Tetralogy of Fallot

Prepared by Group 15

Leader: Christine Grace Ponciano

Members:Agapay, SaraDe Mesa, JerimaeDel Moro, ZandyIlagan, OmarOliveros, CarmelaPuyal, Jennica AiraTuraray, Francesca ElaineUmbrete, Jessica MaeImpreso, Cindy kathleen

General Objective:•To learn information about Tetralogy of Fallot

Specific Objectives:• To know the signs and symptoms of TOF

• To know the pathophysiology of TOF• The anatomy & physiology ofTOF• To know the Emergency Medicines of Tof• Nursing Management• Nursing Diagnosis

Definition of Terms

INITIAL RIGHT-to-LEFT SHUNT (cyanotic)

TETRALOGY OF FALLOT the most common cyanotic CHDClassical Diagnostic Symptoms, 4 components:1. Pulmonary Artery Stenosis: The

principle etiology responsible for the pulmonary hypertension and right-to-left shunt.

2. Ventricular Septal Defect 3. Dextroposition of Aorta

(overriding): Aorta originates from the septal area, such that it receives blood originating from both right and left ventricle.

4. Right Ventricular Hypertrophy

Condition Description

A: Pulmonary stenosis

A narrowing of the right ventricular outflow tract and can occur at the pulmonary valve (valvular stenosis) or just below the pulmonary valve (infundibular stenosis). Infundibular pulmonic stenosis is mostly caused by overgrowth of the heart muscle wall (hypertrophy of the septoparietal trabeculae), however the events leading to the formation of the overriding aorta are also believed to be a cause. The pulmonic stenosis is the major cause of the malformations, with the other associated malformations acting as compensatory mechanisms to the pulmonic stenosis. The degree of stenosis varies between individuals with TOF, and is the primary determinant of symptoms and severity. This malformation is infrequently described as sub-pulmonary stenosis or subpulmonary obstruction.

B: Overriding aorta

An aortic valve with biventricular connection, that is, it is situated above the ventricular septal defect and connected to both the right and the left ventricle. The degree to which the aorta is attached to the right ventricle is referred to as its degree of "override." The aortic root can be displaced toward the front (anteriorly) or directly above the septal defect, but it is always abnormally located to the right of the root of the pulmonary artery. The degree of override is quite variable, with 5-95% of the valve being connected to the right ventricle.

C: ventricular septal defect (VSD)

A hole between the two bottom chambers (ventricles) of the heart. The defect is centered around the most superior aspect of the ventricular septum (the outlet septum), and in the majority of cases is single and large. In some cases thickening of the septum (septal hypertrophy) can narrow the margins of the defect.

D: Right ventricular hypertrophy

The right ventricle is more muscular than normal, causing a characteristic boot-shaped (coeur-en-sabot) appearance as seen by chest X-ray. Due to the misarrangement of the external ventricular septum, the right ventricular wall increases in size to deal with the increased obstruction to the right outflow tract. This feature is now generally agreed to be a secondary anomaly, as the level of hypertrophy generally increases with age

Anatomy &

Physiology of the disease

Patent Ductus Arteriosus: Often co-occurs with Tetralogy, although it isn't part of the syndrome. It is helpful in Tetralogy, as it provides a channel for shunted blood to get back into the pulmonary circulation where it belongs.

(Right Atrium ------> Right Ventricle ------> VSD ------> Left Ventricle ------> Aorta ------> through the Ductus Arteriosus ------> Pulmonary Arteries)

Normal Heart

Heart with Tetralogy of Fallot

Pathophysiology of the Disease

Tetralogy of Fallot results in low oxygenation of blood due to the mixing of oxygenated and deoxygenated blood in the left ventricle via the VSD and preferential flow of the mixed blood from both ventricles through the aorta because of the obstruction to flow through the pulmonary valve. This is known as a right-to-left shunt. The primary symptom is low blood oxygen saturation with or without cyanosis from birth or developing in the first year of life. If the baby is not cyanotic then it is sometimes referred to as a "pink tet". Other symptoms include a heart murmur which may range from almost imperceptible to very loud, difficulty in feeding, failure to gain weight, retarded growth and physical development, dyspnea on exertion, clubbing of the fingers and toes, and polycythemia.Children with tetralogy of Fallot may develop "tet spells". The precise mechanism of these episodes is in doubt, but presumably results from a transient increase in resistance to blood flow to the lungs with increased preferential flow of desaturated blood to the body. Tet spells are characterized by a sudden, marked increase in cyanosis followed by syncope, and may result in hypoxic brain injury and death. Older children will often squat during a tet spell, which cuts off circulation to the legs and therefore improves blood flow to the brain and vital organs.

Assessment

Activity/RestInability to carry on normal activitiesNocturnal/exertion-related dyspnea; orthopnea

CirculationTachycardia, palpitations; severe dysrhythmia.History of congenital/organic heart disease, rheumatic fever.Upward displacement of the diaphragm and heart proportionate to uterine size.May have a continuous diastolic or presystolic murmur; cardiac enlargement; loud systolicmurmur, associated with a thrill.BP may be elevated or may be decreased with decreased vascular resistance.Clubbing of toes and fingers may be present, with symmetric cyanosis in surgically untreatedtetralogy of Fallot.

