Cyanotic heart disease is the most common congenital heart lesions which are present in children at birth which results in low blood oxygen tension. Cyanosis means bluish discoloration of the skin and mucous membrane due to the de-oxygenated blood supply.
Causes of Cyanotic heart disease
The common cause of Cyanotic heart diseases are
- Tetralogy of Fallot
- Transposition of great arteries
- Ebstein anomaly
Tetralogy Of Fallot (Tof)
The most common cause of Cyanotic heart disease is Tetralogy of Fallot, which is present in 5-7 percent of children and compatible with life. It is caused by environmental factors or genetic factors or both. The major’s components of Tetralogy of Fallot are
- Ventricular septal defect (VSD)
- Atrial septal defect (ASD)
- Pulmonary stenosis
- Right ventricular hypertrophy (RVH)
- Overriding of aorta
Due to the septum defect in the atrial wall or ventricular wall, blood is shunted from the right chamber to the left chamber and result in the mixing of blood. Due to pulmonary stenosis, there is an obstruction in the right ventricular outflow, which can lead to right ventricular hypertrophy in later life.
Signs & Symptoms of Tof
Symptoms begin to appear during the first week of life due to the mixing of blood from right to left shunting but vary according to the severity of the disease.
Labored breathing at rest.
- The baby may or may not be cyanosed at birth.
- Growth and development are retarded.
- Low oxygenation of the blood
- Clubbing of fingers and toes
- Heart murmurs
- Dyspnea at rest
- Children used the squatting position as it reduces the venous return and increases the resistance, thus decreases right to left shunt.
- Hypoxic, blue spells
- Failure to gain weight
- The infant becomes irritated, restless, cyanosed, hyperpneic and grasped breathing.
Pulse is usually normal.
- Difficulty in feeding
- Heart size is normal, but parasternal heave may be present.
- Second heart sound is often single.
INVESTIGATIONS FOR TETRALOGY OF FALLOT
Following investigations and tests are done to make the diagnosis.
Complete blood count
This blood test shows the moderate raised amount of hemoglobin, RBCs, and hematocrit, depending on the oxygen saturation.
It shows right ventricular hypertrophy and right axis deviation.
Heart size is normal on chest radiograph. The characteristic finding of Tetralogy of Fallot is, the heart appeared as Boot shaped heart on x-ray. Apex is lifted. Moreover, pulmonary vascular markings are reduced and in 25 percent of cases, the aortic arch is right-sided.
It is done to clarify the coronary artery and pulmonary artery anatomy.
It shows Ventricular septal defect (VSD), Atrial septal defect (ASD), Pulmonary stenosis, Right ventricular hypertrophy (RVH), Or Overriding of the aorta.
WHO IS AT RISK?
The mothers who are alcoholic, diabetics, have had rubella infection during pregnancy or age greater than the 40s, are at high risk of having the baby with these congenital heart defects.
WHAT ARE THE COMPLICATIONS OF TETRALOGY OF FALLOT?
In infants, this Cyanotic heart disease can lead to
- Brain abscess
- Cerebrovascular accidents
- Bacterial endocarditis
- Psychosocial problems
- Pulmonary regurgitation
- Management Of Tetralogy of Fallot
- Irregular heart rate
Our aim is to prevent the hypoxia and to increase the blood flow lungs. It can be treated by medicines as well as by surgery.
1- Medical Therapy
Electrolytes are maintained by infusion of fluids and keep hydrated to prevent the hemoconcentration. Blood glucose level should be monitored regularly to prevent the hypoglycemia. Temperature is maintained. Iron supplements are given to correct the exercise intolerance. Advised the patient’s mother to feed the baby and increase the calorie intake to prevent the growth retardation. Bacterial endocarditis prophylaxis must be given.
Drainage and antibiotics should be given to cure the brain abscess. Maintain oral hygiene. Counseling is also important for psychological problems.
2- SURGICAL THERAPY
Open heart surgery is preferred for this type of congenital heart defects. VSD closure, ASD closure, creation of systemic artery to pulmonary artery shunt and opening of the pulmonary artery by open surgery are the best options to treat this congenital heart defects.