tetralogy of fallot in adults and its management

1. TETRALOGY
OF FALLOT
IN ADULTS
MODES OF PRESENTATION,
CLINICAL FEATURES,
MANAGEMENT STRATEGIES.

2. DEFINITION
 Congenital heart disease in the adult is presence
of unrepaired or repaired congenital heart disease
in patients aged 21 years or older.

3. PREVALENCE
 Survival of patients with congenital heart disease (CHD) has steadily
improved over the past 4 decades since reparative surgery has become
commonplace. Since the 1970s, more than 80% of patients have survived
into adult life.

4. SURVIVAL VERSUS CURE
 Survival does not necessarily mean cure.
 Cure is best defined as a state that results when survival and quality of life
are indistinguishable from normal.
 Many patients surviving surgery or intervention for CHD are not cured, and
these patients’ residual or recurrent lesions frequently will require repeat
surgery or intervention later in life.
 Even patients who are hemodynamically cured with no residual lesions
may have reduced quality of life compared with the population without
CHD.

5. CATEGORIES OF ADULT CONGENITAL
HEART DISEASE
 Primary Congenital Heart Disease:
 Primary CHD in the adult refers to previously untreated anomalies. These
anomalies tend to cause relatively benign pathophysiologic perturbations,
allowing survival into adulthood without treatment.
 Primary CHD is less common than secondary CHD.

6.  Newly Diagnosed Anomalies
 These fall into two categories.
 The first consists of patients with anomalies that not only allow survival to
adulthood, but are sufficiently benign to escape detection even in
environments with well-organized healthcare systems.
 Typical anomalies include those causing left-to-right shunt (atrial septal
defect [ASD], partial atrioventricular septal defect [AVSD], restrictive
ventricular septal defect [VSD], and restrictive patent ductus arteriosus
[PDA]) and those causing minor valvar obstruction or regurgitation
(bicuspid aortic valve).

7.  The second consists of patients with anomalies that allow survival to
adulthood, but are sufficiently malignant to cause serious
pathophysiologic changes; typically, these patients spend their childhood
in environments without the capability of diagnosing or treating the
anomaly, and only as adults enter an environment capable of detecting it.
 Typical anomalies include all of those listed in the first category, but they
are attended by more serious pathophysiologic perturbations (larger, less
restrictive VSDs), as well as selected cases of many forms of cyanotic
congenital heart disease (tetralogy of Fallot, pulmonary stenosis, and even
some forms of single ventricle).

8.  Previously Diagnosed Anomalies with Benign Pathophysiology
 Typical anomalies include those resulting in small or restrictive left-to-right
shunts and minor valvar lesions. They are detected in infancy or childhood,
but because of lack of important symptoms and pathophysiologic
changes, are left untreated.

9.  Previously Diagnosed Anomalies Thought to Be Inoperable
 Occasionally, adult patients are encountered who were diagnosed with
complex congenital heart disease in infancy; however, because their
pathophysiology was not life threatening and their structural heart disease
was so complex as to be thought inoperable, they have been managed
without surgical correction into adulthood.
 An example is the occasional patient with pulmonary atresia, VSD, or
aortopulmonary collaterals, with mild cyanosis. This patient may be a
candidate for unifocalization and intracardiac repair as an adult.

10.  Secondary Congenital Heart Disease.
 Secondary congenital heart disease refers to patients with previously
treated CHD, which is more common in the adult than primary CHD.

14. TETRALOGY OF FALLOT
 Tetralogy of Fallot is common in adults presenting with congenital heart
disease. Almost exclusively, adult patients have secondary disease, having
undergone repair in infancy or childhood. Rarely, the adult with tetralogy
will present with primary disease.

15. NATURAL HISTORY
 In Tetralogy most patients survive to adulthood after repair.
 Thirty-year survival after repair is 80% to 85%. Surgical cure is rare,
however.
 When an adult presents with unrepaired tetralogy, the physiology is
usually that of mild or mild to moderate RVOT obstruction.
 The majority of adult patients with repaired tetralogy of Fallot present after
the second or third decade of life.
 Males and females appear to be equally affected with symptoms as they
age.

16. PATHOPHYSIOLOGY IN THE ADULT
WITH TETRALOGY OF FALLOT
 The RV dilatation from the pulmonary valve insufficiency is associated with
fibrosis and severe myocardial damage, which then often lead to a
decrease in exercise endurance, and the majority of patients soon develop
ventricular arrhythmias.
 Initially most patients with chronic RV function are asymptomatic, but as
the compensatory mechanisms fail and the ejection fraction decreases,
symptoms start to appear.
 If the condition is not treated at this stage, the RV dysfunction is
irreversible. The arrhythmias occur as a result of progressive dilatation and
stretching of the right atrium and RV.

