Congenital heart disease refers to a birth defect in the heart. Congenital heart defects are the most common form of birth defects, happening in about 1 out of every 150 births. Symptoms from a congenital heart defect can vary quite a bit, primarily depending on the type of heart defect. Generally speaking, congenital heart defects can be classified in one of three categories. The first category is termed a left to right shunt. In this setting, blood is usually sent through a hole in either the lower or upper wall of the heart, or sometimes through a communication outside the heart, back to the lungs. Examples include a ventricular septal defect, atrial septal defect, or patent ductus arteriosus. In the setting of a small defect, most children won't show any symptoms whatsoever. However, if the defect is large enough, symptoms are usually caused by too much blood flow going to the lungs. The most common symptom in this situation is rapid breathing. This is because some of the water from the bloodstream can leak out into lung tissue, interfering with the exchange of oxygen and carbon dioxide. The child subsequently has to breathe harder to overcome this problem. This often raises the child's metabolic rate, causing slow weight gain and poor growth. Finally, extra lung water and related problems may predispose to more frequent lung infections, for example pneumonia.
The second category of congenital heart defect that can result in symptoms is a right to left shunt. In this setting, deoxygenated blood (blood without oxygen) bypasses the lungs to return to the body. Examples of cyanotic heart defects may include tetralogy of Fallot, transposition of the great arteries, and tricuspid atresia. Symptoms related to a right to left shunt are usually caused by an insufficient amount of oxygen in the bloodstream. Children with these problems often appear cyanotic (they have a bluish discoloration to their skin). They frequently become easily fatigued and tired with exercise because of worsening cyanosis.
A final category of symptoms may be related to excess stress on the heart muscle. This can be found in certain forms of valve abnormalities or other obstructions. Examples of these forms of congenital heart defects may include aortic valve stenosis, pulmonary valve stenosis, and coarctation of the aorta. If severe enough, these children are at risk for congestive heart failure. In this setting, the heart pumps an inadequate amount of blood to the body. Symptoms related to congestive heart failure may include difficulty breathing or shortness of breath related to back up of blood into the lungs, or easy fatigue with exercise due to inadequate blood flow to the body.