Bernstein #1 Flashcards
What are the 3 most common cardiac problems in PEDS
- Bicuspid aortic valve
- VSD
- ASD (secundum)
What is the most common cyanotic lesion?
Tetralogy of fallot 6%
In the 1st week of life, what is the most frequent cyanotic defect?
D-transposition of the great arteries
What is levocardia?
Heart in right place, but other organs are reversed
What is dextrocardia?
Heart pointed wrong direction to the right.
What is mesocardia?
Midline heart
What is situs solitus?
Normal arrangement of organs
-Liver right
Stomach left
What is situs inversus?
complete reversal of organs
What is situs ambiguous?
Reversal of some organs
Anything other than situs solitus (normal arrangement) suggest what?
High likelihood of Congenital heart disease
Fetal circulation is ______ rather than in ________.
Parallel
series
in fetal circulation what delivers blood to both pulmonary and systemic circulation?
Right ventricle
In fetal circulation, the LV sends blood where?
Systemic
Placental circulation
In fetal circulation where does O2 blood come from?
Placenta
What route does placental blood take to bypass liver and go straight to the IVC?
Ductus venosus
in fetal circulation, What causes 90% of blood from the RV to pass the PA and head straight to the descending aorta?
- Ductus Arteriosus
- High PVR
What is preferential streaming in fetal circulation?
Umbilical venous blood w/ higher O2 content is given to the Brain, Heart and upper limbs.
ascending aorta O2 sats
pO2 = 20-22 mmHg O2 = 65%
Descending aorta sats
pO2 = 20-22 mmHg O2 = 55%
What facilitates O2 uptake in the placenta?
Lower p50 of fetal hemoglobin
In fetal circulation which ventricle has a higher output?
RV
- 1.3:1 RV/LV output
Why does RV have more output in fetal circulation?
Greater size and thickness
How much output does the RV have in fetal circulation?
450 ml/kg/min
During transitional circulation, an increase of alveolar O2 from spontaneous ventilation leads to what?
- ↓ Pulmonary vascular resistance
- ↑ pulmonary blood flow
What increase as the placenta is gone?
SVR
What causes the drop in systemic venous return to the IVC?
Umbilical venous flow is removed
What increases LA pressure during transitional circulation?
Increased pulmonary blood flow and pulm venous return
As LA pressure exceeds RA pressure what is closed? and what stops?
Foramen Ovale
Atrial shunting
When does the ductus arteriosus close?
10-15 hours after birth
What 3 things cause closure of the ductus arteriosus?
- ↑ O2 tension
- ↓ prostaglandins
- Bradykinin
FO can reopen if what happens?
Increased RA pressure
What can cause increased RA pressure?
- Crying
- Pain
- Hypoxia
- hypercarbia
- acidosis
- Lung disease
- sepsis
How long does it take to close the FO and how does it happen?
3 months to a year
-Septum primum and septum secundum adhere
When does functional and antomic closure of the ductus arteriosus happen?
72 hours of life
- 1 to 3 months
Anatomic closure of the ductus arteriosus happens with the formation of what?
ligamentum arteriosum
What are CHD patients dependent on?
Ductus arteriosus patency
What can be done to keep ductus arteriosus patent?
- Prostglandin E1 (alprostadil) infusion
- ↓ O2 tension
Side effects of alprostadil
- Resp depression
- Apnea
- Fever
- Seizures
Signs of PDA
- Hyperactive precordium
- Bounding pulse
- Wide pulse pressure
- Hepatomegaly
- tachypnea
- Tachycardia
What med to close PDA?
Indomethacin (prostaglandin inhibitor)
What are normal blood volumes for premie, < 3 months, 3-12 mo, and > 12 months?
Premie = 100-120 ml/kg 12 = 70
Why do increases in preload and afterload have negligible effects on PEDS CO?
- Fewer contractile elements
- Deficiency of elastic elements
- Reduced compliance
What is ventricular interdependence?
-Change in ventricular pressure to 1 ventricle effects the other
What causes ventricular interdependence?