17.  Atrial arrhythmias of clinical significance are chiefly of the reentry type, but
they may also include atrial tachycardia and atrial fibrillation. These atrial
arrhythmias occur in 10-35% of patients with repaired tetralogy of Fallot.
 Ventricular arrhythmias and sudden death are also known to occur in
those with repaired tetralogy of Fallot.
 Overall, the risk of late sudden death is many times greater in patients who
survive tetralogy of Fallot surgery than in their age-matched counterparts.

18. MORPHOLOGY
 Most often, previously repaired patients present as adults with residual right ventricular
(RV) outflow tract (RVOT) disease, either pulmonary stenosis, regurgitation, or both.
 This may develop in the native RVOT, in a prosthetic valve placed in the native RVOT, or
in a RV-to–pulmonary trunk conduit.
 Initial repair involves a transannular patch in more than 50% of patients, causing
obligatory important pulmonary regurgitation. Surgical pulmonary valvotomy is
performed in many of the remaining patients, leaving them vulnerable to both
regurgitation and stenosis.
 Other less common reasons for adult presentation include residual ventricular septal
defect (VSD), residual atrial septal defect, tricuspid regurgitation, aortic regurgitation,
dilated aortic root, branch or peripheral pulmonary artery stenosis, stroke, and various
arrhythmias.

19. CLINICAL FEATURES AND DIAGNOSTIC
CRITERIA
 Presentation:
 The typical adult with previously repaired tetralogy of Fallot presents with
signs and symptoms related to pulmonary regurgitation, including exercise
intolerance and palpitations.
 If intervention is not undertaken at that time, RV dilatation progresses and
right heart failure or atrial or ventricular tachycardia may be the mode of
presentation.
 15% of adult tetralogy patients have a dilated ascending aorta (associated
with a history of long shunt-to-repair interval and with pulmonary atresia),
but rarely leads to presentation.

20. ADULTS WITHOUT PRIOR SURGERY
 In the current era, it is unusual to encounter patients who have not had
palliative or corrective surgery for Tof.
 Many adults with untreated tetralogy may have experienced one or more
of the complications associated with cyanosis such as cerebrovascular
accident, bacterial endocarditis, paradoxical embolism and brain abscess.
 Long-term survival without surgery often implies mild pulmonary stenosis
during childhood or the development of large-size collateral vessel to
augment pulmonary blood flow.

21. ADULTS WITH PRIOR CORRECTION OF
TETRALOGY OF FALLOT
 Common complications in adult survivors are:
1. Significant PR : Severe chronic PR eventually leads to symptomatic RV
dilation and dysfunction.
2. Residual RVOTO can occur at any level, from infundibulum to the level of
branch PA.
3. Tricuspid regurgitation due to RV dilation leads to right atrial
enlargement and subsequent development of troublesome atrial
tachyarrhythmias.
4. Residual VSD due to patch dehiscence or failure of complete closure at
the time of surgery leads to progressive LV volume overload.

22. 1. Progressive aortic root dilation is related to both intrinsic abnormalities
of aorta (cystic medial necrosis) and increased flow. It may lead to AR
and, very rarely, to true aneurysm formation and aortic dissection or
rupture.
2. LV dysfunction appearing during follow-up is a risk factor for SCD in ToF
patients. It happens due to inadequate myocardial protection (during
operations in the old era), LV volume overload from palliative shunts, and
residual VSD and/or AR.
3. Tachyarrhythmias.

23. SIGNS AND SYMPTOMS OF
TETRALOGY OF FALLOT
 The clinical features of tetralogy of Fallot in the adult are directly related to
the severity of the anatomic defects and may include the following:
 Lack of exercise endurance
 Palpitations
 Gradual decline in bodily functions

24.  Physical findings in adults include the following:
 Cyanosis
 Exertional dyspnoea
 Syncope
 Palpitations
 Evidence of right-sided heart failure (elevated jugular venous pressure
[JVP], ascites, peripheral oedema, hepatomegaly) Large "A wave" in JVP
tracings.
 Arrhythmias

25. SYSTEMIC EFFECTS OF CYANOSIS
Failure to thrive Cyanotic spell Brain abscess
Haematological-
polycythaemia, haemostatic
problems, iron deficiency
anaemia.
Vascular-thrombosis, stroke.
Renal problems
Rheumatological- clubbing,
hypertrophic
osteoarthropathy.
Bacterial endocarditis
Pulmonary-PAH,
haemoptysis.
Gall stones
Ventricular dysfunction Dental abnormalities

26. Failure to thrive
 Growth failure and poor weight gain are very common.
 Major causes are decreased calorie intake, malabsorption, increased
metabolic demand, GE reflux, immaturity of GI tract, genetic factors.
 Developmental milestones are also delayed.
 In early postnatal life heart switches from carbohydrate metabolism to beta
oxidation of fatty acids mechanism for energy, and during hypoxia it
switches back to glycolytic metabolism leading to reduced energy levels.
 Unmetabolized fatty acids exert inhibitory effects on glycolytic cycle
leading to reduced cardiac contractility.

