MY ROUNDS -CCHD- TOF

• 11/2 yr old child presented with not growing enough and  squatting spells . she didnt have any serious illness in the past.mother says child gets fast breathing which is easily relieved by sitting on the floor o/e  moderate malnutrition, central cyanosis ,pan digital clubbing  ,apex 4th left intercostal space, prominent epigastric pulsation +, s1 normal s2 single,3/6 systolic murmur lt upper sternal border   what is your diagnosis? low flow cchd with h/o spells and finding are most likely due tof physiology
• what do you understand by fallot’s physiology?
• The term tetralogy of Fallot is often used as an umbrella diagnosis that includes those with abnormal ventriculoarterial connections (tetralogy of Fallot with double-outlet right ventricle), and particular associated features (e.g., tetralogy of Fallot with pulmonary atresia, with and without major aortopulmonary collateral arteries, tetralogy of Fallot with absent pulmonary valve syndrome).
• what is the defect in tof?
• The fundamental abnormality that characterizes the disease is anterior and cephalad deviation of the outlet septum. The secondary effects of this singular abnormality are the creation of a ventricular septal defect (VSD), aortic override, and right ventricular outflow tract obstruction and hypertrophy
• The hallmark of the right ventricular outflow tract obstruction in tetralogy of Fallot is infundibular stenosis. This is due to many factors, the most important of which is the anterior cephalad deviation of the outlet septum
• The VSD in patients with tetralogy of Fallot is usually large and unrestrictive. In most patients, the VSD is perimembranous, with the central fibrous body forming the inferior border and the conduction system running adjacent. In approximately 20% of patients there is a muscular posteroinferior rim Controversy remains as to whether tetralogy of Fallot can coexist with a doubly committed VSD. The hallmark of the doubly committed VSD is fibrous continuity of the leaflets of the aortic and pulmonary valves The degree of aortic override varies considerably. It should be remembered that tetralogy of Fallot is a diagnosis, whereas double-outlet right ventricle defines a ventriculo-arterial connection, and the two may coexist. If the degree of override is >50%, then the designation of tetralogy of Fallot with double-outlet right ventricle may be made.
• what are the associations?
• Atrial communications are fairly frequent and usually at the fossa ovalis as either a patent foramen ovale ormore rarely a true secundum atrial septal defect.
• Approximately 25% of patients have a right-sided aortic arch that can alter the approach to a palliative shunt. Tetralogy of Fallot may coexist with atrioventricular septal defect (AVSD), and should be especially considered in children with Down syndrome. A primum component may not be present in these, and under such circumstances the clue to the presence of an AVSD is a trileaflet left atrioventricular valve on echocardiographic imaging.
• Straddling atrioventricular valve is a rare associated feature.
• Abnormalities of the coronary arteries, such as the left anterior descending coronary artery arising from the right coronary artery, occur in ~4% of patients This anomaly is exceedingly important to recognize, as the left anterior descending coronary then crosses the right ventricular outflow tract, and failure to identify this vessel can result in its inadvertent transection during outflow tract repair.
• Occasionally, significant systemic-to-pulmonary collaterals are present even when the outflow tract is patent. This is commonly associated with discontinuous branch pulmonary arteries or bilaterally diminutive central pulmonary arteries
• which all conditions are associated with tof?

            Trisomy 21 (Down)

           Velocardiofacial (Shprintzen)

