One of the commonest presenting complain is failure to thrive and this results from difficulty in feeding due to dyspnea. Infants typically develop cyanosis and the severity is related to the degree of stenosis [7]. Sometimes these infants only develop these signs when they cry or feed in a phenomenon known as Tet spells. Older children with this condition squat a lot as squatting increases pulmonary blood flow by increasing peripheral vascular resistance. Dyspnea on exertion worsens with age and older children may rupture some bronchial collaterals which will cause hemoptysis [8].

Physical exam will reveal a small for age baby, cyanosis, finger clubbing in older children, heart murmurs typically a systolic ejection murmur, scoliosis, bulging left hemithorax, palpable right ventricle and retinal engorgement.

• Atrial Septal Defect

  with or without an associated inlet (AV septal type) ventricular septal defect... read more, atrial septal defect Atrial Septal Defect (ASD) An atrial septal defect (ASD) is an opening in the interatrial septum, causing a left-to-right shunt and volume [msdmanuals.com]

  At surgery the patient was found to have a complete atrioventricular septal defect in addition to these anomalies. Complete anatomical correction was achieved through the right atrial approach. [ncbi.nlm.nih.gov]

  Do you have a child between 30 days and 17 years old who will have elective surgery to close an atrial septal defect? This study tests a tool that allows surgeons to tell the difference between various types of heart tissue and avoid injury. [nhlbi.nih.gov]

• Cyanotic Congenital Heart Disease

  November 2020. doi:10.25373/ctsnet.13198286 Tetralogy of Fallot (TOF) is one of the most common cyanotic congenital heart diseases. [ctsnet.org]

• Congestive Heart Failure

  Drugs that help to remove excess fluid from the body (diuretics), dietary salt restriction, and bed rest may be effective in treating congestive heart failure. [rarediseases.org]

  Finally, for patients with mild disease, with so‐called “pink tetralogy” due to the lack of cyanosis, their presentation may consist of signs and symptoms of congestive heart failure due to the left‐to‐right shunting across the VSD and subsequent pulmonary [pedclerk.bsd.uchicago.edu]

  Major factors were congestive heart failure and schizophrenia in one patient (#17 in Table 1, died suddenly) and schizophrenia in the other (#15 in Table 1, with repeated admissions). [nature.com]

  In addition, this approach avoids the risks of pulmonary artery shunting with its inherent risks, namely shunt thrombosis, congestive heart failure, pulmonary artery distortion, or pulmonary vascular disease. [circ.ahajournals.org]

• Hypoxemia

  Chronic hypoxemia-induced secondary polycythemia and the consequent increase in blood hyperviscosity predisposed this patient to PE. This case reminds us of the similarity in clinical presentation between PE and tet spells. [ncbi.nlm.nih.gov]

  If hypoxemia is severe, correcting the resulting acidosis may be necessary with sodium bicarbonate. Subspecialty Related Media Keyword history 89%/2012 82%/2009 See Also: Sources PubMed [openanesthesia.org]

  The blood leaving the heart has less oxygen than is needed by the organs and tissues of the body, a condition called hypoxemia. [webmd.com]

  Major limiting factors in these 19 patients in Grade 2 included mental retardation in 13, deafness in 4, hypoxemia in 3, club feet in 2, schizophrenia in 2, and depression in 1 patient. [nature.com]

• Hypothermia

  Operative technique All patients underwent surgery with the use of conventional cardiopulmonary bypass with membrane oxygenators and moderate hypothermia (25º). [bjcvs.org]

  Correct any underlying causes such as arrhythmia, hypothermia, hypoglycaemia. Despite the initial measures describe in Q6, the baby remains distressed and profoundly cyanotic. Q7. Describe the further management of a prolonged episode. [lifeinthefastlane.com]

  The surgical technique has been reported previously. 7 Operative management used deep hypothermia (18°C to 25°C) with either low-flow cardiopulmonary bypass or circulatory arrest. [circ.ahajournals.org]

  This time, Souttar's technique was widely adopted, with some modifications.[6][7] The first successful intracardiac correction of a congenital heart defect using hypothermia was performed by lead surgeon Dr. F. John Lewis[10][11] (Dr. C. [en.wikipedia.org]

  Consensus definitions of sepsis from 1989, 1992, 2003, and 2016 Sepsis syndrome definition (1989)  Sepsis syndrome criteria   Hypothermia < 35.5℃ or hyperthermia > 38.3℃   Tachycardia > 90 beats/min   Tachypnea > 20 breaths/min   Clinical evidence of [ekjm.org]

