Tetralogy of Fallot ( TOF ) is a type of heart defect that exists from birth. Symptoms include episodes of bluish color on the skin. When babies are exposed to crying or bowel movements, they can develop a "spell tet" where they turn blue, have difficulty breathing, become limp, and sometimes lose consciousness. Other symptoms may include heart murmurs, clubbing fingers, and fatigue during breastfeeding.
The cause is usually unknown. Risk factors include mothers who use alcohol, diabetes, are over 40 years old, or get rubella during pregnancy. It can also be linked to Down's syndrome. Classically there are four defects:
- pulmonary stenosis, narrowing out of the right ventricle
- ventricular septal defect, hole between two ventricles
- right ventricular hypertrophy, right ventricular muscle thickening
- the aorta that overwrites, allowing blood from both ventricles to enter the aorta
TOF is usually treated with open heart surgery in the first year of life. The operation time depends on the baby's symptoms and size. This procedure involves increasing the size of the pulmonary valve and pulmonary artery and repairing the ventricular septal defect. In infants that are too small a temporary operation can be done with a plan for a second operation when the baby is bigger. Most affected people grow into adults. Long-term problems may include irregular heartbeat and pulmonary regurgitation.
TOF occurs in about 1 in 2,000 newborns. Men and women are affected equally. This is the most common congenital heart complex. Originally described in 1671 by Niels Stensen. A further explanation was published in 1888 by the French physician ÃÆ' â € ° tienne-Louis Arthur Fallot, after whom his name was. The first surgical repair was performed in 1954.
Video Tetralogy of Fallot
Signs and symptoms
Tetralogy of Fallot produces low blood oxygenation because oxygenated blood mixing and deoxygenation in the left ventricle via ventricular septal defect (VSD) and preferential flow of mixed blood from both ventricles through the aorta as obstruction flows through the pulmonary valve. This is known as the right-to-left shunt. The main symptoms are low blood oxygen saturation with or without cyanosis since birth or developing in the first year of life. If the baby is not cyanotic then it is sometimes referred to as "tet red". Other symptoms include a heart murmur that can range from almost invisible to very severe, feeding difficulties, failure to gain weight, stunted growth and physical development, activity dyspnea, fingers and toes, and polycythemia. The baby may turn blue by nursing or crying.
Tet spell
Children with tetralogy of Fallot can develop a "tet spell". This is an acute hypoxia mantra, characterized by shortness of breath, cyanosis, agitation, and loss of consciousness. This may be initiated by any event causing decreased oxygen saturation or which leads to decreased systemic vascular resistance, which in turn causes increased shunting through ventricular septal defects.
Tet spells are characterized by sudden and marked cyanosis increases followed by syncope, and can lead to hypoxia and death brain injury.
The bigger kids will often squat over the tet spell. This increases the resistance of the systemic blood vessels and allows a temporary reversal of the shunt. This increases pressure on the left side of the heart, reducing right to left shunting, reducing the amount of deoxygenated blood entering the systemic circulation.
Maps Tetralogy of Fallot
Cause
The cause is thought to be due to environmental or genetic or combination factors. It is associated with 22 chromosome removal and DiGeorge syndrome.
Special genetic associations include:
- JAG1
- NKX2-5
- ZFPM2
- VEGF
Embryological studies show that it is the result of anterior septal malformation of the aorticopulmonary septum, resulting in a clinical combination of VSD, pulmonary stenosis, and impinging aorta. Right ventricular hypertrophy develops progressively from resistance to blood flow through the right ventricular outflow channel.
Pathophysiology
Four malformations
"Tetralogy" denotes four parts, here implying four signs of syndrome. It does not become confused with the same teratology of its name, the field of medicine related to abnormal development and congenital malformations (including tetralogy of Fallot). Below are four cardiac malformations present together in tetralogy of Fallot:
There is an anatomical variation between the individual heart and the tetralogy of Fallot. In particular, the rate of right ventricular outflow obstruction varies between patients and generally determines clinical symptoms and disease progression.
Presumably, this arises from the uneven growth of the aorticopulmonary septum. The aorta is too large, so "toss it aside," and this "steals" from the pulmonary artery, which is therefore stenosis. This then prevents ventricular wall closure, therefore VSD, and this increases the pressure on the right side, so the R ventricles become larger to handle the job.
Additional anomalies
In addition, tetralogy of Fallot may present with other anatomical anomalies, including:
- left pulmonary artery stenosis, in 40%
- bicuspid pulmonary valve, in 60%
- right side aortic arch, in 25%
- coronary artery anomalies, within 10%
- patent foramen ovale or atrial septal defect, in this case the syndrome is sometimes referred to as the pentalogy of Fallot
- atrioventricular septal defect
- the return of partial or complete anomalous pulmonary veins
- rib forks and scoliosis
Tetralogy Fallot with pulmonary atresia ( pseudotruncus arteriosus ) is a severe variant in which there is complete obstruction (atresia) from the right ventricular outflow channel, resulting in the absence of a lung stem during embryonic development. In these individuals, the blood shunt is entirely from the right ventricle to the left where it is pumped only through the aorta. The lungs are diffused through the extensive collateral of the systemic arteries, and sometimes also through the ductus arteriosus.
