blood pressure in the brain. If the muscle becomes too thick and is no longer able to function well, it can eventually fail.

Coarctation of the aorta occurs in about 6 to 8 percent of all children with congenital heart disease, and twice as frequently in boys. It also occurs in about 10 percent of girls who have Turner syndrome, a chromosomal abnormality.

Seventy-five percent of children with coarctation of the aorta also have a bicuspid aortic valve, in which the aortic valve has two leaflets, instead of the usual three. It can also be associated with other left sided heart defects and ventricular septal defects.

Treatment for coarctation of the aorta?
The majority of coarctations are treated surgically, although in older children who are suitable,  there is increasing experience with catheter-based (key-hole) interventions as well. Treatment strategies are tailored to the child’s age, size and the anatomy of the aortic arch as well as the presence of other associated cardiac conditions.

Patent Ductus Arteriosus (PDA)

What is patent ductus arteriosus?
Patent ductus arteriosus is a congenital heart condition where there is a persistent connection between the pulmonary artery and the aorta. This causes blood to mix between the two arteries and forces the heart and lungs to work harder. This special tube is necessary in fetal life before baby’s are born to allow them to use the placenta.  Usually, it is programmed to close spontaneously in the first few days of life after birth.

Patent ductus is the sixth most common congenital heart defect. It occurs in 5 to 10 percent of all children born with congenital heart disease. Patent ductus occurs twice as often in girls as in boys. It is more common in premature infants.

In babies with patent ductus, the fetal ductus arteriosus remains open (patent). This allows the oxygen-rich (red) blood to mix with oxygen-poor (blue) blood and forces the lungs and heart to handle a larger amount of blood than is normal. This is inefficient flow and causes the heart to work harder to meet it’s demands. If the PDA is large and if left over time it  can lead to heart failure.

 

Treatment children with a patent ductus arteriosus?
If the PDA is large enough to cause a haemodynamic burden on the child’s heart then we would advise to close the communication. Treatments, including medical therapy, minimally-invasive catheter-based interventions and minimally-invasive surgical solutions are available depending on the size and type of PDA.

Chest pain

Although the symptom of chest pain in your child can set off alarm bells in most parents, studies have shown in contrast to adults, the overwhelming majority of cases of chest pain in otherwise healthy children have a noncardiac aetiology. Numerous previous studies in multiple practice settings have demonstrated a cardiac aetiology in only 0-5% of children and adolescents presenting with chest pain.

True cardiac chest pain is rare in a teenager or child. A detailed clinical history of the nature, type and frequency of the pain can often help a padiatric cardiologist stratify whether the pain has an underlying cardiac cause. In the vast majority, a careful focused history and physical examination, along with a screening tests such as an ECG, will identify essentially all patients with a serious cardiac condition.

A 12 lead ECG (or electrocardiogram) is a valuable initial investiugation. This test involves placing 12 stickers or electrodes on the chest and analysing how the electrical impulses spread through the heart. The presence of other symptoms such as palpitations (an irregular or fast heart rate) or a history of syncope or collapse would prompt more detailed investigation and assessment. A positive family history of cardiac problems or history of early / unexplained death would also be a reason for further investigations.

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