Congenital Heart Defects Flashcards
inciting factors to CHD
Acidosis, sepsis, hypothermia, hypoxia, hypercarbia: force fetal circulation to persist after birth
Most neonates who are critically ill from CHD have one or more of these inciting factors
Most congenital heart defects are the result of _____
genetic predisposition and environmental factors
Environmental factors: drugs, viral infection, maternal diabetes, maternal alcohol abuse
Normal Pressure in Right Atrium and Right Ventricle in newborns vs. children
RA (newborn): 0-4 mmHg
RA (child): 3-6 mmHg
RV (newborn): 65-80/0-6 mmHg
RV (child): 20-30/3-6 mmHg
Normal Pressure in Pulmonary Artery and Pulmonary Vein in newborns vs. children
Pulmonary Artery (newborn): 65-80/35-50 mmHg
Pulmonary Artery (child): 20-30/8-12 mmHg
Pulmonary Vein (newborn): 6-9 mmHg
Pulmonary Vein (child): 6-8 mmHg
Normal Pressure in Left Atrium and Left Ventricle in newborns vs. children
Left Atrium (newborn): 3-6 mmHg
Left Atrium (child): 6-8 mmHg
Left Ventricle (newborn): 65-80/0-6 mmHg
Left Ventricle (child): 90-120/6-12 mmHg
Normal Pressure in aorta newborns vs. children
Newborn: 65-80/45-60 mmHg
Child: 90-120/50-60 mmHg
PA wedge = ____
pulm venous pressure= LA if no obstruction
What decreases pulmonary vascular resistance?
Hypocapnia
Pulmonary vasodilator (nitric oxide)
What increases SVR?
sympathetic stimulation
vasoconstrictor
hypothermia
What increases pulmonary vascular resistance?
hypoxemia
hypercapnia
high hematocrit
positive pressure ventilation
metabolic acidosis
alpha-adrenergic stimulation
What decreases SVR?
vasodilators
spinal and epidural anesthesia
deep general anesthesia
hyperthermia
What is the normal PVR to SVR ratio?
1:10-1:20
If SVR increases relative to PVR then ___ happens
pulm BF increases resulting in decrease systemic BF
If PVR increases relative to SVR then ___ happens
pulm BF decreases resulting in increase in systemic BF
What condition(s) are associated with increased pulmonary blood flow?
- atrial septal defect
- ventricular septal defect
- patent ductus arteriosus
- atrioventricular canal
(all of which are acyanotic lesions)
What condition(s) are associated with obstruction to blood flow from ventricles?
coarctation of aorta
What condition(s) are associated with decreased pulmonary blood flow?
Tetralogy of Fallot
What condition(s) are associated with mixed blood flow?
Transposition of Great Arteries
Hypoplastic Left Heart Syndrome
What are lesions that increase pulmonary blood flow?
Acyanotic Lesions:
-Atrial Septal Defect (ASD)
-Ventricular Septal Defect (VSD)
-Patent Ductus Arteriosus (PDA)
-Atrioventricular Canal Defect
Cyanotic Lesions:
-Transposition of the Great Arteries (TGA)
Atrial Septal Defect is a communication between ___.
What kind of shunt is it?
the LA and RA due to a defect in the intra-atrial septum
L to R shunt
ASDs are classified by ____.
location
Ostium secundum β comprise 80% of ASDs
Ostium Primum- 15 % of ASDβs
Surgical Therapy:
Primary, patched, or device closure
Anesthesia Management:
Inhalation induction tolerated well
Ventricular Septal Defect (VSD) allows communication between ____.
?Types
RV and LV
Types:
Subpulmonary or supracristal defects
Membranous or perimembranous defects- approximately 80% of all VSDs
Muscular defects
With VSD, what impacts the size of the defect?
Size of the defect = magnitude of shunting
Small= restrictive
Large=non-restrictive
Shunt depends on PVR to SVR ratio
Normally, VSD produce L -> R shunt
If PVR to SVR ratio is higher then near normal pulmonary BF resulting in R -> L shunt (Eisenmenger syndrome)
Surgical Treatment of VSD
Surgical Therapy
Large VSDs are corrected early in childhood
Device, patch, or stitch closure
Post-op risk of EKG changes secondary to edema or sutures (Complete heart block, junctional, junctional ectopic tachycardia (JET))
Patent Ductus Arteriosus connects _____.
What kind of shunt is it?
the main pulmonary trunk with the proximal descending aorta
10 % of all congenital heart defects
Girls > boys
L to R shunt
PVR:SVR ratio dependent when PDA is large
Treatment of Patent Ductus Arteriosus
Indomethacin infusion
Closure in catheterization lab
Surgical Therapy
Ligation via left thoracotomy or video-assisted thorascopic surgery
First closure of PDA done at BCH with Robert Gross (surgeon) and Betty Lank (nurse anesthetist) in 1938
**At risk for injuring recurrent laryngeal nerve