Pat De Paolo April 1, 2011
Dr. Servidio Anatomy- Physiology
Tetrology of Fallot
Tetralogy of Fallot is classified as a specific heart defect that causes low oxygen levels in the blood. This leads to cyanosis, which is a purplish/ blue coloring to the skin. Tetralogy of Fallot causes 4 major heart defects. The first is the Ventricular septal defectwhich can be classified as a hole in between the left and right ventricles. The second heart defect is Narrowing of the pulmonary outflow tract which causes an increase in pressure in flowing blood from the heart to the lungs. The third defect is an overriding aorta which shifts the aorta over the right ventricle and the ventricular septal defect. This causes problems for the oxygenated blood to pass from the left ventricle into the rest of the body. The fourth heart defect caused by Tetralogy of Fallot is ventricular hypertrophy which is the thickening of the ventricular cardiac muscle which creates high blood pressure. Tetralogy of Fallot is uncommon, but it is the most common form of cyanotic congenital heart disease. Patients with Tetralogy of Fallot have a higher incidence of major non-heart defects such as liver and lung capillary defects.
Tetralogy of Fallothappens during pregnancy and many factors lead to having this congenital heart disorder. The cause of Tetralogy of Fallot is unknown but factors that contribute to it are Alcoholism in the mothers, Diabetes, and Mothers who is over 40 years old during pregnancy and more. In addition, there is a high chromosomal disorder in children with Tetralogy of Fallot such as Down syndrome and DiGeorge syndrome.
Symptoms of Tetralogy of Fallot may appear at birth of a very young age. On occasion, symptoms may appear later in childhood. Visual symptoms include Clubbing of fingers (which is a bone enlargement around the fingernail area), difficult feeding, a failure to gain weight, passing out, poor development, and episodes during cyanosis (Blue skin) called Tet spells.
Tetralogy of Fallot can be diagnosed by a Chest X-ray, Complete blood count, Echocardiogram, Electrocardiogram, MRI of the heart (usually preformed after surgery).
There are 3 major treatment options of Tetralogy of Fallot. The first treatment is an emergency management of tet spells. This is done by intervening with a vasopressor such as epinephrine, phenylephrine, or norepinephrinewhich increases blood pressure. Also oxygen can be added to the body to increase the blood flow to the lungs. The second treatment is Palliative surgery. This redirects a large portion of the partially oxygenated blood leaving the heart for the body into the lungs, increasing flow through the pulmonary circuit, and greatly lessening symptoms in patients. The third treatment option is a potentially life threatening treatment. It is a complete surgical repair or open heart surgery. This is done to relieve the right ventricle outflow to decrease the ventricular hypertrophy.
If left untreated, Tetralogy of Fallot is life threatening and isapproximately 75% survival after the first year of life, 60% by four years, 30% by ten years, and 5% by forty years. This is a very dangerous heart defect that must be followed up after any surgical procedures because patients have a high risk of cardiac death and heart failure as the heart grows to adult size.