II. Epidemiology

  1. Incidence: 10-15% of Congenital Heart Disease
  2. Most common cause of CHD outside infancy

III. Pathophysiology: General

  1. Cyanotic Congenital Heart Disease
    1. Secondary to Right-To-Left Shunt (related to VSD and often pumonary stenosis)
    2. May present in first month of life with Cyanosis and severe pulmonic stenosis
      1. Treated with PGE-1 infusion (as other cyanotic ductus dependent lesions)
  2. Four components
    1. Primary features responsible for symptoms
      1. Large Ventricular Septal Defect (VSD)
      2. Right outflow tract obstruction
    2. Other features
      1. Right Ventricular Hypertrophy
      2. Overriding aorta

IV. Pathophysiology: Tet Spell (hypercyanotic episode)

  1. Inciting event (e.g. crying or feeding)
    1. Increased pulmonary outflow obstruction
    2. Decreased systemic vascular resistance
  2. Results in Right-to-left Shunting
    1. Hypercarbia
    2. Hypoxemia
  3. Results in Increased pulmonary vascular resistance
    1. Worsens right-to-left shunting in cycles of worsening hypercarbia and Hypoxemia
  4. Management (see below) goals
    1. Increase systemic vascular resistance (e.g. knees to chest, Supplemental Oxygen)
    2. Decrease hyperpnea (deep, rapid breathing)

V. Associated conditions

  1. Right aortic arch (25%)
  2. Atrial Septal Defect (15%)
  3. Absent pulmonary valve
  4. Pulmonary atresia
  5. Pulmonary stenosis
  6. Atrioventricular septal defect
  7. Left superior vena cava to coronary sinus

VI. Signs: Presentation "Tet Spell"

  1. Hypercyanotic, intermittent episode
  2. Occurs in early morning with awakening
  3. Symptoms
    1. Hyperpnea
    2. Irritibility
    3. Central Cyanosis
    4. Grunting

VII. Signs

  1. Systolic ejection murmur at left sternal border
    1. Grade III+ intensity, harsh Systolic Murmur
    2. Murmur diminishes in intensity during "Tet Spell"
  2. Single S2 Heart Sound

IX. Labs

  1. Arterial Blood Gas
    1. Normal arterial pH
    2. Normal arterial pCO2
    3. Low arterial pO2

X. Imaging

  1. Chest XRay
    1. Heart size normal or small
    2. Narrow mediastinum
    3. Heart may appear "boot shaped" in classic presentation
  2. Echocardiogram
    1. Large Ventricular Septal Defect (VSD)
    2. Right outflow tract obstruction
    3. Right Ventricular Hypertrophy
    4. Overriding aorta

XI. Management: Conservative of "Tet Spells"

  1. Knee-to-chest position
    1. Similar to older children who squat during episodes
    2. Place infant in mothers arms with their knee flexed against their chest
    3. Decreases venous return and excessive Preload
  2. Avoid upsetting child
    1. Delay IV starts during initial stabilization
    2. Keep child with parent or guardian
  3. Supplemental Oxygen
    1. Decreases pulmonary vascular resistance (PVR)
  4. Opioid Analgesics
    1. Quiets child, reduces Tachypnea and reduces systemic venous return
    2. Morphine Sulfate 0.1 to 0.2 mg/kg SQ or IM (or 0.05 to 0.1 mg/kg IV)
    3. Fentanyl 1.5 to 2 mcg/kg intranasal via mucosal atomization device (MAD Device)
    4. Ketamine 1 to 2 mg/kg IV
  5. Volume expansion
    1. Consider Normal Saline bolus (10-20 ml/kg)
    2. Increases Preload and improves right end-diastolic volume
  6. Advanced medications
    1. Consult pediatric cardiology
    2. Phenylephrine
      1. Increases systemic vascular resistance
      2. Dose: 0.2 mg/kg IV
    3. Beta Blocker
      1. Reduces right ventricular outflow obstruction
      2. Acute: Propranolol 0.05 to 0.01 mg/kg IV
      3. Chronic: Propranolol 1 to 4 mg/kg/day PO

XII. Management: Surgery

  1. Subclavian to pulmonary artery shunt (Blalock-Taussig)
    1. Palliative or temporizing method
  2. Definitive, total repair
    1. Repair as newborn or at age 3 years
    2. Ventricular Septal Defect patch
    3. Right ventricular outflow tract widening

XIII. Complications: Without repair (inoperable cases)

XIV. Complications: Post-surgical correction

  1. Arrhythmia
  2. Right ventricular insufficiency
    1. Right Ventricular failure
    2. Pulmonary insufficiency
  3. Left ventricular insufficiency
    1. Left Ventricular Failure
    2. Aortic Insufficiency

