Congenital heart disease (CHD) is the most common congenital disorder in newborns.

There are no published data on the occurrence of congenital heart disease in Kerala. However there is general agreement among health workers that it follows a similar pattern all over the world in different geographies. The reported prevalence of CHD at birth ranges from 6 to 13 per 1000 live births. On an average, 8 children are born with congenital heart defects for every 1000 live births in India. Variation is primarily due to the use of different methods to detect CHD (fetal echocardiography versus postnatal referral to a cardiac center). Deriving from the crude birth rate, it is estimated that about 5000 babies are born in Kerala every year with congenital heart defects.

Critical CHD is defined as requiring surgery or catheter-based intervention in the first year of life.

Critical CHD accounts for about 25 percent of all CHD. In infants with critical CHD, the risk of morbidity and mortality increases when there is a delay in diagnosis and timely referral to a tertiary center with expertise in treating these patients. Those babies who do not receive adequate treatment during this period face mortality, or lead a truncated life.

Conventionally these defects are classified into two major groups, cyanotic and non-cyanotic. Cyanotic heart defects present with cyanosis (bluish discoloration of lips and finger tips) as a symptom. This is due to reduced amount of oxygen in the circulating blood because of abnormal mixing within different chambers of the heart. Absence of cyanosis as a symptom does not in any way mean that the disease is less severe.

Unlike in adults, congenital heart disease means structural defects in the anatomy of the heart. These defects are due to abnormal development of the heart during fetal life.

The most common congenital heart defect is a bicuspid aortic valve (BAV), with a prevalence estimated between 0.5 and 2 percent, but it is rarely diagnosed in infancy. The next most common defects are ventricular septal defects (VSDs) and secundum atrial septal defects (ASDs, prevalence of 4 and 2 per 1000 live births, respectively. Tetralogy of Fallot (TOF) is the most common cyanotic CHD (0.5 per 1000 births).

Often it is difficult to ascertain the reason for occurrence of congenital heart disease in a particular baby, however certain factors have been identified to carry risk of developing these defects.

The following factors are associated with an increased risk of CHD and should alert the clinician to suspect CHD

  • Prematurity − Risk of CHD (excluding isolated patent ductus arteriosus [PDA]) is two- to threefold higher in preterm (gestational age <37 weeks) compared with term infants.
  • Family history − there is an overall increased risk for CHD when a first-degree relative has CHD
  • Genetic syndromes − Genetic and extra cardiac abnormalities are common in patients with CHD: chromosomal defects were detected in 7 percent of patients with CHD. Many genetic syndromes are associated with an increased risk of CHD (eg. Down’s syndrome).
  • Maternal factors − Maternal conditions that increase the risk of CHD include diabetes mellitus, hypertension, obesity, phenylketonuria, thyroid disorders, systemic connective tissue disorders, and epilepsy. In addition, drugs taken during pregnancy (e.g., phenytoin) as well as smoking and/or alcohol use can be associated with cardiac defects
  • Assisted reproductive technology (ART). Some studies have shown that there is a marginal increase in occurrence of heart defects in babies born of assisted reproduction technology.
  • In utero infection − CHD may result from congenital infections (eg, rubella). Maternal influenza or flu-like illness during pregnancy is also associated with increased risk of CHD. Congenital cardiomyopathy may result from viral infections (cytomegalovirus, cox sackie, herpes virus 6, parvovirus B19, herpes simplex), toxoplasmosis gondii, and possibly human immunodeficiency virus (HIV).

Identifying the presence of CHD can be sometimes difficult. In affected newborn infants, parents most commonly notice difficulty with feeding. This may be manifested by intake of a limited volume of milk, or feedings that are frequently interrupted by choking, gagging, or vomiting. Infants may have respiratory distress that is reported by parents as fast or hard breathing, worse with feedings, or a persistent cough.

Other manifestations include:

  • Color changes, such as central cyanosis or persistent pallor
  • Unexplained irritability
  • Excessive sweating particularly of the head
  • Poor weight gain
  • Decreased activity or excessive sleeping
  • Delay in motor milestones

Often CHD is suspected by a pediatrician upon routine examination at vaccination. Presence of a cardiac murmur, or absence of peripheral pulses could point to diagnosis.

