CHD: tetralogy of fallot Flashcards
cyanotic cardiac defect includes
- VSD
- over-riding aorta
- obstruction to right ventricular outflow:
- subvalvular-> right ventricular infundibular hypertrophy
- valvular pulmonic stenosis
- supravalvular pulmonic stenosis - RVH
TF is most
common cyanotic heart defect diagnosed in adults
TF may also be
aortic arch
atrial septal defect
coronary artery anomalies
Tet spells
- hypercyanotic episodes
- after crying or when awakening-> infant breathes fast and become restless, more cyanotic, begins gasping and then faints
short tet spell
sleep and muscle weakness
long Tet spell
unconsciousness and convulsions
-from prolonged decreased in pulmonary blood flow causing severe symptoms hypoxia and acidosis
how do older children present with TF?
- progressive cyanosis
- dyspnea on exertion
- exercise intolerance
- poor growth
- squatting episodes
- blue skin, gray sclerae, clubbing nails, poor weight gain
cardiac murmurs with TF
systolic ejection murmur of pulmonic stenosis at LUSB
holosytolic murmur at LLSB of VSD
why does squatting help?
-compress arteries in LE and increase aortic resistance and so pulmonary flow is increased
CXR
- boot shaped heart (RV prominence)
- decreased pulmonary vascularity if significant RV obstruction
ECG
RVH, R axis deviation
echo
establishes diagnosis
delineates RV obstruction and severity
where and size of everything
if there is a PDA
cardiac cath
not needed for dx
demonstrates RV tract obstruction, RV trabeculation, infundibular stenosis, location and magnitude of R-> L shunting, anatomy of pulmonary and coronary arteries which is needed for repair
treatment of TF
in an infant with severe pulmonic obstruction: with PDA, give PE1 infusion, O2, fluids, treat hypoglycemia and acidosis
treatment of TF if normal coronary anatomy
- corrective open heart surgery with removal of RV obstruction
- patch graft of VSD
- may have conduction disturbances
treatment of TF for underdeveloped pulmonary arteries
Blalock-Taussig shunt or papillary balloon pulmonary valvuloplasty performed
prophylaxis
SBE
how to avoid a Tet spell in an infant?
- place infant in knee-chest position and comfort
- administer O2 to decrease hypoxia and pul. VR
- morphine (if position and O2 ineffective)-> increases parasymp
- treat acidosis, phenylephrine, propranalol
what do older infants/children/adults need to be evaluated for?
polycythemia
iron deficiency
abnormalities of hemostasis
what if a patient is febrile before surgery?
evaluate for brain abscess or endocarditis
prognosis for untreated TF
- progressive cyanosis-> induces polycythemia to increase oxygen carrying capacity of blood
- iron deficiency
- R-> L shunt through VSD-> brain abscesses
- infective endocarditis likely
- dyspnea and exercise intolerance hamper lifestyle
what can polycythemia cause?
increases risk of cerebral thromboses, hemiplegia, endocarditis, abnormalities of hemostasis
complications of TF
- risk of sudden cardiac death
- ventricular arrhythmias
- RV obstruction may persist or reoccur
- repair of obstruction may leave pulmonary regurgitation leading to RV hypertrophy and failure
- aneurysms at site of repair
- mild AR may occur