XV. Prognosis

  1. Survival post-surgical repair: >95%
  2. Cognitive development may be impaired

XVI. References

  1. Civitarese and Crane (2016) Crit Dec Emerg Med 30(1): 14-23
  2. Cyran (1998) PREP review lecture, October, Phoenix
  3. Merenstein (1994) Pediatrics, Lange
  4. Tsze and Spangler in Herbert (2015) EM:Rap 15(4): 2-3
  5. Saenz (1999) Am Fam Physician 59(7):1857-66 [PubMed]

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Ontology: Tetralogy of Fallot (C0039685)

Definition (MSH) A combination of congenital heart defects consisting of four key features including VENTRICULAR SEPTAL DEFECTS; PULMONARY STENOSIS; RIGHT VENTRICULAR HYPERTROPHY; and a dextro-positioned AORTA. In this condition, blood from both ventricles (oxygen-rich and oxygen-poor) is pumped into the body often causing CYANOSIS.
Definition (NCI) A congenital heart disorder characterized by the presence of the following four abnormalities: ventricular septal defect, pulmonary stenosis, overriding aorta, and right ventricular hypertrophy.
Definition (CSP) combination of congenital cardiac defects consisting of pulmonary stenosis, interventricular septal defect, dextroposition of the aorta so that it overrides the interventricular septum and receives venous as well as arterial blood, and right ventricular hypertrophy.
Concepts Congenital Abnormality (T019)
MSH D013771
ICD9 745.2
ICD10 Q21.3
SnomedCT 156913009, 204305006, 204307003, 268177006, 86299006
English Fallot Tetralogy, Fallot's Tetralogy, Fallots Tetralogy, Tetralogy, Fallot's, Tetralogy, Fallots, Tetralogy of Fallot NOS, Tetralogy of Fallot unspecif., Tetralogy of Fallot, unspecified, TETRALOGY OF FALLOT, Tetralogy of Fallot, tetralogy of Fallot, tetralogy of Fallot (diagnosis), Fallot tetralogy, Fallot tetralogy of, Tetralogy of Fallot [Disease/Finding], fallot of tetralogy, fallot's tetralogy, tetralogy of fallot, fallot tetralogy, fallots tetralogy, tetralogy fallot, Tetralogy, Fallot, TOF, Tetralogy of Fallot NOS (disorder), Tetralogy of Fallot, unspecified (disorder), Fallot's tetralogy, TOF - Tetralogy of Fallot, Subpulmonic stenosis, ventricular septal defect, overriding aorta, AND right ventricular hypertrophy, Tetralogy of Fallot (disorder), Fallot; tetralogy, tetralogy; Fallot, Subpulmonic stenosis, ventricular septal defect, overriding aorta, and right ventricular hypertrophy, Ventricular septal defect with pulmonary stenosis or atresia, dextraposition of aorta, and hypertrophy of right ventricle, Tetralogy of fallot
German Tetralogie von Fallot, Fallot Tetralogie, Fallot-Tetralogie, Tetralogie, Fallot-
Spanish Fallot, tetralogía de, tetralogía de Fallot, no especificada, tetralogía de Fallot, SAI, tetralogía de Fallot, SAI (trastorno), tetralogía de Fallot, no especificada (trastorno), estenosis subpulmonar, defecto del tabique ventricular, cabalgamiento de aorta E hipertrofia del ventrículo derecho, estenosis subpulmonar, defecto del tabique ventricular, cabalgamiento de aorta e hipertrofia del ventrículo derecho, tetralogía de Fallot (trastorno), tetralogía de Fallot, Tetralogía de Fallot
Swedish Fallots tetrad
Japanese ファローシチョウショウ, ファローシチョウ, Fallot四徴, Fallot四徴症, ファロー四徴, ファロー四徴症, 先天性心奇形四徴, 心奇形四徴
Czech Fallotova tetralogie
Finnish Fallot'n tetralogia
Russian TETRALOGIIA FALLO, TETRADA FALLO, FALLO TETRADA, ТЕТРАДА ФАЛЛО, ТЕТРАЛОГИЯ ФАЛЛО, ФАЛЛО ТЕТРАДА
Korean 팔로의 사징후
Croatian FALLOTOVA TETRALOGIJA
Polish Tetralogia Fallota, Zespół Fallota
Hungarian Fallot tetralógia, Fallot-tetralogia, Fallot-tetralógia, Fallot féle tetralogia
Norwegian Fallots tetrade, Tetrade, Fallots
Dutch Fallot; tetralogie, tetralogie; Fallot, tetralogie van Fallot, Fallot, tetralogie van, Fallot-tetralogie, Tetralogie van Fallot
French Tétralogie de Fallot
Italian Tetralogia di Fallot
Portuguese Tetralogia de Fallot