Fetal to Neonatal Transition; Acyanotic CHD - ASD Flashcards
___% of umbilical venous blood enters the hepatic circulation
50
IVC –> right atrium –> ___ valve –> foramen ovale –> left atrium –> left ventricle –> ascending aorta
Eustachian
SVC –> right atrium –> tricuspid valve –> right ventricle –> pulmonary artery –> ___
5% enters the lungs, majority goes through the ductus arteriosus –> descending aorta
Total fetal cardiac output
~450mL/kg/min
Descending aortic blood: ___% returns to placenta, ___% perfuses fetal organs and tissues
65, 35
Bring about rapid decrease in pulmonary vascular resistance at birth
1) Mechanical expansion of lungs 2) Increase in arterial pO2
Removal of low-resistance placental circulation at birth brings about
1) Increase in systemic vascular resistance 2) Closure of the ductus venosus
Reverses blood flow through the ductus arteriosus at birth
Increase in systemic vascular resistance, decrease in pulmonary vascular resistance
Constricts and eventually closes the ductus arteriosus during the neonatal period
High arterial pO2
Remnant of the ductus arteriosus
Ligamentum arteriosum
Functionally closes the flap of the foramen ovale
Increase in left atrial volume from increase in return of blood from the lungs
Functional closure of the ductus arteriosus in the normal neonate
10-15 hours of life
Newborn cardiac output
350ml/kg/min
Foramen ovale functionally closes by
3rd month of life
CHD associated with Holt Oram syndrome
ASD
T/F An isolated valve-incompetent PFO is hemodynamically significant and is considered an ASD
F
T/F An isolated PFO does not require surgical treatment
T
PFO device closure is considered when
(+) history of thromboembolic stroke
MC form of ASD
Ostium secundum defect in the region of the fossa ovalis
T/F Secundum ASD is associated with structurally normal AV valves
T
With large defects, ratio of pulmonary to systemic flow (Qp:Qs) is usually
2:1 to 4:1
T/F Despite large pulmonary blood flow, pulmonary arterial pressure in cases of ASD is usually normal because of the absence of high-pressure communication between pulmonary and systemic circulation
T
T/F A child with ostium secundum ASD is most often asymptomatic
T
CHD: Widely split S2 with fixed splitting
ASD
CHD: Systolic ejection murmur best heard at left mid to upper sternal border
ASD
SEM heard in ASD is brought about by
Increased flow across the right ventricular outflow tract into the pulmonary artery
T/F SEM heard in ASD is brought about by flow across the ASD
F, flow across the ASD is low in pressure
Echo findings characteristic of RV volume overload
1) Increased RV end-diastolic dimension 2) Flattening and abnormal motion of the ventricular septum
T/F Patients with classic features of a hemodynamically significant ASD on PE and chest radiography in whom echo shows an isolated secundum ASD need to undergo diagnostic cath before repair
T
Surgical or transcatheter device closure of ASD is advised for
1) All symptomatic patients 2) Asymptomatic patients with Qp:Qs ratio of at least 2:1 3) RVE
Timing for elective closure of ASD
After the 1st year and before entry into school
Procedure of choice for ASD closure
Percutaneous catheter device closure
T/F Small- to moderate-sized ASDs detected in TERM infants may close spontaneously
T
T/F IE is common in ASD hence antibiotic prophylaxis for isolated secundum ASD is recommended
F, EXTREMELY RARE