                   2 2q11 deletion or CATCH-22a syndrome

          Goldenhars

         Thrombocytopenia absent radius

                CHARGEb

             VATERc/VACTERLd

        Fetal alcohol

       Pierre Robin

        Associated organ abnormalities

      Include tracheoesophageal fistula, imperforate anus, hydrocephalus,omphalocele

• what is the recurrence risk?
• The recurrence risk for tetralogy of Fallot in families with one affected child is probably 2–5%. For mothers who have tetralogy of Fallot, the transmission risk for congenital heart disease in offspring is probably 5–10%; for fathers with tetralogy of Fallot, the transmission risk is ≤ 5 [12].
• what is the genetics of tof?
• A microdeletion of chromosome 22q11 may be present in 20–30% of patients with tetralogy of Fallot, with higher values if there is also pulmonary atresia  [8–11]. This same chromosome is involved in DiGeorge syndrome and abnormalities con sidered previously such as the velocardiofacial syndrome (Shprintzen syndrome).
• what are the physical examination findings?
• The clinical presentation of patients with tetralogy of Fallot depends primarily on the degree of right ventricular outflow tract obstruction. Presentation can range from a profoundly cyanotic newborn with ductus-dependent pulmonary circulation to an asymptomatic child with adequate pulmonary flow presenting with a murmur. Because of this wide spectrum of presentation, the physical findings vary widely. Relatively few are cyanotic at birth, but most become cyanotic by Inspection often reveals an apparently healthy infant or child, although major extracardiac anomalies, such ashypospadias, cleft lip and palate, pectus carinatum, and other bony abnormalities, can be seen [22]. Cyanosis is present to varying degrees and can be best appreciated in the mucous membranes or nail beds. The degree of cyanosis depends not only on the amount of right-to-left intracardiac shunting, but also on the hemoglobin concentration. To appreciate cyanosis, there must be approximately 3–5 g dl−1 of desaturated hemoglobin in arterial blood; this quantity is easier to achieve at higher hemoglobin concentrations.Therefore, the relatively erythrocytotic neonate may appear more cyanotic shortly after birth than at a few months of age during the period of normal postnatal physiologic anemia. The level of cyanosis in a given individual also varies with activity and metabolic rate. Fever and exercise increase the level of cyanosis, both from the decreased systemic vascular resistance and from a resultant increase in right-to-leftshunting, and also increased oxygen consumption by the tissues, with a resultant fall in mixed venous saturation 3 months of age
• Hypoxic spells, variously called paroxysmal hyperpnea, syncopal attacks, hypoxic or hypercyanotic spells, are dramatic and alarming features of Fallot’s tetralogy.94–96
• A typical spell begins with a progressive increase in the rate and depth of breathing and culminates in paroxysmal hyperpnea, deepening cyanosis, limpness, syncope, and occasionally convulsions, cerebrovascular accidents, and death.95,96 Electroencephalographic abnormalities during an hypoxic spell are similar to those of hypoxic episodes of other causes.97 Peak incidence is between the second and sixth month of life, with an occasional spell as early asthe first month but comparatively few spells after age 2 years, and only rarely in adults.98 Spells in infants are typically initiated by the stress of feeding, crying, or a bowel movement, particularly after awakening from a long deep sleep.94,95 However, attacks sometimes occur without an apparent precipitating cause, especially in deeply cyanotic infants, although spells are not necessarily related to the degree of cyanosis.95 Spells were originally attributed to infundibular contraction caused by sympathetic stimulation, which was believed to divert right ventricular blood into the aorta,96 but occurrence in patients with pulmonary atresia argued against this theory.
• It is now believed that vulnerable respiratory control mechanisms, which are especially sensitive after prolonged deep sleep, react to the sudden increase in cardiac output provoked by feeding, crying, or straining, by initiating the following vicious cycle.94,95 As heart rate and cardiac output increase, venous return increases in the face of fixed obstruction to right ventricular outflow, so the right-to-left shunt increases. Infundibular contraction reinforces this pattern but does not initiate it. The increased right-to-left shunt causes a fall in systemicarterial pO2 and pH and a rise in pCO2, a blood gas composition to which a sleep-sensitive respiratory center and carotid body overreact, provoking hyperpnoea, which in turn further increases the cardiac output and perpetuates the cycle. Supraventricular tachycardia and rapid atrial pacing initiate spells by inducing infundibular narrowing,which increases the right-to-left shunt.99
• Clubbing of the fingers and toes develops in patients with chronic cyanosis. Although usually seen in older patients, it can develop in infancy. Clubbing resolves with restoration of normal systemic oxygen saturation after complete repair.In a preoperative patient, the jugular venous pulsations are usually normal, although difficult to evaluate in infants. The right ventricle remains relatively compliant with normal or only mildly elevated diastolic pressures, and significant tricuspid regurgitation is uncommon. Thus the a and v waves in the jugular pulse are usually normal.