• Respiratory Distress

  Fetuses with this combined condition who survive through birth typically need intervention in infancy or early childhood because of respiratory distress, heart failure, or failure to thrive. [ncbi.nlm.nih.gov]

  Discontinuation of life: ethical and legal issues -- Respiratory complications: acute respiratory distress syndrome, chylothorax, diaphragmatic palsy, and functional and respiratory physiotherapy -- Gastrointestinal complications: necrotizing enterocolitis [worldcat.org]

  The past few days he has had poor feeding and recurrent episodes of respiratory distress associated with ‘turning blue’. He was diagnosed with Tetralogy of Fallot antenatally and was born at term (a normal vaginal birth). [lifeinthefastlane.com]

  distress or heart failure. [physio-pedia.com]

• Tachypnea

  The tachypnea is due to pulmonary overcirculation, resulting from left to right flow across the ventricular septal defect. [clinicaladvisor.com]

  Consensus definitions of sepsis from 1989, 1992, 2003, and 2016 Sepsis syndrome definition (1989)  Sepsis syndrome criteria   Hypothermia < 35.5℃ or hyperthermia > 38.3℃   Tachycardia > 90 beats/min   Tachypnea > 20 breaths/min   Clinical evidence of [ekjm.org]

  Symptoms include stridor, cyanosis and tachypnea and should lead to immediate admittance and treatment. Systemic corticosteroids are used in patients with risk of airway compromise and show significant results within 12–36 h if treated aggressively. [bmcfampract.biomedcentral.com]

• Clubbed Finger

  The symptoms of ToF may be present at birth or shortly afterward, and include: Blueish discoloration of skin – “blue baby” Clubbed fingers Problems with eating Failure to gain weight Developmental delays Episodes of passing out What are “tet spells?” [agileglobalhealth.com]

  They include: a bluish skin color clubbed fingers, or growths of skin and bone around the fingernails problems with eating failure to gain weight developmental delays or problems episodes of passing out The exact cause of TOF is unknown, but several risk [healthline.com]

• Regurgitation

  Patients after correction of ToF usually develop residual defects such as pulmonary regurgitation or stenosis of variable severity. However, the importance of different hemodynamic parameters and their impact on exercise capacity is unclear. [ncbi.nlm.nih.gov]

• Heart Disease

  disease and has a prevalence of 10% of all congenital heart diseases. [scielo.br]

  KEYWORDS: Cardiopulmonary exercise testing; Congenital heart disease; Pulmonary valve replacement; Tetralogy of Fallot [ncbi.nlm.nih.gov]

  Some examples of cardiovascular diseases include ischemic heart disease, heart valve disease, cardiomyopathies, peripheral artery disease, congenital heart disease, and vascular disease of the kidneys. This study is located in Bethesda, Maryland. [nhlbi.nih.gov]

• Cyanosis

  This leads to cyanosis (a bluish-purple color to the skin). [ufhealth.org]

  The cyanosis occurs because oxygen-poor blood is darker and has a blue color, so that the lips and skin appear blue. The extent of cyanosis is dependent on the amount of narrowing of the pulmonary valve and right ventricular outflow tract. [cincinnatichildrens.org]

  Definitions of tetralogy of Fallot 1 n a congenital heart defect producing cyanosis; characterized by four symptoms: pulmonary stenosis and ventricular septal defect and malposition of the aorta over both ventricles and hypertrophy of the right ventricle [vocabulary.com]

  The term cyanosis means a bluish discoloration of the skin. The cause of cyanosis is a lower than normal blood oxygen level. [pediatricheartspecialists.com]

  Symptoms include cyanosis, dyspnea with feeding, poor growth, and hypercyanotic "tet" spells (sudden, potentially lethal episodes of severe cyanosis). [msdmanuals.com]

• Hypotension

  In patients with unrepaired tetralogy of Fallot, oxytocic drugs such as oxytocin, which induces vasodilation and arterial hypotension, should be avoided. [heartdiseaseandpregnancy.com]

  Adverse effects from losartan are usually limited and consist of dizziness due to hypotension, renal impairment, hyperkalemia and liver impairment. [clinicaltrials.gov]

  ‘Tet spells’ may be spontaneous or precipitated by events associated with decreased systemic vascular resistance, such as: tachycardia hypotension exertion during feeding defecation crying This leads to a vicious cycle, that is usually self-limiting [lifeinthefastlane.com]