27. Cyanotic spells
 Dependant on systemic vascular resistance and severity of pulmonary
stenosis.
 Increased contractility of infundibulum enhances RVOTO and causes right
to left shunt.
 This results in fall of arterial po2,rise in pco2 and acidosis, which stimulates
respiratory centre leading to hyperpnea.
 Hyperpnea increases venous return and increases right to left shunt,
further aggravating cyanosis. leading to a vicious cycle of hyperventilation
and hypoxia/cyanosis.

28. Brain abscess
Common in paediatric age, usually after 3y of age.
Staph.aureus, streptococcus group and anaerobes are typical causative agents.
Common sites are parietal, frontal and temporal lobes.
clinically present with vomiting, fever, headache, seizures, papilledema and coma.
Hypoxia and hyper viscosity are two main factors.
Right to left shunting allows passage of bacteria colonizing airway to cerebral circulation.
Hyper viscosity and microcytic hypochromic anaemia causes focal cerebritis followed by abscess.

29. Polycythaemia
 Erythropoietin production is increased in response to hypoxemia, which
leads to hyper viscosity.
 Symptoms such as headaches, dizziness, faintness, fatigue, altered
sensorium, paraesthesia, tinnitus, myalgias usually occur only when
haematocrit level is >65%.
 Phlebotomy provides symptomatic relief, but can lead to iron deficiency
anaemia, and is indicated only in patients with Hb>20mg/dl and
haematocrit >65%.

30. Haemostatic problems
 They are attributed to polycythaemia, shortened platelet survival, alteration
of clotting factors.
 Elevated PT,APTT, decreased levels of factors V,VII,VIII and XI.
 Thrombocytopenia may be due to reduced megakaryocytes fragmentation
into platelets.
 This erythrocytosis can lead to bleeding diathesis, which can be mild to
moderate and severe life threatening haemoptysis or postop bleeding.

31. Iron deficiency anaemia
 Can occur due to excessive bleeding or phlebotomy.
 Typical indices of iron deficiency, hypochromia, microcyosis may not occur,
hence complete iron metabolism work up, including serum ferritin and
transferrin levels are required.

32. Vascular complications
thrombosis
 In cyanosis, hypoxemia through activation of neutrophils, which release
vasoactive and chemotactic substances, causes endothelial injury(alters the
Virchow’s triad) and subsequent activation of platelets and coagulation.
 There is also altered composition of coagulation factors, increased FVIII
levels, decreased protein C, antithrombin III.
 Polycythaemia and hyper viscosity leads to vascular stasis.
 Due to intracardiac mixing of blood, thrombi can migrate to lungs leading
to pulmonary embolism and also to brain leading to stroke.

33. Stroke
 Embolic material which originates in venous system reaches systemic
circulation after bypassing the pulmonary capillary filter and is known as
paradoxical embolism.
 These paradoxical embolism leads to stroke.
 In patients with erythrocytosis, TIA can be due to problems of hyper
viscosity or altered RBCs.

34. Renal problems
 Also termed cyanotic nephropathy.
 Effects both glomerular and tubular function, which results in proteinuria and
azotaemia, which can lead to AKI and CKD.
 There is direct relation between duration of cyanosis and rising trend toward
CKD and end stage renal disease.
 Cardiorenal syndrome- chronic cardiac conditions lead to progressive kidney
disease and podocyte injury.
 Hyper viscosity, chronic hypoxia, changes in intraglomerular hemodynamic,
altered autonomic regulation, neurohumoral activation are the major factors.
 Proteinuria, hyperuricemia, renal failure are common presentations.
 Other problems such as gout and uric acid nephropathy are rare presentations.

35. Rheumatological complications
clubbing
 Described as focal bulbous enlargement of terminal segments of fingers or
toes.
 Occurs because of proliferation of connective tissue between distal
phalanx and nail matrix, which results in increase in both AP and lateral
diameter of nails.
 May be due to lodging of megakaryocytes or platelet clusters in peripheral
vasculature of digits, as they bypass the pulmonary capillary vasculature in
cases of right to left shunt.
 PDGF and VEGF lead to increased vascularity, permeability and connective
tissue changes.

36. Hypertrophic osteoarthropathy
 It is a syndrome which constitutes digital clubbing, periostitis with new
subperiosteal bone formation and arthritis.
 Usually involves long bones of lower limbs.
 VEGF and PDGF are important factors for vascular, bone stimulating
effects, osteoblast formation and migration.

37. Bacterial endocarditis
 In persons with CHD, there are structural heart changes(native or post op)
that causes turbulence and sheer force in blood flow and disrupt the
endothelium, leaving heart vulnerable by exposing the sub endocardial
collagen and extracellular matrix.
 During healing, deposition of fibrin and platelet adherence leads to scar
formation and pathogenic organisms may settle and infect the
endocardium.
 Suture lines, prosthetic material, are at particular risk.

