Hello, it means the abnormality of cardiovascular structure or function that exists at birth. It is caused by abnormal development of cardiovascular system or developmental disorders (such as atrial septal defect and ventricular septal defect) during fetal period and by the failure of degenerated tissues (such as patent ductus arteriosus) after birth. Imagine the development of the heart as building a house. The problems in building a house are like congenital heart disease: the walls between the houses are defective: such as atrial septal defect (normal left and right atria are completely independent), ventricular septal defect (normal left and right ventricles are completely independent); temporary water pipes are not removed in time when building a house: such as patent ductus arteriosus (fetal, pulmonary artery and active). There is an artery duct between the arteries to circulate blood and close atrophy normally at birth; the door in the house can not be completely opened or closed: such as pulmonary stenosis, aortic valve malformation; there is a fistula between the hot and cold pipes causing cold water not cold, hot water not hot: such as pulmonary arteriovenous fistula, coronary arteriovenous fistula; the electrical wires in the house are not conductive: such as congenital completeness. Atrioventricular block. Atrial septal defect, ventricular septal defect and patent ductus arteriosus are the most common types of congenital heart disease. For more information, please leave a message.