The heart has four chambers.The two lower pumping chambers of the heart which are known as the ventricles, and the two upper filling chambers which are known as the atria. In normal blood circulation, blood that returns from the body have low percentage of oxygen flows to the right-side filling chamber called the right atrium . This blood is then passed to the right-side pumping chamber called right ventricle.This blood is then passed to the lungs to receive oxygen. Then the oxygen-enriched blood comes back to the left- side filling chamber called left atrium and then moves to the left-sided pumping chamber called left ventricle. Now this blood rich in oxygen is pumped out to the body through the aorta, a large blood vessel that carries blood to the smaller blood vessels in the body to deliver oxygen. The right and left-sided pumping chambers called the ventricles are separated by shared wall called the ventricular septum.

What is Septal Defect?

The ventricles are the 2 lower chambers of the heart. The wall between them is called the septum. A hole in the septum is called a septal defect.

Ventricular septal defect is a hole in the wall between the right and left ventricles of the heart. This abnormality generally develops before birth and is found most unfortunately in infants.

Atrial septal defect is the hole present between the upper chambers or atria.

Infants may be born with either or both types of defects. These conditions are known as "holes in the heart." The risk for these problems depends on the size of the hole in the septum and how well the infant’s lungs function. Based on research it has been estimated that approximately eight in 1,000 newborns have congenital heart disease (CHD). A Ventricular septal defect (VSD) is the most frequent of the various types of congenital heart disease (25%-30% of all CHD). Datas reveals that approximately one infant in 500 are born with a VSD.

What problems do Ventricular septal defects cause ?

During contraction of the left ventricle higher pressure is generated which is higher than that generated by the simultaneous contraction of the right ventricle. Which results the blood to be pushed through the ventricular septal defect this is known as "shunted" from the left ventricle to the right ventricle. This means that to handle the additional blood volume the right ventricle has to do extra work. As a result it may face a trouble keeping up with the load and may enlarge and thus affecting its ability to pump efficiently. On the other hand the lungs receive too much blood under too much pressure. Which leads the small arteries called arterioles in the lungs to be thicken to response the excess blood under excess pressure. If this extra pressure exists then it will result in permanent damage to the lungs. It makes a considerable difference whether the size of the VSD is small or large.

What are the causes of the Ventricular septal defect?

In science it is not very clear what causes ventricular septal defects, but they probably come from a malformation of the heart that occurs while the infant is developing in the womb. In the first weeks after conception, the heart is developed from a large tube, dividing into sections that becomes the walls and chambers. If a problem occurs during this process, a hole in the ventricular septum may be caused. In some other cases, a genetic deficiency may lead to develop a Ventricular septal defect. There can be genetic syndromes that cause extra or missing pieces of chromosomes that can be the cause of Ventricular septal defect. For the vast majority of children with a defect, however, there's no evident reason as to why a Ventricular septal defect develops.

There may be just one hole or several holes in the septum. The septum itself is divided into multiple areas, including the membranous part, the muscular part, and other areas called the inlet and outlet. Any or all of these parts can have a hole in it. The location of the hole totally depends on where the malformation had taken place during fetal development. Membranous variant is however the most common type of ventricular septal defect. In this case the hole is present below the aortic valve, which controls flow of blood from the left ventricle into the main artery of the body known as the aorta.

What are the Symptoms of Ventricular septal defect?

Ventricular septal defects are usually found in the first few months of life by a doctor during a routine checkup. The size of the hole and its location in the heart will determine whether someone experiences symptoms of Ventricular septal defect. Small holes in the ventricular septum usually produce no symptoms but are often recognized by the child's health care provider when a loud heart murmur along the left side of the lower breast bone or sternum is heard.Teens who have small VSDs that haven't closed yet usually experience no noticeable physical signs other than the heart murmur that the doctors hear. They may need to see a doctor regularly to check on the heart defect and make sure there aren't any problems.

But large holes typically produce symptoms 1-6 months after an infant’s birth. The left ventricle begins to fail, producing the following symptoms like..

• Fast breathing
• Sweating
• Pallor
• Heartbeats goes fast
• Decreased feeding
• Poor weight gain
  If the ventricular septal defect is not detected early days, it can lead to more severe problems and more serious symptoms with time. The high pressure generated in the lungs (pulmonary hypertension) is the biggest concern. If the defect is not treated surgically it can lead to irreversible pulmonary hypertension and then the defect in the child can no longer is operable and has a poor prognosis. The symptoms of pulmonary hypertension are..
  
• Fainting
• Shortness of breath
• Chest pain
• Bluish discoloration of the skin (cyanosis). That is skin turns faintly bluish as the tissues are not receiving quite enough oxygen and such a condition is termed as "hypoxemia" or "hypoxia"

Fortunately, though, advancements in medicine during the past few decades mean that most kids with moderate to large VSDs are treated long before the VSD ever causes pulmonary hypertension.

How is a VSD diagnosed?