38. Pulmonary complications
PAH
 4-15% cases develop PAH.
 Depends on location and size of shunt.
 Inhomogeneous pulmonary perfusion, where areas of hyperperfused lung
may develop pulmonary vascular disease(PVD).
 These PVD involve one part of the lung rather than entire lung leading to
segmental pulmonary hypertension.

39. Haemoptysis
 Aetiologies include haemorrhage from enlarged tortuous bronchial
arteries(MAPCAs),thrombotic lesions in small pulmonary arteries, pseudo
fibrosis at lung apices.
 Associated tuberculosis, should be looked for.

40. Gallbladder stones
 Increased red cell counts in cyanosis increases bilirubin, which leads to
pigment gall stones.
 Management is same as in general population, depends on symptomatic
status.

41. Ventricular dysfunction
 Important risk factor for morbidity and mortality.
 Can be due to aberrant left coronary artery from pulmonary artery, CoA,
myocarditis, cardiomyopathy, arrythmias, shunt overflow.
 Studies showed ventricular dysfunction due to chronic hypoxia by subcellular
effects and only few of them showed improvement with oxygenation.
 Acute hypoxia due to severe cyanotic spells reverses rapidly after early
management of spell.
 Hence hypoxia due to cyanotic CHD is a strong reversible risk factor for
ventricular dysfunction.
 Total correction of cyanosis leads to correction of hypoxia which leads to
improvement in myocardial function.

42. Dental abnormalities
 Dental caries have high incidence and are due to enamel abnormalities of
primary dentition as chronic hypoxia can cause abnormality in enamel
formation and mineralization.
 Preventive dental care and proper oral hygiene are important to manage
these abnormalities.

43.  Long-standing abnormal right-sided hemodynamics, particularly in patients with
tetralogy of Fallot, single-ventricle morphology with Fontan surgery, and Ebstein
anomaly, may result in chronic hepatic venous hypertension and hepatic congestion,
leading to hepatic dysfunction and cirrhosis, gastroesophageal varices, and even
hepatocellular carcinoma.
 Scoliosis is common in patients with chronic cyanosis. This may lead to deformity of the
thorax, causing ventilatory compromise. Pulmonary function tests are required in all
adult patients with CHD and scoliosis who are under consideration for cardiac surgery.

44.  Clinical findings in operated patients mostly include a widely split second
heart sound, and may include a low-pitched early-ending diastolic murmur
of PR, long loud ejection systolic murmur of RVOTO, a high-pitched
diastolic murmur of AR, as well as the pansystolic murmur of a residual
VSD.
 ECG shows complete right bundle branch block with wide QRS. A
progressively widening QRS >180 ms is risk factor for VT and SCD

45. DIAGNOSTIC CONSIDERATIONS
 When an adult with tetralogy of Fallot (TOF) presents, a wide variation
exists in their clinical signs and symptoms, primarily owing to differences in
the basic anatomic morphology of the heart and the types of surgical
repair performed in infancy.
 For those who already underwent surgery in childhood, the most common
reason for later presentation is pulmonary valve regurgitation.

46.  Other disorders that also should be considered when evaluating an adult
patient with tetralogy of Fallot include the following:
1. Endocarditis
2. Cerebral embolism
3. Cardiogenic shock
4. Pulmonary atresia
5. VSD
6. Lung disorders (e.g., asthma, reactive airway disease)
7. Right heart failure

47.  The diagnosis is already known in the great majority of adults with tetralogy of Fallot.
Further diagnostic workup is aimed at identifying residual defects. The following
laboratory studies may be helpful:
 Complete blood cell count: A mild anemia may be present; polycythemia is rare in the
absence of cyanosis.
 Coagulation profile: May be abnormal in patients with cyanosis and bleeding
 Arterial blood gas (including serum lactate, base excess, oxygen partial pressure [PO2]):
The patient's oxygenation status, serum lactate levels, and base excess value appear to
be prognostic markers for mortality in those undergoing surgical repair of tetralogy of
Fallot.
 Blood cultures: Obtain blood cultures in febrile patients to rule out endocarditis or
sepsis.

48. MANAGEMENT OF HIGH
PCV(PLASMAPHERESIS)
 Plasmapheresis is a term used to refer to a broad range of procedures in
which extracorporeal separation of blood components results in a filtered
plasma product.
 The filtering of plasma from whole blood can be accomplished via
centrifugation or the use of semipermeable membranes.
 Centrifugation takes advantage of the different specific gravities inherent
to various blood products, such as red blood cells (RBCs), white blood cells
(WBCs), platelets, and plasma.
 Membrane plasma separation uses differences in particle size to filter
plasma from the cellular components of blood.

49.  Erythrocytapheresis (selective removal of RBCs) is used in conditions such
as sickle cell disease or malarial infection, in which RBCs are selectively
removed and replaced with donor erythrocytes.
 Platelet apheresis (selective removal of platelets) can be used in conditions
of thrombocytosis (e.g., polycythemia vera).

