Difference between revisions of "Tetralogy of fallot"

(Tetralogy=)
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== Background ==
 
== Background ==
 
*Most common cyanotic CHD manifesting in post-infancy period. Tet spells are acute episodes of hypoxia and cyanosis caused by right-to-left shunting across the VSD. Patients will present with irritability, agitation, grunting, crying, and central cyanosis.
 
*Most common cyanotic CHD manifesting in post-infancy period. Tet spells are acute episodes of hypoxia and cyanosis caused by right-to-left shunting across the VSD. Patients will present with irritability, agitation, grunting, crying, and central cyanosis.
 +
*During cyanotic spells, there is either:
 +
#Increased pulmonary outflow obstruction and/or
 +
#Decreased systemic vascular resistance leading to right-to-left shunting
 +
 +
*During the spell there is hypercarbia and hypoxemia (which further increases pulmonary vascular resistance).  The process compounds itself creating worsening right-to-left shunting, hyperpnea, right outflow tract obstruction and increased systemic venous return.
 
===Tetralogy===
 
===Tetralogy===
 
#VSD
 
#VSD

Revision as of 14:53, 16 April 2015

Background

  • Most common cyanotic CHD manifesting in post-infancy period. Tet spells are acute episodes of hypoxia and cyanosis caused by right-to-left shunting across the VSD. Patients will present with irritability, agitation, grunting, crying, and central cyanosis.
  • During cyanotic spells, there is either:
  1. Increased pulmonary outflow obstruction and/or
  2. Decreased systemic vascular resistance leading to right-to-left shunting
  • During the spell there is hypercarbia and hypoxemia (which further increases pulmonary vascular resistance). The process compounds itself creating worsening right-to-left shunting, hyperpnea, right outflow tract obstruction and increased systemic venous return.

Tetralogy

  1. VSD
  2. RV outflow obstruction (pulmonic stenosis)
  3. Overriding aorta
  4. RV hypertrophy

Clinical Presentation

  • Systolic ejection murmur along the left sternal border[1]
  • Cyanosis worse during feeding and crying[1]
  • May squat to relieve symptoms: increases afterload and decreases shunt[1]
  • Acute respiratory distress (Tet Spells) due to increased right outflow tract obstruction[1]

Work-Up

  • Echo
  • CXR: shows the classic “boot-shaped” heart

Differential Diagnosis

Congenital Heart Disease Types

Treatment

  • Definitive Treatment: Surgery
  • Acute Presentation (Tet spell):
  1. Valsalva
  2. Place in knee-chest position
    1. Increases SVR > more blood into pulm ciruclation
  3. Morphine 0.1-0.2Mg/kg IV or IM
    1. Mechanism of action unclear
    2. Consider Intranasal Fentanyl
  4. Fluids IV
    1. Improves RV filling
  5. Beta blockers IV
    1. Relaxation of RVOT
  6. Phenylephrine
    1. Similar to knee-chest position
  7. Prostaglandin E1 0.1 mg/kg bolus followed by infusion 0.05 to 0.1 mg/kg/min
    1. Maintains the ductus
    2. Side Effects: Hypotension, Bradycardia, Seizures and Apnea

See Also

Source

  1. 1.0 1.1 1.2 1.3 Horeczko T, Inaba AS: Cardiac Disorders; in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 8. St. Louis, Mosby, Inc., 2014, (Ch) 171: p 2139-2169.
  2. Knipe K et al. Cyanotic congenital heart diseases. Radiopaedia. http://radiopaedia.org/articles/cyanotic-congenital-heart-disease