  The long half-life, and potential side effects, such as hypotension and cardiac dysfunction, of beta blockers precludes their routine use in the emergency situation. [ncbi.nlm.nih.gov]

  Inflammatroy variables    Leukocytosis (WBC count > 12,000/μL)    Leukopenia (WBC count < 4,000/μL)    Normal WBC count with > 10% immature forms    Plasma C-reactive protein increase    Plasma procalcitonin increase   Hemodynamic variables    Arterial hypotension [ekjm.org]

• Single S2

  […] with knee-chest position, oxygen, or morphine usual onset is around 2-6 months of age Physical exam systolic thrill along the left sternal border loud and harsh systolic ejection murmur on the upper sternal border may or may not have a preceding click single [step1.medbullets.com]

  Single S2 - pulmonary valve closure not heard. Systolic ejection murmur - varies in intensity inversely with the degree of RVOT obstruction. Cyanotic patients have greater obstruction and a softer murmur. [patient.info]

  There is also a loud and single S2 in TOF. [lifeinthefastlane.com]

  Patients will have a normal S1 and possibly a single S2 due to diminished P2 component. Click on the icon below to hear the murmur of TOF: Cyanosis: If patients are cyanotic, this is most commonly seen on the lips or nail beds. [pedclerk.bsd.uchicago.edu]

• Agitation

  Tet spells can be precipitated by a number of things, including dehydration, agitation, or fever. Some children may have spells in the absence of any identifiable cause. [pediatricheartspecialists.com]

  […] crying Heart murmur Fainting An abnormal, rounded shape of the nail bed in the fingers and toes (clubbing) Tet spells Sometimes, babies who have tetralogy of Fallot will suddenly develop deep blue skin, nails and lips after crying or feeding, or when agitated [mayoclinic.org]

  Poor feeding, breathlessness and agitation. Dyspnoea on exertion (usually after prolonged crying) is common. Squatting to rest whilst exercising is characteristic of a right-to-left shunt and presents in an older child. [patient.info]

Laboratory investigations include blood tests to check the hemoglobin and hematocrit which will be elevated; arterial blood gas to show oxygen saturation, pH and partial pressure of carbon dioxide.

Radiologic studies include chest X-rays which shows a characteristic boot shaped heart, signifying right ventricular hypertrophy. MRI is also valuable as it shows vessels in addition to the heart. An echocardiogram is the mainstay in diagnosis as it demonstrates the four anatomical defects. Electrocardiograms can also be done to examine the electrical activity of the heart [9].

• P Pulmonale

  Example 2 Right axis deviation (+150 degrees) P pulmonale (P wave in lead II > 2.5 mm) Incomplete RBBB Right ventricular strain pattern with T-wave inversion and ST depression in the right precordial (V1-3) and inferior (II, III, aVF) leads. [litfl.com]

• Right Atrial Hypertrophy

  A right aortic arch is present in 25%. ECG shows right ventricular hypertrophy and may also show right atrial hypertrophy. [msdmanuals.com]

The definitive treatment of this condition is surgical correction and this is best done in the first year of life. The surgery aims to close the ventricular septal defect with the use of a patch or homograft, resect the infundibular stenosis and relieve right ventricular outflow tract obstruction. These procedures are usually done under cardiopulmonary bypass.

The two common surgical procedures are Blalock-Taussig shunt which is palliative and intracardiac repair which is definitive.

Before surgery however, medications like prostaglandins may be necessary to keep the ductus arteriosus patent. Other associated acute complications are also managed like diuretics and digitalis for heart failure [10].

The prognosis is favorable for patients who undergo surgical repair with over 90% of 20-year survival rate. The advancement of surgical techniques has seen a drastic reduction in the number of deaths. There is however a high mortality rate in those who do not undergo surgical repair. It is estimated that 50% of them would have died by the age of 6 years. Less than 20% of them reach the age of 10 years and less than half of those live beyond 20 years. Patients who survive beyond this point develop congestive cardiac failure [6].

The cause of tetralogy of Fallot, like most congenital heart diseases, is unknown. Studies however suggest a multifactorial etiology. There are prenatal factors that have been associated with an increased risk of developing tetralogy of Fallot. These include viral illnesses during pregnancy e.g rubella, mothers age greater than 40 years, maternal alcohol use, diabetes, and poor prenatal nutrition. Children born with Down syndrome and fetal hydantoin syndrome also have an increased risk of suffering from tetralogy of Fallot [2].