50.  The electrocardiogram (ECG) is critical to evaluation, identifying the
predominant rhythm (sinus, junctional, or atrial fibrillation or flutter),
presence of ventricular ectopy, and QRS complex duration. Holter
monitoring and formal electrophysiologic evaluation should be undertaken
to fully characterize any rhythm disturbance.
 Arrhythmias and risk assessment for SCD may need Holter monitoring
with event recorder and formal EP testing.

51.  Imaging studies include the following:
 Chest radiographs
 Echocardiography
 Magnetic resonance imaging (MRI)

52.  Chest radiographs have the following attributes:
 May be normal or depict cardiomegaly and prominent RV shadowing
 Although the classic boot-shaped heart (Coeur en sabot) is the hallmark
of the disorder in infants, this shape of the heart may not be seen in adult
patients.

53.  Echocardiography has the following attributes:
 Color-flow Doppler echocardiography: Assesses overall cardiac function,
and for the presence of any residual VSD, ductus arterosus, or atrial septal
defect
 Allows evaluation of the valvular anatomy but is unable to visualize the
coronary anatomy in adults
 Reveals the grade and severity of any RVOT obstruction
 Estimates severity of pulmonary regurgitation, RV function and size,
tricuspid regurgitation, as well as left-sided valvar and ventricular function.

54.  MRI has the following attributes:
 Gold standard for assessing RV function and size, and for quantifying the
pulmonary regurgitant volume.
 Maps the velocity of pulmonary regurgitation and provides good
delineation of the aorta size, the status of the RVOT, and the presence of
VSDs, and/or RV hypertrophy.
 Can also be used to measure intracardiac pressures, gradients, and blood
flows.
 MRI is quite sensitive at detecting branch pulmonary artery stenosis, which
may be contributing to the increasing pulmonary valve insufficiency and
the formation of aortopulmonary collaterals.

55.  Late enhancement with gadolinium demonstrates extent of fibrosis in the
ventricles and has been correlated with the risk of VT and SCD.
 CT is an alternative to CMR and is especially useful for delineating the
extent of conduit calcification, information required for deciding site for
percutaneous valve anchorage and for patients with pacemakers and
defibrillators in place.

56.  Cardiac catheterization allows the following:
 Assessment of the pulmonary annulus size and pulmonary arteries
 Assessment of the severity of RVOTO
 Location of the position and size of the VSD
 Ruling out possible coronary artery anomalies (Specifically, the left
anterior descending coronary artery arises from the right sinus of Valsalva
and crosses the RVOT in about 10% of tetralogy patients and thus is
vulnerable to injury during RVOT intervention).

57. RISK FACTORS FOR SURGERY IN
ADULTS WITH TETRALOGY OF FALLOT
 Cardiogenic shock
 Poor RV function
 Diminutive pulmonary arteries
 Other major associated anomalies, such as tricuspid atresia or an anomalous
coronary artery
 Multiple previous surgeries
 Advanced age
 Severe annular hypoplasia
 High peak RV–to–left ventricular pressure ratio
 Multiple ventricular septal defects (VSDs)
 Right-sided heart failure

58. TIMING OF SURGERY IN ADULTS WITH
TETRALOGY OF FALLOT
 Previously, surgery was usually recommended based on the presence of
whether the QRS interval was longer than 180 milliseconds on
electrocardiography (ECG).
 More recently, some surgeons believe that pulmonary valve replacement
is only necessary when there is evidence of RV dysfunction.
 Others state that it should be performed when the patient is symptomatic.
 Still others opine that earlier surgery based on echocardiographic findings
irrespective of symptoms is appropriate.

59.  The consensus is that waiting for symptoms to develop before
undertaking surgery may be too late and the RV may then become
irreversibly damaged.
 Regardless of the existing debate, the pulmonary valve should be replaced
before heart failure develops.

60. MANAGEMENT
 The surgical procedures used in adults with tetralogy of Fallot will be for residual or
recurrent disease in most cases.
 The first surgery to repair tetralogy of Fallot consisted of placement of a shunt to relieve
the cyanosis.
 Primary repair is currently recommended within the first 12 months of life; in general,
excellent results are obtained at most centers.
 Ever since primary repair became the standard of care nearly 30 years ago, more adult
patients with repaired tetralogy of Fallot in early childhood are living longer and they are
being seen at clinics.
 Some patients who never underwent surgery for mild tetralogy during childhood may
present as adults with a variety of symptoms, and other patients who may only have had
a palliative procedure (e.g., shunt placement) can also present as adults.

61.  Corrective surgery for tetralogy of Fallot performed in childhood is not
curative surgery. Rather, this procedure only corrects the anatomic defects—
without changing the progression of the disease or addressing the
consequences of using a patch.
 Thus most surgeons consider the initial surgery for tetralogy of Fallot to be
long-term palliation, not definitive surgery.
 With advancing age, children who had corrective surgery are usually
asymptomatic for the first decade after the initial procedure.
 Thereafter, they develop varying degrees of pulmonary valve insufficiency,
which, in turn, can lead to RV overload and RV distention and failure.
 RV enlargement also leads to the development of atrial and ventricular
arrhythmias, which, if not recognized early, are a common cause of high
morbidity and mortality.