• The peripheral pulses are usually normal, and accentuated pulses should suggest a large patent ductus arteriosus or significant aorticopulmonary collateral arteries. The precordial impulse can be normal, but usually a right ventricular parasternal lift can be appreciated. Hepatomegaly is unusual.
• Auscultation reveals a normal first sound and a single second (aortic) sound that is loudest at the mid-left sternal border. With significant right ventricular outflow tract obstruction and low pulmonary arterial pressures, the pulmonary component of the second heart sound is usually inaudible. Occasionally, if the outflow tract obstruction is not severe, splitting of the second heart sound can be appreciated. Third and fourth heart sounds are uncommon. An early systolic ejection click can be heard at the left mid-touppersternal border caused by the dilated ascending aortaand the increased systemic blood flow.
• The VSD is large and unrestrictive, and the right-to-left shunt does not produce a murmur. The murmur is classically described as a low-pitched, systolic crescendo/decrescendo ejection murmur best heard at the left mid-to-upper sternal border with radiation to the back. However, it is not uncommonfor the murmur to resemble that of plateau quality, bestheard at the left mid-to-lower sternal border. In thesepatients, one needs to rely on other physical findings such ascyanosis or a single second heart sound to suspect the diagnosisof tetralogy of Fallot. In an acyanotic neonate, themurmur caused by the left-to-right shunt across a small VSDis difficult to separate from the murmur of infundibular stenosis,and it is easy to misdiagnose the infant. The distinctioncan be made clinically in most infants; a neonate with tetralogy of Fallot will have a forceful right ventricular lift andusually a loud and single second heart sound.
• Unlike pulmonary valve stenosis with an intact ventricularseptum in which the intensity and length of the murmurincrease with increasing obstruction, the murmur in tetralogy of Fallot diminishes with worsening obstruction. This isbecause the intensity of the murmur is related not only tothe degree of obstruction, but also to the amount of flow across the obstruction. In tetralogy of Fallot, as the right ventricularoutflow tract obstruction progresses, the right ventricularsystolic output is preferentially shunted across the VSD and into the systemic circulation. The flow across theright ventricular outflow tract is reduced, resulting in a softermurmur. This phenomenon is best demonstrated by a tetralogy spell, during which the outflow obstruction can becomeso severe that the murmur becomes inaudible while thepatient becomes progressively more cyanotic.
• Diastolic murmurs are rarely heard in an unoperated patient with tetralogy of Fallot. A continuous murmur in theleft infraclavicular region suggests a patent arterial duct.Very rarely a right-sided duct results in a continuous murmurin the right infraclavicular region. Continuous murmursheard in the posterior lung fields raise concern about significant aorticopulmonary collaterals. An early diastolic murmuralong the left sternal border is one of the hallmarkfindings in tetralogy of Fallot with absent pulmonary valve The murmur in patients with unrepaired tetralogy of Fallot is generated by the right ventricular outflow obstruction.
• what are the findings post operatively?
• The physical examination in a postoperative patient depends on the type of procedure performed. Palliation witha systemic shunt produces a continuous murmur similar to a patent duct. Appreciation of this murmur in the immediatepostoperative period may be difficult because of a ventilatoror other competing noises. In this situation, auscultatingwith the bell of the stethoscope briefly applied to the end ofthe endotracheal tube often allows appreciation of the murmurbecause of the proximity of the shunt to the bronchi.
• After complete repair of tetralogy of Fallot, a variety ofphysical findings can be found. On inspection, cyanosisshould be absent and clubbing should resolve with time. Iftricuspid regurgitation has developed, a prominent v wavecan be appreciated in the jugular pulsations. Depending onthe degree of pulmonary insufficiency and residual outflowtract obstruction, one can palpate a right ventricular parasternallift. On auscultation, the first heart sound remainsnormal. The second heart sound frequently remains single.When, however, the pulmonary valve is partially or completelyintact, or a valved conduit is used, the second heartsound can split normally with respiration or, if there is right bundle branch block, is widely split. It varies with respiration,but the split persists during expiration. Frequently, anejection systolic murmur is present at the left mid-to-upper sternal border from mild residual right ventricular outflowobstruction. A louder ejection murmur should raise concern about more significant obstruction. During follow-up, long systolic ejection murmurs that are best appreciated at the leftupper sternal border or in either the axilla or the back indicatebranch pulmonary artery stenosis and usually warrant further investigation. A blowing, pansystolic murmur from asmall residual VSD or tricuspid regurgitation may be heardat the left lower sternal border. A low-pitched delayed diastolic decrescendo murmur at the mid-left sternal border is commonand results from pulmonary regurgitation caused byrelief of the right ventricular outflow obstruction. This diastolic murmur should be differentiated from the highpitchedearly diastolic decrescendo murmur at the left sternal border generated from aortic regurgitation. This latter murmur is not expected unless patients have had longstandingpulmonary atresia with a dilated aortic root, and italso warrants further evaluation. Most patients with satisfactorysurgical results have soft systolic/diastolic to-and-fromurmurs of mild pulmonary stenosis and regurgitationalong the mid-to-upper left sternal border
