Understanding Cardiovascular Diseases: Part 2 – What is Congenital Heart Disease CHD?
It is estimated that 8 children per 1000 live births suffer from CHD, going by this rate approximately 1,80,000 children in India are born with CHD every year.
By Dr Saleha Noorain
After having gone through atherosclerotic cardiac diseases in the previous article in the August 2018 issue, this article will focus on the other diseases affecting the heart, namely congenital heart disease and rheumatic heart disease.
Congenital Heart Disease includes a spectrum of conditions that are present since birth affecting the structure and function of the heart and are a result of a defect in the development stage of the fetus. It is one of the most common type of birth defects and is estimated that 8 children per 1000 live births suffer from CHD, going by this rate approximately 1,80,000 children in India are born with CHD every year.
The cause could be due to many reasons, some of which include heredity, certain medications used by the mother during pregnancy, alcohol consumption and smoking by the mother, certain illnesses afflicting the mother during pregnancy and environmental exposure. However in most cases, it is difficult to point to a particular cause.
Broadly they are classified into:
i. Cyanotic CHD- often referred as blue baby. It results from defect in the structure of the heart that allows mixing of pure (arterial) and impure (venous) blood.
ii. Acyanotic CHD: more common type of CHD. Usually due to presence of hole in the heart.
The key to the management of these lesions is early recognition of the presence of CHD. Most, but not all lesions can be picked by prenatal ultrasound scan done during pregnancy and for others it is recommended that all newborns be screened for CHD by trained personnel within 24 hrs of birth. However, inspite of this, some of these defects may not manifest themselves so early and are likely to be missed during the initial evaluation. Hence, the mother should be instructed to look out for any unusual symptoms or signs like hurried breathing, poor feeding, bluish discolouration, repeated cough and cold in her baby, and report immediately.
These lesions are usually diagnosed with the help of an echocardiogram, which is an ultrasound scan of the heart. More complex lesions require cardiac catheterization, an invasive test. Most of them require surgery, which could be curative or palliative in nature. The timing and number of interventions vary depending on the structural defect.
Acute Rheumatic Fever (ARF) and Rheumatic Heart Disease(RHD):
ARF is an inflammatory disorder which follows 2-3 weeks after a sore throat caused by a type of bacteria called group A streptococcus. It is a multisystem disorder, but mainly affects the heart, brain, joints and skin. It usually lasts for several weeks with fever, joint pains. It typically leaves no residual damage to the brain, skin and joints, however, when the heart is involved, its valves get damaged leaving behind what is known as Rheumatic heart disease(RHD). Repeated episodes of streptococcal sore throat and ARF leaves the heart vulnerable to repeated insults and further worsens the condition.
Who is at risk for ARF and RHD?
The first episode of ARF is most commonly seen in children aged between 5- 15 years, although it can affect at any age. Girls are more commonly affected than boys. Poor hygienic conditions, poor economic background and overcrowding increases the susceptibility to this infection.
How can it be prevented?
Recognizing and timely treatment of streptococcal sore throat can prevent the occurrence of ARF. This is known as primary prevention. Once there is an established episode of ARF, it becomes very important to prevent recurrent episodes in order to prevent the development of RHD or worsening of the damage already caused to the heart valves. This is what is known as secondary prevention. It is done by regular penicillin, an antibiotic, prophylaxis which will be guided by your doctor. Till date, this has been the only strategy shown to be clinically effective and cost beneficial at the community level in the fight against RHD.
(The writer is Consultant Interventional Cardiologist, Primecare Hospital).