62. RETROGRADE AUTOLOGUS PRIMING
 Cardiac surgery is associated with a high incidence of homologous blood
transfusion. Concern about the side effects (immunologic reactions, viral
transmission) of homologous blood transfusion have led to the development
of many methods to conserve blood in cardiac surgery.
 Preoperative autologous blood donation (PABD)
 Acute normovolemic hemodilution (ANH)
 Cell salvage
 Pharmacologic agents
 Displacing some of the circuit prime at the initiation of CPB with the patient’s
own circulating blood in both an antegrade direction through the venous
cannula and a retrograde direction through the arterial cannula has become
known as retrograde autologous priming (RAP)

63.  Hemodilution occurring with cardiopulmonary bypass imposes a risk for
blood transfusion. Autologous priming of the cardiopulmonary bypass
circuit at the initiation of bypass partially replaces the priming solution
with autologous blood.
 RAP of the CPB circuit reduces the priming volume of the CPB circuit and
hence limits hemodilution at this time. This reduced hemodilution allows a
higher HCT value to be maintained throughout CPB, which may be
beneficial.
 After CPB the higher HCT may mean that the patient is less likely to reach a
transfusion threshold and receive a homologous blood transfusion.

66. SURGERY FOR ADULTS WITH
TETRALOGY OF FALLOT
 Surgery is usually performed under cardiopulmonary bypass(retrograde
autologous priming) using cardioplegia. The heart is arrested, the VSD is
closed with a patch, the infundibulum is widened, and the pulmonary valve
is repaired.
 Unlike in infants, transannular patching is rarely performed in adult
patients because this procedure often leads to pulmonary insufficiency
later in life. Currently, most surgeons replace or repair the pulmonary valve
in adults rather than performing a transannular patch.
 Pulmonary valve replacement, helps decrease the RV size as well as
improve RV function over the long term. In general, however, the incidence
of arrhythmias remains unchanged.

67.  In adults with previously repaired tetralogy who have pulmonary regurgitation,
porcine, xenograft, bovine pericardial, and allograft valved conduits may be
placed into the RVOT.
 Catheter-based placement of a pulmonary valve is possible as a “valve-in-
valve” procedure requiring a previously placed bioprosthetic conduit 18 to 20
mm in diameter
 Peripheral or segmental pulmonary artery stenoses may be addressed by
balloon dilatation, either proceeding the procedure or as a hybrid procedure.
 Catheter-based methods may be applicable for residual atrial or ventricular
septal defects, branch pulmonary artery stenoses, aortopulmonary collateral
arteries, and closure of previously placed surgical shunts.

68. MECHANICAL VERSUS BIOPROSTHETIC
REPLACEMENT VALVES
 Because the right side of the heart and pulmonary artery vessels are a low-
flow system, insertion of a mechanical prosthetic valve is associated with a very
high risk of thrombosis. Patients will require lifelong anticoagulation, which
also exposes them to a risk of bleeding.
 Bioprosthetic valves, human tissue (homografts) or animal tissue (bovine
pericardium or porcine heart valve)can be implanted as solo valves or as part
of a conduit in the RVOT.
 Bioprosthetic valves eliminate the need for lifelong anticoagulation, they are
not durable in young patients.
 Nearly 40-55% of bioprosthetic valves fail within the first decade after
implantation, guaranteeing that an otherwise healthy 30-40-year-old patient
will need to undergo one or more open heart procedure(s) in the future, which
also increases the risk of complications.

69. TREATMENT FOR ARRYTHMIAS
 Some patients continue to have ventricular arrhythmias despite surgical
repair; they are at greater risk for sudden death. These patients may
benefit from placement of an automatic implantable cardioverter
defibrillator (AICD).
 Radiofrequency ablation (RFA) has become another option to treat
arrhythmias in adult patients with tetralogy of Fallot. This technique may
help to resolve atrial or ventricular arrhythmias.

70. REVISION/REOPERATION
 Indications for early reoperation include a residual ventricular septal
defect (VSD) or a residual RV outflow tract obstruction (RVOTO).
 Residual VSDs are poorly tolerated in patients with tetralogy of Fallot
because these individuals cannot tolerate an acutely imposed volume
overload.
 A residual VSD with a 2:1 shunt or an RVOTO of greater than 60 mm Hg is
an urgent indication for reoperation.

71. RESULTS
 Surgical outcomes after operations on the RVOT in adults with previously
repaired tetralogy are excellent, with early mortality of 0% to 2%.
 Late survival is also excellent, with mortality of 0.5% per patient-year.
 Sudden death from arrhythmias is the main mode of premature death.
Ventricular tachycardia is the most common cause.
 Preserving RV function is the best way to minimize late fatal arrhythmias.
This is best achieved by early primary repair with attention to myocardial
preservation and aggressive intervention in adults with residual or
recurrent hemodynamic abnormalities that threaten to compromise RV
function.