• what are the mechanism involved in  fallots spell?
• Five mechanisms are therefore involved in the pathogenesis of Fallot spells: (1) an acceleration in heart rate; (2) an increase in cardiac output and venous return; (3) an increase in right-to-left shunt; (4) vulnerable respiratory control centers; and (5) infundibular contraction
•   Manual compression of the abdominal aorta can abort a spell by decreasing cardiac output and venous return.Squattingfor relief of dyspnea is a time-honored hallmark of Fallot’s the preference for certain postures other than squatting, namely, the knee-chest position, lying down, or sitting with legs drawn underneath 3 Parents may hold their breathless infant upright with its legs flexed against its abdomen ). Young adults cross their legs during quiet standing or sitting, a relatively ineffective variation. Habitual squatters assume the position effortlessly (see ). The mechanisms by which squatting exerts its beneficial effects are as follows.(1) Quiet standing after exercise-induced peripheral vasodilation predisposes to orthostatic hypotension and faintness, a tendency that is exaggerated in hypoxemic patients. Squatting counteracts orthostatic hypotension and diminishes or prevents postexertion orthostatic faintness. 102,104 (2) Squatting increases systemic vascular resistance,diverts right ventricular blood into the pulmonary circulation, and increases the amount of oxygenated blood entering the left side of the heart.
• How the dx is made?
• An acyanotic neonate with tetralogy of Fallot must bedistinguished from an infant with a simple VSD (see earlier).If cyanotic, the infant needs to be distinguished from infants with other forms of cyanotic heart disease with pulmonicstenosis, including double-outlet right entricle, transpositionof the great arteries and a VSD, single ventricle, and tricuspidatresia with normally related great essels. Each of these has distinctive echocardiographic features. Tricuspid atresia hasa characteristic electrocardiogram, and all these entities aremuch less common than tetralogy of FallotThe diagnosis of tetralogy of Fallot is aided by electrocardiographyand chest radiography.
• The electrocardiogram isuseful because it always shows right ventricular hypertrophy.In addition, right atrial enlargement and right-axis deviation are also usually present. Left-axis deviation should raise thepossibility of an associated atrioventricular septal defect.Biventricular hypertrophy may be seen in patients who haveso-called pink tetralogy with increased pulmonary blood flow.
• In a neonate, the first or only sign of right ventricularhypertrophy can be an upright T wave in lead Vi or V4R after3 days of age. As the child gets older, typical signs of right ventricular hypertrophy are present: right axis deviation,increased anterior (large R waves, or an rR’ pattern or a QRpattern in V1) and rightward (large S in V6) forces, and upright T waves in V1.The chest radiograph of the typical patient shows normal visceroatrial situs, a tilted-up apex, a concave main pulmonaryartery segment, and normal to decreased pulmonaryvascularity. The heart is usually not enlarged
• A right-sided aortic arch can be identified in ~25% of patientswith tetralogy of Fallot.
• Patients with tetralogy of Fallot and absent pulmonaryvalve usually have an enlarged heart and markedly enlargedmain, right, and left pulmonary arteries. Frequently, lunghyperinflation and tracheobronchial compression occur The electrocardiogram and chest radiograph in patientswith co-existing pulmonary atresia are usually identical with those found in patients with simple tetralogy of Fallot.
• The rare patient with increased pulmonary blood flow caused by a large ductus or a large collateral can show an enlarged heart with increased vascularity and hyperinflated lung fields.
• what is the role of Echocardiography?
• Two-dimensional echocardiography and Doppler echocardiographyusually completely define the diagnosis of tetralogyof Fallot, both prenatally and postnatally. Tetralogy of Fallothas been diagnosed as early as 14 weeks’ gestation usingtransvaginal ultrasound.[24] This lesion, however, continuesto evolve through mid and late gestation [25–28]. Serial studies of the embryo and fetus with tetralogy of Fallot areessential in preparing families for the postnatal course ofthese infants.
• Early in gestation, the large malalignment perimembranous VSD and aortic override can be seen.Anterior deviation of the outlet septum is also apparent. Bymid-gestation, there is considerable variation in the size ofthe main pulmonary artery, ranging from normal to ypoplastic. The branch pulmonary arteries are usually ofnormal size. In the second half of pregnancy, patients with more severe forms of tetralogy of Fallot demonstrate abnormal growth of the main and branch pulmonaryarteries, resulting in progressive hypoplasia, and even in loss of anterograde flow. The aorta may be normal or increasedin size during mid-gestation, with an increased rate of growthcompared with a normal fetus, resulting in the large ascending aorta characteristic of this lesion.The likelihood of prenatal detection of tetralogy of Fallotduring ultrasound screening depends on both the severity of the lesion and the experience of the ultrasonographer