It is estimated that tetralogy of Fallot is responsible for 10% of all cases of congenital heart disease. It has an incidence of up to 6 in 100,000 live births and it is the most common cause of cyanotic congenital heart disease. It is responsible for approximately 33% of all congenital heart diseases in patients younger than 15 years [3].

It affects males more than females and the cases are usually sporadic with no familial association. It is associated with other extracardiac defects like hypospadias, cleft lip and palate, and craniofacial and skeletal anomalies.

The initial defect is pulmonary infundibular stenosis which causes narrowing of the outflow tract, which limits the amount of deoxygenated blood that goes into pulmonary circulation. In response to this, the right ventricle increases the pressure with which it pumps blood into the lungs. This increased workload will lead to hypertrophy of the muscles of the right ventricle. There is also a ventricular septal defect which allows shunting of blood between both ventricles. In VSD, due to the hypertrophy of the right ventricle, the shunting is from right to left i.e. deoxygenated to oxygenated. This blood which is part deoxygenated is then pumped though the overriding aorta to the systemic circulation leading to the cyanosis that is manifested [4].

In different individuals, there is slight anatomical variation in the degree of anomalies. The severity of the outflow tract varies between patients and is responsible for severity of symptoms. In patients with smaller obstructions, as in patients with isolated VSD, the shunt is left to right and this allows the blood to go into the lungs where it can get reoxygenated [5].

There are no known guidelines for preventing this condition. Some steps may however be taken to prevent some preventable risk factors like maternal alcohol use.

Tetralogy of Fallot is a common congenital heart disorder. It is a cyanotic heart disease and is the most common cause of blue baby syndrome, a common name for methemoglobinemia in newborns. Although it comprises of four main anomalies, there could be other defects and they are all together responsible for the myriad of symptoms seen in patients with tetralogy of Fallot [1].

Definition: Tetralogy of Fallot (TOF) is a congenital heart defect, the baby is born with it. It is made up of 4 different defects and the severity of these defects determine the severity of the symptoms in the child.

Cause: There is no known cause. However, some maternal factors have been associated with an increased risk of the child developing TOF. They include, viral infections in pregnancy, maternal diabetes, maternal age over 40, maternal alcohol use, and poor prenatal nutrition.

Symptoms: The most common symptom us the child’s inability to feed. The growth will also be stunted as a result. There might also be blue discoloration especially of the lips and mouth (blue baby syndrome) and sometimes, this discoloration is only noticed when the child feeds or cries. Older children tend to squat a lot. There may be also be difficulty in breathing after a little exercise and coughing up blood.

Diagnosis: A series of blood tests will be required to check the blood levels including its gases. Some imaging tests like X-rays and echocardiograms will also be done to look at the size of the heart and the direction of blood flow within it.

Treatment: The main treatment is corrective surgery. This is preferably done in the first year of life and ideally not later than 2 years. Medications are given before surgery to manage circulation and also treat acute attacks.

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3. Perloff JK. The Clinical Recognition of Congenital Heart Disease, 4th, WB Saunders, Philadelphia 1994.
4. Anderson RH, Weinberg PM. The clinical anatomy of tetralogy of fallot. Cardiol Young. Feb 2005;15 Suppl 1:38-47.
5. Flanagan MF, Foran RB, Van Praagh R, et al. Tetralogy of Fallot with obstruction of the ventricular septal defect: spectrum of echocardiographic findings. J Am Coll Cardiol 1988; 11:386.
6. Hövels-Gürich HH, Konrad K, Skorzenski D, Minkenberg R, Herpertz-Dahlmann B, Messmer BJ, et al. Long-term behavior and quality of life after corrective cardiac surgery in infancy for tetralogy of Fallot or ventricular septal defect. Pediatr Cardiol. Sep-Oct 2007;28(5):346-54.
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8. Miatton M, De Wolf D, François K, Thiery E, Vingerhoets G. Intellectual, neuropsychological, and behavioral functioning in children with tetralogy of Fallot. J Thorac Cardiovasc Surg. Feb 2007;133(2):449-55.
9. Srivastava S, Salem Y, Chatterjee S, Helen Ko H, Lai WW, Parness IA, et al. Echocardiographic Myocardial Deformation Evaluation of Right Ventricular Function in Comparison with CMRI in Repaired Tetralogy of Fallot: A Cross-Sectional and Longitudinal Validation Study. Echocardiography. Feb 2013;30(2):196-202.
10. Aboulhosn J, Child JS. Management after childhood repair of tetralogy of fallot. Curr Treat Options Cardiovasc Med. Dec 2006;8(6):474-83.