Congenital heart disease (CHD) is defined as a gross structural abnormality of the heart or intrathoracic great vessels that is actually or potentially of functional significance. Congenital heart diseases are related to congenital heart defects that develop during pregnancy and are present at birth. CHDs are the most common type of birth defect, affecting one of every 100 babies born in developed countries.
A study in Bangladesh reported that cyanotic heart diseases were commonly found in pediatric congenital heart disease and among them, Ventricular Septal Defect (VSD) was found the most common CHD. Atrial Septal Defect (ASD) was found 2nd the most common CHD. TOF is the commonest cyanotic lesion both in the past and present, though their frequency is reduced before. Early detection and detection of rare CHD during recent times may reflect the advancement of diagnostic skills and facilities as well as awareness.
This article will examine the state of pediatric congenital cardiac surgery in Bangladesh, including perspectives from medical professionals on the ground, as well as potential solutions that could help improve care.
Aetiology & risk factors
There are many different kinds of defects. Environmental and genetic factors contribute to the development of congenital heart disease. Common environmental factors include maternal illness (e.g, diabetes, rubella, systemic lupus erythematosus) or maternal intake of teratogenic agents (eg, lithium, isotretinoin, anticonvulsants).
Maternal age is a known risk factor for certain genetic conditions, especially Down syndrome, that may include cardiac defects. Paternal age may also be a risk factor. Certain chromosomal abnormalities are strongly associated with congenital heart disease. However, these abnormalities account for only 5 to 6% of patients with congenital heart disease.
Classification & pathophysiology
Congenital heart anomalies are classified as cyanotic and cyanotic. Cyanotic heart anomalies: Varying amounts of deoxygenated venous blood are shunted to the left heart (right-to-left shunt), reducing systemic arterial oxygen saturation. If there is > 5 g/dL (> 50 g/L) of deoxygenated hemoglobin, cyanosis results. Complications of persistent cyanosis include clubbing, thromboembolism, stroke, bleeding disorders, brain abscess, and hyperuricemia.
Hypercyanotic spells can occur in infants with unrepaired Tetralogy of Fallot (TOF). TOF is a common type of congenital heart disease. This defect makes up about 8 percent of all cases of congenital heart disease. They can affect blood flow to the lungs and body. Combinations of defects can create complicated conditions. All require careful diagnosis and management or treatment.
Acyanotic (left-to-right shunts or obstructive lesions): Oxygenated blood from the left heart (left atrium or left ventricle) or the aorta shunts to the right heart (right atrium or right ventricle) or the pulmonary artery through an opening or communication between the 2 sides. Immediately after birth, pulmonary vascular resistance is high, and flow through this communication may be minimal or bidirectional. Within the first 24 to 48 hours of life, however, the pulmonary vascular resistance progressively falls, at which point blood will increasingly flow from left to right.
The additional blood flow to the right side increases pulmonary blood flow and pulmonary artery pressure to a varying degree. The greater the increase, the more severe the symptoms. High-pressure shunts (those at the ventricular or great artery level) become apparent several days to a few weeks after birth; low-pressure shunts (ASD) become apparent considerably later.
If untreated, elevated pulmonary blood flow and pulmonary artery pressure may lead to pulmonary vascular disease and eventually ‘Eisenmenger syndrome’. Large left-to-right shunts (eg, large VSD, PDA) cause excess pulmonary blood flow and left ventricular volume overload, which may lead to signs of heart failure and during infancy often result in failure to thrive. A large left-to-right shunt also leads to lower lung compliance and higher airway resistance. These factors increase the likelihood of hospitalization in infants with upper or lower respiratory tract infections.
Manifestations & incidence
Manifestations of congenital heart disease may be subtle or absent in neonates, and failure or delay in detecting critical congenital heart disease, particularly in the 10 to 15% of neonates who require surgical or inpatient medical treatment in the first hours or days of life, may lead to neonatal mortality or significant morbidity.
Although Bangladesh has seen breakthroughs and progress in dealing with adult heart patients, for children the situation has not improved but has rather worsened. At present, nearly 4,00,000 children are suffering from various types of heart problems. The incidence of congenital heart disease is 8-10/1000 live birth which is established by many studies carried out in many centers worldwide.
In Bangladesh, no incidence study was carried out so far. A prospective study reported one hundred forty-two babies out of 5668 live birth had CHD, ie, 25/1000 live births. The incidence of CHD was higher in pre-terms as compared to full-term live birth. The most common congenital heart lesions were Atrial Septal Defect (ASD-26%), Ventricular Septal Defect (VSD-16.9%), Patent Ductus Arteriosus (PDA-18%), Tetralogy of Fallot (TOF-14%).
Treatment
The treatment for a congenital heart defect depends on the type and severity of the defect. Some babies have mild heart defects that heal on their own with time. Others may have severe defects that require extensive treatment. Medical stabilization of heart failure (eg, with diuretics, angiotensin-converting enzyme [ACE] inhibitors, beta-blockers, digoxin, spironolactone, salt restriction, and, in selected cases, supplemental oxygen or prostaglandin E1) are first-line treatment.
After medical stabilization of acute heart failure symptoms or cyanosis, most children require surgical or transcatheter repair. Highly significant, sequential improvements in survival and reductions in mortality, and morbidity after CHD surgery were seen in Bangladesh. Previous data demonstrate that, over the past 40 years, there have been substantial improvements in postoperative survival within all subgroups of complex CHDs, with early mortality now approaching zero. Parallel to these improvements, there has been a decrease in the need for reoperations.
Benefits of Pediatric Congenital Cardiac Surgery
Cardiac surgery in children is recommended to repair heart defects and for the child’s well-being in the long term. Certain heart defects may demand immediate surgery after birth. In some cases, surgeries are performed months or even years after birth. The type and number of surgeries needed vary on the severity of the condition. Benefits of surgery include: improved Quality of Life, reduced Hospital Stay, and reduced Risk of Complications
Challenges of Pediatric Congenital Cardiac Surgery in Bangladesh
Pediatric Congenital Cardiac Surgery is a rapidly advancing specialty addressing a large population of children as well as adults with congenital heart disease. It requires huge technical and financial resources; therefore, establishing, maintaining, and developing such services in limited resource settings are challenging. Bangladesh has the largest population density. Major Challenges of Pediatric surgery include lack of Expertise, cost, and limited Access to Facilities
Conclusion
Though with rapid progress, the pediatric cardiac specialty in Bangladesh still has no outstanding innovations and now is still chasing the steps of international peers. Advancing innovative surgery procedures requires the contributions of surgeons of one generation after another. Public awareness of CHD and surgeries is still lacking.
Knowledge about the prenatal diagnosis for CHD and intervention should be educated in pregnant women and the public. Due to the large population base, qualified fetal echocardiography doctors are far out of reach in Bangladesh. The government should increase the financial input in pediatric cardiac surgery. We should train more experience pediatric cardiac surgeons to grasp all complex techniques for improving patient care.
