Congenital diseases are disorders in a newborn due to certain genetic factors (and sometimes in association with the environment) that often results in malformations or underdeveloped organs. Congenital Heart Diseases (CHD) results in malformed or undeveloped heart that presents in a newborn with breathing and circulation disorders. According to Lancet medical journal, CHD caused death of 0.22 million individuals and newborns globally in the year 2010. CHD was earlier erroneously associated with premature births, the association has no direct correlation with all forms of CHD and is mainly one of the many factors that can cause it. The genetic factors causing CHD consist of chromosomal errors in fertilization and the following meiotic division, these include: large chromosomal defects in trisomal chromosomes; small chromosomal defects like microdeletion of long/short arm of chromosome and random/environmentally induced mutation of heart muscle cell proteins, or associated proteins etc. The environmental factors like rubella infections, thalidomide drugs, metals (lithium, lead, mercury, etc), chronic illness in the mother (systemic lupus, diabetes, phenylketonuria, etc). Embryological changes, hormonal changes in the mother and certain birth deficiencies can also cause CHD and other birth defects in children. Besides these, according to some medical research reports_bk_01_01_2020, maternal obesity increased the chances of CHD in newborns; obesity was shown to increase the risk of previously hidden genetic traits of CHD in the new born children of such obese mothers.
CHD can be diagnosed before birth via ultrasound sonography; however some minute heart defects may go undetected for life. CHD is primarily classified as hypoplasia( underdeveloped heart chambers), obstructive (blockage/narrowing of valves/vessels) and septal defects (defects in the septum wall that divides the heart chambers). However, medical practitioners generally distinguish CHD at birth into Cyanotic (blue coloration of skin due to very low Hb/oxygen) or non-cyanotic. Cyanotic disorders usually present as problems that prevent normal circular of blood, therefore resulting in poor oxygen supply, some examples include: left ventricular hypoplastia, pulmonary atresia (abnormal closing/opening of a valve), tricuspid atresia, pulmonary venous return, etc. Non –cyanotic disorders involve problems in the heart that may present difficulty for the child in the future and result in cardiac arrhythmia, chest pain and difficulty in breathing, some examples include: Aortic stenosis, Atrial/ventricular septal defect (ASD), pulmonic stenosis, coarctation (turner’s syndrome), patent ductus arteriosus, etc. CHD are in some cases associated with certain chromosome syndromes e.g.: Down syndrome, Marfan syndrome, Noonan Syndrome, Turner Syndrome and 22q11 sequence deletion syndrome (DiGeorge syndrome), etc.
The treatment of CHD varies from case to case; genetic testing/screening is mandatory in case the doctor suspects a genetic cause for the disease, in developed countries this is done for all newborns. The next step would be surgery or drug treatment, again this depends upon the severity of the condition. In most cases CHD presents itself as serious conditions with high risk of complications, hence surgery is the most followed procedure. In certain disorders like ASD a pediatric surgeon may ask the parents of a CHD child to wait for the child’s growth as ASD is known to disappear gradually, a surgery is performed if ASD persists after the child’s growth. Certain cases also require multiple surgeries and stenting in order to restore a malformed tract in the lungs, etc. Drugs like diuretics are given to regulate vasoconstriction that alleviates deoxygenation and helps remove toxins from the body, besides reducing the heartbeat.
CHD is commonly reported through the world and is known to affect one in 5000 newborn births. Treatment and surgeries are done in large numbers in both developed and developing countries. At present the market is largest in the North American, Asia-Pacific and European region because these regions together form the most populated yet urbanized region in the world. Asia-pacific region leads the global market at present and is expected to maintain its position in the near future.
Some of the diuretic manufacturers include: Pfizer inc., Abbott Laboratories Inc., Eli Lilly & Co, Ranbaxy Pharmaceuticals Inc., et to name a few.