Diagnosis
Congenital heart abnormalities are now diagnosed with echocardiography, which is rapid, involves no radiation, is very specific, and can be done before birth.
Before more sophisticated techniques are available, chest x-ray is the definitive diagnostic method. The abnormal "abnormal" abduction of the heart with tetralogy of Fallot is classically seen through chest X-ray, although most babies with tetralogy may not show this finding. The absence of secondary interstitial pulmonary markers for pulmonary oligaemia is another classical finding in tetralogy, such as pulmonary pulmonary marker.
Treatment
Tet spell
Tet spells can be treated with beta-blockers such as propranolol, but acute episodes require rapid intervention with morphine or intranasal fentanyl to reduce ventilation drive, vasopressor such as phenylephrine, or norepinephrine to improve systemic vascular resistance, and IV fluids for volume expansion.
Oxygen (100%) may be effective in treating incantations because it is a strong pulmonary vasodilator and systemic vasoconstrictor. This allows more blood flow to the lungs by reducing deoxygenated blood shunting from the right ventricle to the left through VSD. There are also simple procedures such as squats and knee position which increase the resistance of systemic blood vessels and reduce the right shunting of deoxygenated blood into the systemic circulation.
palliative operation
The condition was initially deemed untreatable until surgeon Alfred Blalock, cardiologist Helen B. Taussig, and laboratory assistant Vivien Thomas at Johns Hopkins University developed a palliative surgical procedure, involving side formation to end anastomosis between the subclavian artery and the pulmonary artery. This first operation is depicted in the movie Something Created by the Master . It was Helen Taussig who convinced Alfred Blalock that the door would work. This directs most of the partially oxygenated blood leaving the heart to the body to the lungs, increasing the flow through the pulmonary circuit, and greatly reducing the symptoms in the patient. The first Bluntock-Thomas-Taussig shunt operation was performed on 15-month-old Eileen Saxon on 29 November 1944 with dramatic results.
The Potts shunt and shunt Waterston-Cooley are another shunt procedure developed for the same purpose. This is no longer used.
Currently, Blalock-Thomas-Taussig shunts are not usually performed on infants with TOF except for heavy variants such as TOF with pulmonary atresia (pseudotruncus arteriosus).
Total surgical repair
The Blalock-Thomas-Taussig procedure, originally the only surgical treatment available for tetralogy of Fallot, is palliative but not curative. The first total improvement of Fallot's tetralogy was done by a team led by C. Walton Lillehei at the University of Minnesota in 1954 to an 11-year-old boy. Total improvement in infants has been successful from 1981, with studies showing that it has a relatively low mortality rate.
The total improvement of tetralogy of Fallot initially carries a high risk of death, but this risk has declined over the years. Surgery is now often performed in infants aged one year or younger with perioperative mortality less than 5%. Open heart surgery is designed to reduce right ventricular outflow stenosis with careful muscle resection and to repair VSD with a Gore-Tex or homograft patch. Additional reparative or reconstructive surgery may be performed in patients as required by their special heart anatomy.
Epidemiology
Tetralogy of Fallot occurs about 400 times per million live births and accounts for 7 to 10% of all congenital heart defects.
Prognosis
Untreated tetralogy of Fallot results in progressive right ventricular hypertrophy due to increased resistance caused by narrowing of the lungs. It develops into heart failure that begins in the right ventricle and often leads to left heart failure and dilated cardiomyopathy. The mortality rate depends on the severity of tetralogy of Fallot. If left untreated, TOF carries a 35% mortality rate in the first year of life, and a 50% mortality rate in the first three years of life. Untreated TOF also causes delayed growth and development, including delayed puberty.
Patients who have undergone a total tetralogy of Fallot repair surgery have improved hemodynamics and often have good heart function until very well after surgery with some no exercise intolerance (New York Heart Association Class I-II). The success of surgery and long-term outcomes depends largely on the patient's special anatomy and the skills and experience of the surgeon with this type of improvement.
Ninety percent of people with total improvement as a baby develops progressive pulmonary valves later in life. It is recommended that they follow-up at the center of specialized adult congenital heart disease.
Famous cases
- Shaun White, a professional snowboarder and skateboarder of the United States
- Beau Casson, Australian cricketer
- Dennis McEldowney, author and publisher of New Zealand
- Max Page, Volkswagen "Little Darth Vader" from the 2011 Super Bowl ad
- Billy Kimmel, the son of Jimmy Kimmel's talk show host; Billy's diagnosis makes Kimmel discuss access to health care at his show Jimmy Kimmel Live!
See also
- Trilogy of Fallot
References
External links
- What is Tetralogy of Fallot? at the National Institute of Health
- Understand your child's heart: Tetralogy of Fallot; by the British Heart Foundation
- 3-D Interactive Animation from Tetralogy Improvement Fallot - Stanford Children's Health
Source of the article : Wikipedia
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