By Joseph Constance BA, MA
A newborn may have a number of different defects of the heart that are congenital – already existing at birth. These types of defects of the heart can cause oxygen in the blood to be at low levels.
Cyanosis can occur and turn the color of skin and mucous membranes blue when the blood lacks the correct amount of oxygen. When cyanosis occurs along with a congenital heart defect, the condition is known as cyanotic congenital heart disease.
Causes of cyanotic congenital heart disease
As blood flows through the lungs and heart, blood that is poorly oxygenated, or low in oxygen, returns to the heart’s right side. It is blue in color. Then, that side of the heart moves the blood to the lungs where it changes from blue to red as it receives more oxygen. The blood, now laden with oxygen, moves to the heart’s left side from the lungs, and then is pumped back into the body to start its flow once again.
Congenital heart defects alter the blood flow process. Because of these defects, non-oxygenated blood flows from the heart throughout the body without moving through the lungs where it would normally acquire oxygen. Because the blood now moving throughout the body contains lower levels of oxygen, the skin turns a bluish tint. Cyanosis occurs. When heart defects causes cyanosis, the change in color may evolve slowly. If the amount of oxygen in the blood has decreased slightly, it might be difficult to recognize cyanosis. Moreover, cyanosis may appear more readily in the mucous membranes of those with darker skin.
Specific defects that can cause cyanotic heart disease and the skin to turn blue are:
- The inability of the tricuspid valve to open to its full extent or it may simply not exist.
- The inability of the pulmonary valve to open wide enough or it may not exist.
- The inability of the aortic valve to fully open.
Additional causes of the heart condition may include: a narrowing of the aorta; incorrect formation of the left side of the heart; an opening between the lower chambers of the heart; incorrect attachment of veins to the left atrium of the heart; and the interchange of the aorta and the pulmonary artery.
Symptoms of congenital heart defects
There are some congenital defects of the heart which do not present any, or only a few symptoms. For instance, these defects do not induce such painful symptoms as chest pain. Whether the defects show symptoms depends on how many defects there are, how intense they are, and the type of defect involved. Often in newborns, acute defects of the heart can yield symptoms, such as:
- Inefficient blood circulation.
To diagnosis cyanotic congenital heart disease, a physician will perform a clinical exam, take blood work, and analyze a patient’s concerns and symptoms. In addition, a cardiac MRI, ultrasound of the heart, electrocardiogram (ECG), X-ray, computerized axial tomography (CAT) scan or angiogram may be ordered.
Some patients, most often children, will require treatment for their congenital defect. At first, they may receive therapeutics to eliminate extra fluids and enable the heart to pump more effectively and treat any arrhythmias. Breathing equipment may also be necessary. Immediately after birth or later on, surgery may be required to repair the defect. The choice of procedure will be dependent on the type of defect involved.
Often, a catheter procedure will be performed to repair the defect, especially if it is a simple defect, such as a narrowing of one of the heart’s valves. This is preferred over surgery since it is less complicated. Recovery will be easier and more rapid. However, more serious defects, such as holes in the heart, may require open heart surgery.
A patient’s outcome after surgical treatment will depend on how complicated the defect was and how successfully it was treated. Potential complications include heart infections or failure, chronic hypertension, arrhythmias, stroke, or death.
Reviewed by Yolanda Smith, BPharm
Last Updated: Oct 12, 2016