• .Although the VSD should be seen in the four-chamber viewduring obstetric screening this lesion has been missed during screening examinations that rely on this viewalone. Visualization of the outflow tract views increases thelikelihood of prenatal diagnosis of tetralogy of Fallot, although fetuses with a milder forms of this anomaly haverelatively normal outflow tract views at mid-gestation. Inlarge prenatal echocardiographic series using multiple imaging planes for comprehensive evaluation, tetralogy ofFallot is one of the more commonly diagnosed lesions, accounting for 4–28% of identified congenital cardiacanomalies. The subset of fetuses with tetralogy of Fallot with kabsent pulmonary valve are disproportionately represented in prenatal series, almost certainly because the dilated rightventricle and pulmonary arterial tree that characterize thislesion result in their more frequent identification.
• During prenatal echocardiographic examination, thecharacteristic VSD can be demonstrated in the long-axis,sagittal, and four-chamber views. Doppler interrogation of the VSD should be included to rule out the rare restrictiveVSD. Short-axis and sagittal views can be used to delineatethe right ventricular outflow tract and main and branch pulmonary arteries. Although Doppler interrogation of theright ventricular outflow tract is important in assessing theseverity of obstruction postnatally, flow velocities in the parallel fetal circulation are usually in the normal range [28,29].Doppler interrogation and Doppler color flow mapping can,however, readily demonstrate the to-and-fro flow patternseen in fetuses with absent pulmonary valve. Sagittalimaging also allows examination of the arterial duct and aortic arch. Fetuses with more severe right ventricularoutflow tract obstruction have retrograde ductal flow in utero[25,30]. Other evidence of the severe right ventricularoutflow tract obstruction includes significant hypoplasia ofthe main and branch pulmonary arteries and poor growth ofthe pulmonary arterial tree during the course of serial examinations.As with all prenatal diagnoses of congenital heart disease, fetuses with tetralogy of Fallot should undergo assessment offetal karyotype and comprehensive ultrasound examinationto rule out extracardiac anomalies. Families should be counseled regarding the in utero evaluation of this lesion andthe need for serial evaluations.
• All fetuses with the prenataldiagnosis of tetralogy for Fallot should be delivered at a tertiary care center with appropriate support staff forevaluating and managing these infants.
• Postnatally, complete echocardiographic evaluation mustinclude examination of all aspects of anatomy important tomanagement. At most institutions, echocardiography is the primary method of evaluation before operation, with cardiaccatheterization reserved for those patients with specificunresolved questions after echocardiographic examination. Elements of anatomy that must be assessed include theanatomic type and boundaries of the VSD, the presence orabsence of multiple VSDs, the severity and level of right ventricular outflow tract obstruction, the anatomy of thepulmonary arteries, the anatomy of the aortic arch, thepcourse of the coronary arterial tree, and the presence ofassociated abnormalities.
• The large VSD present in this lesion can be imaged in multipleviews. Its relationship to the aorta, the mitral valve, and thelarge VSD can be seen in the long-axis view The relationship between the defect and the tricuspid valve canbe seen in the parasternal short-axis view, in which thepotential for extension as a doubly committed defect can also be assessed. The apical four-chamber view usually demonstratesthe continuity among the tricuspid, aortic, and mitralvalves and also allows assessment of the degree of aortic override. Caudal angulation of the transducer can be used toexamine the degree of posterior extension of the defect.The subcostal right oblique view is perhaps the most useful view to evaluate the VSD and outlet septum ).Here, the relationship between the tricuspid and aortic valvesin infants with a perimembranous defect is well seen. In the rare instances of obstruction of the VSD, the subcostalcoronal view allows demonstration of the abnormal or accessory tricuspid valve tissue obstructing the defect and ofpossible attachments to the infundibular septum [31,32].This abnormal tricuspid valve tissue can also be imaged in parasternal axis views.The levels of right ventricular outflow tract obstruction are best assessed in the parasternal short-axis and subcostalviews. The prominent septoparietal trabeculations can beseen intruding on the infundibular region in the subcostal coronal view. In the parasternal short-axis and subcostalsagittal views, the anterior and superior deviation of theinfundibular septum can be appreciated, and the abnormal pulmonary valve can be seen Measurements of the pulmonary valve annulus are importantin predicting the need for transannular patch