- Low ventricle compliance
- Equal ventricle muscle mass
Why would you pretreat a neonate w/ atropine prior to intubation?
Incomplete autonomic innervation leads to bradycardia upon stimulation.
-CO is dependent on HR
What does not change in a newborn?
Stroke volume
The hallmark of intravascular fluid depletion in neonates and infants is?
hypotension without tachycardia
A concern for paradoxical air embolism may occur in the neonate because of?
patent foramen ovale
What is your map goal in the first few weeks of life?
estimated gestational age in weeks
Normal VS for infants.
HR 120-160
RR 30-60
Premie bp 5-/25
Neonate bp 7-/40
When does PVR reach adult levels?
6 months
What environmental factors can lead to CHD?
- Maternal disease
- Maternal Meds
- Drug abuse
- Maternal diabetes
- ETOH
What do volume overload lesions cause?
Left to right shunting
What are the 5 volume overload lesions?
- ASD
- VSD
- AVSD
- PDA
- Truncus Arteriosus
Where can volume overload lesions occur?
- Atrial
- Ventricular
- Great artery
What happens if shunt is proximal / distal to the mitral valve?
Proximal = right heart dilation Distal = Left heart dilation
How to treat overload lesions
-diuretic therapy
-Afterload reduction
Both control pulmonary overcirculation
What are the 3 types pf ASD?
- Secundum
- Primum
- Sinus venosus
What is most common ASD and where is it found?
- Secundum
- Fossa ovalis
Where is the primum located and what is it a form of?
- Lower in atria
- ASVD & MV cleft
What is the least common ASD, where is it located and what is it associated with?
- Sinus venosus
- High in atria
- Partial anomalous venous return
Clinical symptoms of ASD
- Most asymptomatic
- Fatigue
- Cyanosis w/ pulm HTN
What causes the diastolic and systolic murmurs in ASD?
Systolic - ↑ flow across pulmonary valve
Diastolic - ↑ flow across tricuspid
How do you treat ASD?
Closure if Qp:Qs ratio is > 2:1
When are ASD closed?
- elective between 2-5
- Earlier w/ CHF or pulm HTN
When is it considered too late to close an ASD?
-Pulm HTN w/ shunt reversal
Is endocarditis prophylaxis required for ASD?
No
what are the 4 types of VSD?
- Membranous
- Infundibular
- Muscular
- AVSD
What is the most common VSD
Membranouos
VSD that involves RV outflow tract.
Infundibular
Which VSD can be single or multiple?
Muscular
AVSD almost always involves what?
AV valvular abnormalities
What causes the left to right shunt in VSD?
PVR being greater than SVR
What do VSD lead too?
- ↑ RV and pulmonary pressure
- Hypertrophy of LA and LV
What is considered a small - moderate VSD, and how do they close?
- 3-6mm
- 50% will close spontaneously by 2yo
______ to ________ VSD always have symptoms and require surgical repair
moderate
Large
What symptoms are seen w/ VSD?
- CHF
- Failure to thrive
- Resp infections
- exercise intolerance
- hyperactive precordium
What is needed for small VSD?
-endocarditis prophylaxis
What is needed for medical treatment of symptomatic VSD?
- afterload reduction
- Diuretics
What are the surgical indications for VSD\?
- Large w/ medically uncontrolled symptoms
- Age 6-12 months = pulm htn
- Age >24 months = Qp:Qs ratio >2:1
Why do supracristal VSD of any size require surgery?
Risk of developing AV insuffiency
AVSD results from what?
Incomplete fusion of endocardial cushions
AVSD is more common in what genetic disease?
Down’s syndrome 25%
Incomplete AVSD may be indistinguishable from what?
ASD
AVSD symptoms
- CHF in infants
- Pulmonary infections
- Failure to thrive
- fatigue
- Late cyannosis
Surgery is always required with what CHD?
AVSD
-done during infancy
How to treat AVSD
- Treat congestive symptoms
- Pulmonary Banding <5kg
