The clinical features are the result of the disturbances to the normal heart action and functioning produced by the exact problem. If there is a defect in one of the walls separating the chambers such as an atrial or ventricular septal defect, there is likely to be some abnormal shunting of the blood across these defects. The direction of the shunt also determines some of the clinical features. If the direction of the shunt is from the left side to the right, the strain is primarily felt on the right side of the heart and the chambers on that side tend to get enlarged in response to the extra work that side is called upon to perform. This clearly depends on the size of the defect and the actual amount of blood that is shunted across the defect. Small defects that produce minimal shunting may remain completely symptom less for a long period of time. In the case of shunts that produce abnormal flow from the right side to the left, the cardinal problem is the mixing up of venous or low oxygen containing blood with oxygenated blood on the left side of the heart. The resulting general lowering of the oxygen content of the blood from the left side of the heart leads to a certain amount of oxygen depleted blood being pumped to the rest of the body and the tissues. This leads to the classical sign of cyanosis which is a bluish tinge in the peripheries, nail beds, lips tongue etc.

In certain cases of congenital heart problems major alterations of the heart sounds are produced. Doctors use these features heard with a stethoscope to try and arrive at an initial diagnosis. There may be accentuation of softening of the normal sounds produced by the action of the heart and the heart valves depending on the type and size of the problem. There may also be additional sounds known as heart murmurs produced particularly by either the flow of blood through narrowed valves, extra amounts of blood going through normal valves or by the blood being shunted across through septal defects. These sounds are produced by the abnormal turbulence resulting from altered dynamics of flow of blood through the heart. The loudness, timing and character of these murmurs provide important information to the doctor regarding the possible sites and degree of the underlying problem.

Abnormalities of growth may occur in affected children. For normal physical growth it is essential that an adequate amount of properly oxygenated blood circulates through all areas of the body. Congenital heart problems may lead to either inadequate amounts of blood being pumped by the heart or to inadequately oxygenated blood being circulated to the tissues. Depending on the degree of involvement these growth disorders may assume major proportions. In some children it may be so severe as to literally provide a stature consisting of skin and bones only.

Abnormalities of blood flow through the lungs produce problems with breathing and shortness of breath with exertion. Generally, the lungs tend to get congested and it becomes quite an effort for the affected child to move them with the respiratory efforts. In addition, the affected lungs are also more prone to develop lung infections. In fact, one of the presenting symptoms of certain types of cardiac shunts is recurrent or poorly resolving lung infections. In extreme cases which are associated with heart failure, the lungs get severely affected and this is also combined with increased fluid retention within the body leading to swelling of ankles and abdomen.

Some congenital heart defects cause serious symptoms right at birth, requiring even newborn intensive care in the hospital and immediate evaluation by specialists. They usually have major breathing difficulties. They may need immediate intervention to save the life of the child. Other defects, like small atrial septal defects, may go undiagnosed until the teenage years or for that matter, even into adult life.

When there are reasonable grounds to suspect the presence of a congenital cardiac defect, certain investigations may be needed to assess the child. Generally the first steps are to perform the most non-invasive and least distressing investigations first. After an initial complete physical examination, including evaluation of the baby’s heart rate and blood pressure, the doctors would generally order a chest X-ray to evaluate the size and shape of the heart and to view the lungs. An electrocardiogram (ECG) is also usually done, too. ECGs are performed by placing small pads or electrodes known as leads on a child’s chest, which are wired to a monitor that records and prints out the electrical signals of the heart. By analyzing these waves of electrical activity of the heart it is often possible to get some idea of the enlargement of certain chambers and also to detect abnormal electrical activities that may have led to abnormal patterns of heart beat.

These basic investigations would almost invariably be followed by the performance of an echocardiogram. This test too is completely non-invasive and simply needs only a sensing tranducer to be moved gently across the surface of the chest. The instrument emanates harmless sound waves and the simultaneous reflections and echoes of the sound waves are sensed, measured and mapped out by the very same transducer. This investigation provides detailed images of the heart, is able to demonstrate all of the heart chambers and valves, the great arteries arising from the heart and the direction and speed of blood flow in various areas of the heart. Echocardiograms can also evaluate whether the heart is squeezing and relaxing normally. This investigation has obvious benefits in pediatrics cardiology and is now the primary tool and the investigation of choice for diagnosing congenital heart defects.

A fetal echocardiogram is a specialized type of ultrasound that allows diagnosis of certain heart problems even before the baby is born and while it is in the mother’s womb. This can be done as early as 16-18 weeks of gestation. These tests are usually ordered when the obstetrician suspects a heart abnormality on an obstetric ultrasound scan. They are also often undertaken if there is another close family member with a congenital heart defect or when the mother has a condition, such as diabetes, which may predispose to the occurrence of congenital heart problems in the fetus.

Some of the newer techniques of cardiac imaging are very useful for exact delineation of the cardiac defects. These use XMR which is a new diagnostic technique that combines magnetic resonance imaging (MRI) and conventional x–rays and combined computerized tomography CT and MRI (CT-MRI), to create a unique three dimensional image of the heart which greatly improves a physician’s ability to measure blood flow and ascertain how the heart is beating. Such imaging tests usually require significant sedation in the case of infants and young children since the patient must stay perfectly still during the entire imaging process.

Cardiac catheterization is sometimes performed as well. During this procedure, a long, thin tube called a catheter is threaded through blood vessels in the periphery or the groin and up into the heart. Once in place, the catheter can measure the oxygen levels and pressures within the heart’s chambers. Dye may be injected through the catheter to better illustrate the heart’s inner structures and determine the direction of blood flow through the heart. This procedure is an invasive test and is nowadays undertaken only under very special circumstances

Performing these investigations to definitively diagnose the defect does not mean that immediate intervention may always be required. Some defects need only regular reassessments to evaluate how the heart is able to cope with the problem. In other cases treatment needs to be planned and undertaken with the minimum of delay. All this needs judicious consideration of the findings in a coordinated way. Some defects get better as time goes by and the effects on the heart get less with time. This is particularly true for some types of septal defects.

It is indeed a comforting thought that help is available for many of these children affected by congenital heart diseases. Some of these defects for which nothing very much could be done just up to a couple of decades ago can be completely cured today. Many different types of interventions to solve the problems of congenital cardiac malformations are available today. Some can be dealt with using modern technology using minimum interventions while others may need open heart surgery. In that sense, accurate diagnosis of the problem and its effects on the heart are of paramount importance. With continuing advances being made in the field of pediatrics cardiology, many problems could be solved and there are only very few defects that cannot be effectively dealt with today. In many cases, definitive forms of treatment can cure the problem. In those rare cases where such curative treatment is not possible, something could be done to mitigate the ultimate effects of the problem. Some of these children with eminently treatable defects would be quite normal and will have a normal life-span when treated adequately. Unlike some of the serious cardiac problems that affect adults, many congenital cardiac malformations in children are often associated with a much happier outcome. The technology, the resources and the expertise are available in our own country to deal effectively with many of these unfortunate children affected by such malformations.