The diagnosis of a VSD is usually suspected clinically by the doctor by hearing a characteristic heart murmur. A abnormally turbulent flow of blood through the heart generates this murmur sound. Blood is shunted through the VSD from the higher-pressure left ventricle into the lower-pressure right ventricle which generates this sound. If your doctor notices a heart murmur that was not noticed earlier, you may be referred to a pediatric cardiologist( a doctor who specializes in diagnosing and treating heart disease in kids and teens.) In addition to a physical examination the doctor will also note the medical history of the patient like past health, family health, any medications you are taking, any allergies you may have, and other issues. If the cardiologist thinks a person might have a VSD, he or she may order one or more of the following tests to confirm it like ..

• a chest X-ray
• an electrocardiogram (EKG)
• an echocardiogram (echo)
• a cardiac catheterization

If a doctor diagnoses someone with a VSD, treatment will depend on age, the size of the hole, and where it's located in the heart.

What are the Treatments for Ventricular septal defect(VSD)?

If the VSD is small

If the defects are small say less than 0.5 square cm which is quiet common, there is no reasons to worry. This is because, as there is minimal shunting of blood and the pressure in the right ventricle remains normal. There will be no damage to the lung arterioles, since the right ventricular pressure is normal. The heart functions normally, but a prominent murmur is heard through a stethoscope. This murmur is generally noticed during the first week of life.

One-third to one-half of all small VSDs close on its own as the child grows. This occurs most often before the child is 1 year old to almost 4 years old, generally 75% of child with small VSDs are cured by 2 years of age. Even if a small VSD does not close on its own, surgical repair is gererally not recommended. However, long-term follow-up is adviced.

If the VSD is large

If the VSD is large generally greater than 1 sqaure cm, then there is a reason to worry. This is because there is a significant shunting of blood from the left ventricle into the right ventricle. The right ventricle is strained by the extra blood volume and thus the lungs suffers with an increase in the blood pressure called "pulmonary hypertension." The symptoms in the child are labored breathing, difficulty feeding, grow poorly, and have pallor.

The patient with a large VSD will need surgery to "patch the hole" in the ventricular septum. The timing of the surgery is an personal decision depending upon many factors. Like

A) The duration and the extent of increased pulmonary artery pressure. Chronic pulmonary arteriolar pressure may become irreversible and put a strain on the right ventricle. However, such side effects can be treated with medications until surgery is appropriate.

B) A child with a large VSD often suffers from poor growth. The increased metabolic demands requires additional calories as compared to children without such a cardiac defect. High-calorie dense supplements are added to formula. Nighttime continuous feedings is required for some infants. This is done by using a tube that is passed through the nose to the stomach known as nasogastic tube to maximize growth. However this is very rare case, so as to restrict fluid volumes in these children.

C) Infants with iron-deficiency anemia are given iron supplements to maximize the oxygen carrying capacity of their blood. Blood transfusions to solve such a case are rare.

What are the Types of surgery are available to cure a VSD?

Surgery is indicated if medications do not work in the first few months or years of life. However, there are two types of surgery available to cure a VSD. They are

1. The intra-cardiac technique
2. The trans-catheter technique.

Which surgical technique will be selected is a very personal decision based upon the condition of the VSD and the added side effects on the patient's heart and lungs. However, the intra-cardiac approach is the most common technique. It is an open-heart operation. It is done keeping the patient is under a "heart-lung machine". This is the procedure selected for most children and at most pediatric surgical centers. The other technique uses surgical instruments which are passed through catheters placed in the patient's large blood vessels into the heart. This technique that is the "trans-catheter approach" is generally more difficult and should only be operated on select patients and at pediatric centers that have specialist in this very procedure.

Surgery is not usually performed in newborns because small defects will close on its own in 20-25%. The surgery also is more risky in the first few months of life. It is to be noted that the risk of death from the operation is higher in the first 6 months of life than later.

What is the result after a successful VSD surgery?

After a successful surgical VSD repair, the two ventricles are entirely separate from each other and there is a normal circulation of the blood within the heart. The heart will return toward its normal size if it was enlarged. The high pressure in the pulmonary artery should also begin to resolve. The growth rate in the child will increase and the child generally catches up within a year or two. Long-term follow-up like regular doctor's office visits, echocardiograms and regular check of child's weight and length/height are required. Feeding and activity levels should be assessed routinely.VSD (repaired or not) needs to take antibiotics before dental procedures, including cleaning and other dental care, and before surgical procedures on the mouth or throat.

What are complications of VSD surgery?

There are very rare complications with intra-cardiac VSD surgery. Studies reveals that currently, if the VSD is the only defect present in the patients heart, then in most centers the operative mortality rate is less than 1%. Major complications are rare that is 1%-2%, which include heart rhythm problems and incomplete closure of the VSD. In very rare cases, a pacemaker insertion or a second procedure to resolve the defect are needed. However, some cases with multiple VSDs ("Swiss cheese" defects) are also harder to treat.

VSD generally has an excellent long-term outlook
For other Cardiac problems go through.
Angioplasty
Heart Transplantation
Coronary Bypass
Heart Valve Surgery