what is the Medical management?

• The medical management of a patient with tetralogy of Fallot depends on the clinical presentation. A cyanotic neonate who is duct dependent should be stabilized with prostaglandin E1 infusion.In an asymptomatic infant with adequate pulmonary flowand systemic saturation, no initial therapy may be necessary.This infant can be followed as an outpatient with close attention to growth, symptoms, and systemic saturation. Ifthe child develops significant cyanosis or reaches an appropriate size or age, repair can be performed electively.The development of tetralogy spells is an indication for early intervention.

• Medical management of hypercyanotic spells is directed towards improving pulmonary blood flow and sustaining mixed venous oxygen saturations (reducing systemic oxygen consumption). Parents should be educated to comfort the child while placing him or her in the knee–chest position to increase systemic afterload and force more blood flow across the pulmonary outflow tract.
•  In a hospital, the patient’s airway and breathing should be assessed, the patient placedin the knee–chest position, and 100% oxygen given. Sedation with morphine sulfate (0.1 mg kg−1) can be given intravenously (i.v.), or intramuscularly (i.m.) should an intravenous line not be available. Acidosis may develop and should be treated with bicarbonate. An intravenous fluid bolus (5–10 ml kg−1) of saline or lactated Ringer’s solution ensures adequate right ventricular filling. Should these measures fail, intravenous beta-blockade with propranolol or esmolol slows the heart rate and increases systemic vascular resistance, while decreasing catecholamine stimulation and contractility.
•  Systemic afterload can be increased with alpha agonists in an effort to force more blood flow through the right ventricular outflow tract. Phenylephrine (Neo- Synephrine) 0.02 mg kg−1 i.v. or 0.1 mg kg−1 i.m. is often more rapid and successful than other therapies [39]. Finally, should all measures fail, general anesthesia can reverse the episode or prepare the patient for an emergency aortopulmonary shunt if hypoxemia persists.
•  In patients with chronic hypoxemia, oral therapy with propranolol (0.5–1 mg kg−1 b.i.d.–q.i.d.) can improve oxygen saturations and reduce the risk of hypercyanotic spells. These patients are also at risk for thromboembolic complications, a risk that is highest in patients with coexisting iron deficiency anemia.
• Close monitoring of both hemoglobin concentration and hematocrit is necessary so mean corpuscular volume can be calculated. The hemoglobin should be approximately one-third of the hematocrit; if less, the patient has iron deficiency anemia. These patients should have an elevated hemoglobin at baseline, and a normal hemoglobin value may actually represent a relative anemia. Iron deficiency anemia should be treated with supplemental iron.Whether an infant or young child undergoes initial palliation or complete repair depends on the institution.
•  In the past, the approach was to delay complete repair until later childhood. In the mid-1990s, successful complete repair in early infancy and even the immediate neonatal periodwas demonstrated, and most large units now reserve palliation (either surgical or by interventional catheterization [40–42]) for very small and/or premature infants, or those with additional abnormalities [43–45]. Elective primary repair is usually performed at 6–18 months of age
• what is the management of cyanotic spell?

• An intravenous bolus o f colloid or crystalloid fluid will increase intravascular volume, maximize preload, and improve cardiac output (thereby increasing mixed venous 02 content) and may help prevent hypotension caused by other therapeutic interventions below.

  • Intravenous (or intramuscular) morphine ( 0 . 1 to 0.2 mg/kg) should be given to relieve pain and anxiety, thereby reversing

  endogenous catecholamine release, reducing heart rate, and lowering respiratory rate.

  • Intravenous propranolol ( 0 . 0 1 5 to 0.02 mg/kg) or the shorter-acting esmolol (0.5 mg/kg given over 1 minute, thereafter continued as an infusion) . Beta-receptor antagonists lower heart rate and improve diastolic ventricular filling thus increasing preload and probably also act acutely to increase systemic vascular resistance.

  • Intravenous sodium bicarbonate ( 1 mEq/kg) may be required if there is evidence of worsening acidosis despite the measures above.