72.  After pulmonary valve replacement, some studies have shown a 5-year
survival in excess of 90% and 86% at 10 years.
 Pulmonary valve replacement slows down or reverses the progression of
some complications associated with pulmonary valve insufficiency,
including RV dysfunction and tricuspid regurgitation.

73.  Comparing porcine (Medtronic Mosaic valve), bovine pericardial
(Carpentier-Edwards), and pulmonary allograft valved conduit (Cryolife)
prostheses, revealed that allograft valved conduits initially had the lowest
gradients; however, they also developed regurgitation and required
reintervention sooner.
 Studies indicate that primary repair can be performed in the adult with
varying, but generally low, early mortality risk, and with substantial
improvement in functional status and quality of life. Late survival, however,
is substantially lower than in the general population, and lower than for
tetralogy patients who undergo operation earlier in life.

74. PROGNOSIS
 In the present era of cardiac surgery, children with simple forms of
tetralogy of Fallot (TOF) enjoy good long-term survival with an excellent
quality of life.
 About 75% infants who undergo repair during infancy will survive to reach
their second to third decade of life without major consequences. However,
after the first two decades of life, symptoms start to appear due to
pulmonary valve regurgitation. By the fourth decade of life, most survivors
are symptomatic.

75.  Adult patients with tetralogy of Fallot who undergo surgery again are
usually symptom free for 10-15 years, but by the time they reach their fifth
decade, even these patients begin to have symptoms.
 Second surgery reduces the rate of death, most of these individuals have a
shorter lifespan than age-matched control subjects without a history of
congenital heart disease. Adults with recalcitrant arrhythmias and right
heart failure have the worst prognosis.

76. SURGICAL COMPLICATIONS
 Early postoperative complications following repair of tetralogy of Fallot
(TOF) include the creation of heart block and residual ventricular septal
defects (VSDs).
 Ventricular arrhythmias are more common and are reportedly the most
frequent cause of late postoperative death.

77.  Short-term postoperative complications include the following:
1. Rebleeding
2. Tamponade
3. Persistent elevation in right ventricular (RV) pressures
4. Right heart failure
5. Sternal wound infection
6. Atrial arrhythmias

78.  Long-term postoperative complications include the following:
1. Pulmonary valve insufficiency
2. Persistent RV outflow tract obstruction
3. Atrial and ventricular arrhythmias
4. Right heart failure
5. Sudden death
6. Endocarditis
7. Septic central emboli

79. FOLLOWUP
 Important concern regarding patients with tetralogy of Fallot is that many
are lost to follow-up as they become adults, and thus the opportunity to
manage complications before they become irreversible can be missed.
 In other cases, the primary care provider is unaware of the need to follow
these patients, owing to the erroneous belief that surgery is curative.
 It is currently recommended that all children with tetralogy of Fallot be
followed closely, because many will present with symptoms in their third
decade of life. Some pediatric cardiology centers recommend a baseline
magnetic resonance imaging of the heart even in the absence of
symptoms every 3-7years.

80. THE FUTURE

81. CATHETER BASED INTERVENTIONS
 Catheter-based intervention may be applicable in selected cases of RVOT
obstruction or regurgitation, residual atrial and ventricular septal defect,
and branch and peripheral pulmonary artery stenosis.
 Preferred for closing acquired aortopulmonary collaterals and often for
closing previously placed surgical shunts.
 May be considered for RVOT obstruction if the obstruction is at the valve
level or beyond, but not if it is in the infundibulum.
 Catheter-based placement of a pulmonary valve in combination with
balloon dilatation and stenting of obstruction is a more rational approach.

82.  If surgical reconstruction of the RVOT is indicated, then balloon dilatation
or stenting of central branch pulmonary artery stenosis should not be
performed. Rather, the branch pulmonary artery obstruction should be
repaired surgically as part of the RVOT procedure.
 If no immediate surgical procedure is anticipated for a patient, balloon
dilatation of isolated central branch pulmonary artery stenosis is a
reasonable approach, but stenting should be avoided.

83. PERCUTANEOUS VALVE
REPLACEMENT
 With innovations in endovascular technology, the Melody transcatheter
pulmonary valve can be implanted percutaneously via the femoral vein,
guided by fluoroscopy.
 After valve implantation, there is a moderate reduction in pulmonary valve
insufficiency and the ventricular size, as well as marked improvement in
exercise tolerance.

84.  Percutaneous placement of a pulmonary valve, however, is only applicable
in about 10% of repaired tetralogy patients with RVOT problems.
 Criteria for this procedure include requirement of a previously placed RV-
to–pulmonary trunk conduit with a diameter of at least 16 mm, or
previously placed bioprosthetic valve with a diameter of 18 to 20 mm.
 Thus, the great majority of repaired tetralogy patients—those with native
RVOTs or transannular patches—are not candidates.

