CHD: tetralogy of fallot

Question 1

cyanotic cardiac defect includes

Answer 1

1. VSD
2. over-riding aorta
3. obstruction to right ventricular outflow:
   - subvalvular-> right ventricular infundibular hypertrophy
   - valvular pulmonic stenosis
   - supravalvular pulmonic stenosis
4. RVH

Question 2

TF is most

Answer 2

common cyanotic heart defect diagnosed in adults

Question 3

TF may also be

Answer 3

aortic arch
atrial septal defect
coronary artery anomalies

Question 4

Tet spells

Answer 4

• hypercyanotic episodes
• after crying or when awakening-> infant breathes fast and become restless, more cyanotic, begins gasping and then faints

Question 5

short tet spell

Answer 5

sleep and muscle weakness

Question 6

long Tet spell

Answer 6

unconsciousness and convulsions

-from prolonged decreased in pulmonary blood flow causing severe symptoms hypoxia and acidosis

Question 7

how do older children present with TF?

Answer 7

• progressive cyanosis
• dyspnea on exertion
• exercise intolerance
• poor growth
• squatting episodes
• blue skin, gray sclerae, clubbing nails, poor weight gain

Question 8

cardiac murmurs with TF

Answer 8

systolic ejection murmur of pulmonic stenosis at LUSB

holosytolic murmur at LLSB of VSD

Question 9

why does squatting help?

Answer 9

-compress arteries in LE and increase aortic resistance and so pulmonary flow is increased

Question 10

CXR

Answer 10

• boot shaped heart (RV prominence)

- decreased pulmonary vascularity if significant RV obstruction

Question 11

ECG

Answer 11

RVH, R axis deviation

Question 12

echo

Answer 12

establishes diagnosis
delineates RV obstruction and severity
where and size of everything
if there is a PDA

Question 13

cardiac cath

Answer 13

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

Question 14

treatment of TF

Answer 14

in an infant with severe pulmonic obstruction: with PDA, give PE1 infusion, O2, fluids, treat hypoglycemia and acidosis

Question 15

treatment of TF if normal coronary anatomy

Answer 15

• corrective open heart surgery with removal of RV obstruction
• patch graft of VSD
• may have conduction disturbances

Question 16

treatment of TF for underdeveloped pulmonary arteries

Answer 16

Blalock-Taussig shunt or papillary balloon pulmonary valvuloplasty performed

Question 17

prophylaxis

Answer 17

SBE

Question 18

how to avoid a Tet spell in an infant?

Answer 18

• 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

Question 19

what do older infants/children/adults need to be evaluated for?

Answer 19

polycythemia
iron deficiency
abnormalities of hemostasis

Question 20

what if a patient is febrile before surgery?

Answer 20

evaluate for brain abscess or endocarditis

Question 21

prognosis for untreated TF

Answer 21

• 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

Question 22

what can polycythemia cause?

Answer 22

increases risk of cerebral thromboses, hemiplegia, endocarditis, abnormalities of hemostasis

Question 23

complications of TF

Answer 23

• 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