  • In unremitting cases, intravenous systemic vasoconstrictors, for example, phenylephrine (boluses of 0.005 to 0.001 mg/kg) , or norepinephrine (0.05 to 1 . 0 .ug!kg/min) may be required.

  • Anesthesia, intubation, and ventilation may ultimately be required to reduce the work of breathing and reduce oxygen consumption and improve mixed venous oxygen content.

  • Very occasionally, severe life-threatening spells may require emergent surgical intervention or mechanical circulatory

  support. Most spells are self-limiting and do not require intensive medical therapy. Many groups consider their onset as an indication for surgical correction, but interval prophylaxis with beta-receptor antagonists (oral propranolol in a dose of 0.25 to 1 mg/kg,2 to 3 times per day) may be helpful if surgery is delayed ( 146).

• what is the role of cath?
• cardiac catheterization is now reserved for those with complex additional abnormalities, such as MAPCAs. The catheterization is most commonly performed from a femoral approach where both arterial and venous access is obtained.
• what are the Postoperative problems and long-term outlook?
• Postoperative problems include both hemodynamic abnormalities and arrhythmias, which are listedResidual VSD is uncommon with current surgical techniques. Echocardiography is fairly useful to detect left-to-right ventricular shunting but, in the presence of a surgical patch, estimating the size of the defect and the degree of shunting may be difficult.
• Residual right ventricular outflow tract obstruction, valvar stenosis, annular stenosis, and supravalvar main pulmonary arterial obstruction can occur, particularly when transannular patching is avoided. The site and severity of obstruction can usually be determined echocardiographically, and balloon valvoplasty may be useful when there is valvar obstruction. If there is a moderate or severe residual supravalvar, annular, or infundibular stenosis, reoperation is usually required.
• Pulmonary artery branch stenosis is relatively common postoperatively and usually occurs in the left pulmonary artery at the site of prior ductal insertion, or at the site of a previous shunt. Fortunately, these conditions can now be treated with a high degree of success by using transcatheter balloon arterioplasty with or without the use of stents
• Tricuspid regurgitation is relatively rare early after the repair, but increases with progressive right ventricular dilation and dysfunction. When operation is required for pulmonary valve replacement or correction of residualoutflow obstruction, tricuspid valve annuloplasty can be a useful adjunctive procedure.
• What are the Postoperative problems.?

             Residual hemodynamic problems

Ventricular septal defect

Right ventricular outflow tract obstruction

Pulmonary valvar and/or annular stenosis

Supravalvar pulmonary artery stenosis

Pulmonary artery branch stenosis

Pulmonary regurgitation

Tricuspid regurgitation

Right ventricular dysfunction

Right ventricular outflow tract aneurysm

Left ventricular dysfunction

Pulmonary hypertension

       Arrhythmia and conduction disturbances

Supraventricular tachycardia

Ventricular tachycardia

Complete heart block

• What is the role of Transcatheter pulmonary valve replacement?
• . A dilated outflow tract makes transcatheter valve replacement infeasible for most patients, at least for the time being. Nonetheless, the introduction of the technique has been one of the most significant advances in the recent history of cardiology, spawning an explosion of methods for treating acquired and congenital valve diseases.
• For those with tetralogy of Fallot, this therapy is essentially restricted to those patients with a conduit between the right ventricle and pulmonary artery. Even so, the results have been very encouraging. Relief of stenosis and abolition of regurgitation can be expected in most, and these results seem to be sustained in the majority during the first 5 years after implantation. The technique has evolved during the decade since its original description byBonhoeffer and colleagues [85], so the longer term outcomes of contemporary series remain to be seen. Furthermore, development of techniques to overcome the anatomic limitations in most of those without a conduit will likely change the face of, and indications for, pulmonary valve replacement in these patients (see also Chapters 10 and 33). Most postoperative patients lead normal or near-normal lives. Patients who have excellent results with normal to near-normal heart size, and no residual significant hemodynamic lesions, can engage in high-level recreational and sports activities [86].
• What is the long term survival of tof patients?
• Long-term outcome after repair of tetralogy of Fallot has been reported to be very good for most patients, with actuarial survival reported as 86% after 32 years compared with an expected rate of 96% [87], 85% after 36 years [88], 84% after 20 years [89], and 84% after 15 years [90].These survival rates are for some of the earliest patients receiving repair, and survival after successful early repair  with  more  current techniques would be predicted to be even better