86. 2018 AHA/ACC GUIDELINES
 Management and care of patients with tetralogy of Fallot (repaired or unrepaired) should
involve a cardiology with expertise in CHDs. Interventions involving congenital heart
lesions (cardiac surgery, catheter-based interventional cardiac procedures,
electrophysiologic procedures) in adults with CHD should be performed by those with
expertise in adult CHD procedures as well as that of a cardiologist specializing in adult
CHD.
 The AHA/ACC anatomic/physiologic (AP) classification categorizes repaired tetralogy of
Fallot to be of moderate complexity.
 Experts in imaging with ultrasonography, echocardiography, and cardiac magnetic
resonance imaging (CMRI) are preferred for cardiac imaging in patients with tetralogy of
Fallot.

87.  Use a standard 12-lead electrocardiogram (ECG) in adults with CHD with serial
assessment based on the specific CHD AP classification or when symptoms develop or
worsen. Use ambulatory ECG monitoring in patients with CHD who are at risk for
tachyarrhythmia, bradyarrhythmia or heart block, of when symptoms of a potential
arrhythmic etiology develop.
 Use ECG to measure QRS duration in patients following repair of tetralogy of Fallot and
as part of the evaluation for cardiac resynchronization therapy (CRT).
 CMRI, cardiac computed tomography (CCT) scanning, transesophageal
echocardiography (TEE), and/or cardiac catherization may be superior to transthoracic
echocardiography (TTE) in the assessment of right ventricular (RV) size and function in
repaired tetralogy of Fallot, systemic RVs, and other conditions associated with RV
volume and pressure overload.
 Tetralogy of Fallot among other cardiac findings is commonly associated with DiGeorge
(velocardiofacial syndrome) and Down syndromes.

88. DIAGNOSTIC RECOMMENDATIONS
 CMRI is useful for quantification of ventricular size and function, pulmonary valve
function, pulmonary artery (PA) anatomy, and left heart abnormalities in patients with
repaired tetralogy of Fallot.
 Obtain coronary artery compression testing before performing right ventricle-to-PA
conduit stenting or transcatheter valve placement in repaired tetralogy of Fallot.
 Programmed ventricular stimulation can be useful for risk stratification of adults with
tetralogy of Fallot and additional risk factors for sudden cardiac death (SCD).
 In patients with repaired tetralogy of Fallot, cardiac catheterization with angiography, if
indicated, is reasonable to assess hemodynamics when adequate data cannot be
obtained noninvasively in the setting of an arrhythmia, heart failure, unexplained
ventricular dysfunction, suspected pulmonary hypertension, or cyanosis.

89. THERAPEUTIC RECOMMENDATIONS
 Pulmonary valve replacement (surgical or percutaneous) for symptomatic
relief is recommended for patients with repaired tetralogy of Fallot and
moderate or greater pulmonary regurgitation (PR) with otherwise
unexplained cardiovascular symptoms.
 Pulmonary valve replacement (surgical or percutaneous) is reasonable for
preservation of ventricular size and function in asymptomatic patients with
repaired tetralogy of Fallot and ventricular enlargement or dysfunction and
moderate or greater PR.

90.  Primary prevention with implantable cardioverter-defibrillator (ICD)
therapy is reasonable in adults with tetralogy of Fallot and multiple risk
factors for SCD.
 Surgical pulmonary valve replacement may be reasonable for adults with
repaired tetralogy of Fallot and moderate or greater PR with other lesions
that require surgical interventions.
 Consider pulmonary valve replacement, in addition to arrhythmia
management, for adults with repaired tetralogy of Fallot and moderate or
greater PR and ventricular tachyarrhythmia.

91. RV-TO-PA CONDUIT
 Diagnostic recommendations:
 Coronary artery compression testing with simultaneous coronary
angiography and high-pressure balloon dilation in the conduit is indicated
before RV-to-PA conduit stenting or transcatheter valve placement.
 In patients with stented RV-to-PA conduits and worsening pulmonary
stenosis (PS) or PR, evaluate for conduit complications, including
fluoroscopy to evaluate for stent fracture and blood cultures to assess for
infective endocarditis.
 In adults with RV-to-PA conduit and arrhythmia, congestive heart failure,
unexplained ventricular dysfunction, or cyanosis, cardiac catheterization is
reasonable to assess the hemodynamics.

92.  Therapeutic recommendations:
 RV-to-PA conduit intervention is reasonable for adults with RV-to-PA
conduit and moderate or greater PR or moderate or greater stenosis with
reduced functional capacity or arrhythmia.
 RV-to-PA conduit intervention may be reasonable for asymptomatic adults
with RV-to-PA conduit and severe stenosis or severe regurgitation with
reduced RV ejection fraction or RV dilatation.

96. THANK YOU