Pulse oximetry should be an important part of routine examination of babies, which can help detection of reduced oxygen saturation levels. This facility is not very expensive, and now available with every clinic catering to small babies.

However the best person to suspect congenital heart disease is the mother herself. Small changes in the behavior pattern of the baby are usually reported by the mother. The clinician should take a good history from the mother or grandmother.

Routine diagnostic methods are utilized in this case also. Chest X ray and ECG help a lot in narrowing down the diagnosis. However it should be said that the single most important diagnostic tool is echo cardiogram.

Echo performed by an experienced pediatric cardiologist can make an accurate diagnosis in 90 % of cases. Cardiac CT scan and cardiac MRI scan are also important tools in more complex anatomy.  Rarely do we require invasive methods like cardiac catheterization.

It is now possible to diagnose these conditions while the baby is still in the womb. It is common practice that obstetricians do routine examination using ultra sound at appropriate intervals. Whenever needed, this is followed by fetal echo cardiogram performed by a cardiologist specially trained in this. A reasonable accurate diagnosis can be made by as early as 16 weeks of intra uterine life.

It has been our experience that most of the pediatricians who send babies to tertiary care centers are able to make a fairly accurate diagnosis. Usually at higher centers only some fine tuning is necessary. This shows the high level of efficiency at peripheral clinics also.

Timing of intervention in CHD is also an important aspect.

Children with critical CHD may require intervention even as early as first day of life. This depends on the nature and severity of the disease; and the condition of the baby. For example, conditions like pulmonary atresia, total anomalous pulmonary venous connection, hypo plastic left heart syndrome etc. may require intervention in the first week of life itself.

Certain other conditions like ventricular septal defect (VSD), usually can be repaired after 3 months unless some life threatening situation arises in the meantime. The common condition like ASD is repaired just before joining school.

Certain unfavorable conditions like single ventricle physiology, can be managed only by staged multiple operations.

Surgical correction is the gold standard in the treatment of congenital heart disease, because basically these are structural defects. Occasional defects like small VSD may get spontaneously corrected, but needs close observation while awaiting spontaneous recovery.

Currently another form of treatment is available. Some of these defects can be treated by cardiac catheterization based treatment. Some holes can be closed with a device delivered through a catheter entering through a blood vessel. Similarly a shrunken valve may be opened by a balloon mounted on a catheter.

It is heartening to note that most the defects now are amenable to surgical/catheter based treatment giving the baby near normal life expectancy and quality of life, if not permanent cure.

Those children who are not diagnosed early in life may present in adulthood. They can also be now offered effective treatment. Grown up congenital heart disease (GUCH) is an evolving sub specialty.

Prevention of congenital heart disease may not be always possible. What expectant mothers could do is to follow a healthy life style, attending regular checkups and avoiding unnecessary medications. Whenever CHD is suspected, help of a pediatric cardiologist should be sought.

CHD is a major contributor to infant mortality in Kerala. IMR in the state is around 10, which is far below the national average. This was possible because we could get control over infectious diseases in last 30 years or so. Now if you have to further reduce infant mortality and morbidity, we have to have effective management of CHD.

The main bottle neck in controling this disease is finances. Parents of these kids are still young, with minimal savings. Unfortunately the facilities for treatment of CHD need huge investment which may adversely impact on hospital bills. Insurance companies generally shy away from providing care for congenital defects, barring a few new companies. Nationalized insurance companies we hope will be able to make up this viability gap, if the society at large and Government particularly take up the matter seriously.

Dr. Sajan Koshy

 

 

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about Dr sajan koshy
Pediatric Cardiac Surgeon



Dr Sajan Koshy MS MCh is currently heading the unit of Paediatric & Congenital heart surgery at Aster Medicity. Prior to joining Aster, he was working as senior consultant and head of the department of paediatric cardiac surgery at MIMS Calicut. He started his professional career from alleppey medical college in 1988. He also functioned as a co- convener in first and second symposia on perioperative care of congenital heart disease held in Kochi in the year 2002 and 2004 respectively & as the scientific committee chairman for the national CME of cardio thoracic surgery held at Calicut in September 2007. He has Conducted many lectures in all the districts of North Kerala for the benefit of medical professional bodies to create awareness about congenital heart disease.

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