EliminationUrine output may be decreased.Nocturia.

Food/FluidObesity (risk factor)May have edema of the lower extremitiesPain/DiscomfortMay report chest pain with/without activity

RespirationCough; may or may not be productive.Hemoptysis.Respiratory rate may be increased.Dyspnea/shortness of breath, orthopnea may be reported.Rales may be present.

Signs & Sympto

ms

1. SIZE OF THE VENTICULAR SEPTAL DEFECT AND THE DEGREE OF RIGHT VENTICULAR OUTFLOW OBSTRUCTION.

2. CYANOSISa.) The shunt through the venticular

septal defect may be from left to right. Many infants with this defedt are not cyanotic at birth, but they develop cyanosis as they grow and as the stenosis becomes relatively more severe.

b.) Cyanosis may at first be observed only with exertion and crying, but during the first few years of life, the child may become cyanotic even at rest.

c.) Infundibular stenosis may be minimal so that cyanosis never develops (“pink tetralogy”)

3. CLUBBING OF THE FINGERS AND TOES4. SQUATTING (a posture

characteristically assumed by children with this defect once they have reached the walking stage)

5. SLOW WEIGHT GAIN6. DYSPNEA ON EXERTION7. HYPOXIC SPELLS, TRANSIENT CEREBAL

ISCHEMIA

•Possible clinical features include:

•The warm mucous membranes are blue, for example the tongue, the inside of the lips

•Central cyanosis increases immediately on exercise which is not the case for peripheral cyanosis

•Often there is polycythaemia with an abnormally high haemoglobin and haematocrit; this must not be confused with neonatal polycythaemia which may mimic cyanosis

•Clubbing is often seen in patients with central cyanosis

•Note that the absolute discriminating feature between central and peripheral cyanosis is obtained from testing the oxygen saturation of arterial blood.

Chronic cyanosis causes clubbing of the digits

Clubbing in Tetralogy of Fallot

DIAGNOSTIC STUDIESWhite Blood Cell (WBC) Count: Leukocytosis indicative of generalized infection, primarilystreptococcal.Hemoglobin (Hg)/Hematocrit (Hct): Reveals actual versus physiological anemia;polycythemia.Maternal Arterial Blood Gases: Provide secondary assessment of potential fetalcompromise due to maternal respiratory involvement.Sedimentation Rate: Elevated in the presence of cardiac inflammation.Maternal Electrocardiogram (ECG): Demonstrates patterns associated with specific cardiacdisorders, dysrhythmias.Echocardiography: Diagnoses mitral valve prolapse or Marfan’s syndrome.Radionuclide Cardiac Imaging: Evaluates suspected atrial or ventricular septal defects,patent ductus arteriosus, or intracardiac shunts.Serial Ultrasonography: Detects gestational age of fetus and possible IUGR.

1. AUSCULTATIONa.) Single second sound(aortic component)b.) Systolic Injection murmur at the second and third interspaces to the left of the sternum.c.)Prominent ejection click heard immediately after the first heart sound

2. CHEST X-RAYa.) Heart size normal b.) Pulmonary segment small and concave (“boot-shaped heart)c.) Diminished pulmonary vascular markings

3. ELECTROCARDIOGRAM- right axis deviation: right venticular hypertrophy

4. CARDIAC CATHETIRIZATION5. ANGIOCARDIOGRAPHY6. LABORATORY DATA

a. Polycythemiab. Increased Hematocrit

•Typical “boot-shaped” heart secondary to RVH and small main pulmonary artery segment

•Pulmonary vascular markings are decreased

Medicines

•Epinephrine 10mcg/kg•Atropine 20mcg/kg•Calcium 10mg/kg•Phenylephrine 2-10mcg/kg•Propanolol 10-50mcg/kg•Volume 5% albumin 10-20ml/kg

COMPLICATIO

NS

1. Congestive heart failure- may occur in newborn but is uncommon beyond infancy.

2. Infective endocardins 3. Cerebral vascular accident (due

to thrombosis or severe hypoxia)4. Brain absces5. Iron defeciency anemia

Treatment Goal

Improve oxygenation of arterial blood.

1. Palliativea) Blalock- Taussig shunt- anastomosis

between the right or left subclavian artery and the right pulmonary artery

b) Watersion Shunt- anastomosis between the posterior lateral aspect of the ascending aorta and the right pulmonary artery.

2. Total Correctiona) Removal of shunt if previously performedb) Total correction is increasingly being

advocated for all infants in whom pulmonary arteries are sufficient size.

NURSING PRIORITIES1. Monitor degree/progression of symptoms.2. Promote client involvement in control of condition and self-care.3. Monitor fetal well-being.4. Support client/couple toward culmination of a safe delivery.

Teaching/LearningPossible history of valve replacement/prosthetic device, mitral valve prolapse, Marfan’ssyndrome, surgically treated/untreated (rare) tetralogy of Fallot

Thank You!...