Congenital Heart Disease Flashcards
Describe the fetal circulation
Umbilical vein brings O2 rich blood to IVC
O2 rich blood goes into right atrium at medium intensity and Eustachian valve pushes it across foramen ovale to left atrium
Blood that doesn’t go across foramen ovale mixes with venous blood from SVC and goes to lungs via pulmonary artery
However, lungs don’t contain oxygen and are high pressure, so blood goes through ductus arteriosus into aorta. Pulmonary arteries provide enough blood to lung tissue to keep lungs alive.
Blood through ductus arteriosus mixes with oxygenated blood in aorta and goes to systemic circulation
What changes occur to fetal circulation after birth?
Pulmonary vascular resistance decreases with first breaths
Blood goes to low resistance pulmonary vasculature, effectively closing the ductus arteriosus after a few days
Rush of blood back from pulmonary veins helps to shut the foramen ovale
What are the most common types of shunts?
Atrial septal defect (ASD)
Ventricular septal defect (VSD)
Patent ductus arteriosus (PDA)
What are the types of atrial septal defects?
Secundum
Primum
Sinus venosus
Coronary sinus
What is the most common congenital heart defect in adults?
Secundum atrial septal defect
What is the end result of all of the atrial septal defects?
Shunt from LA to RA = volume overload of RA
What are long term effects of left to right shunt?
RA volume overload –> RV volume overload –> pulmonary arterial hypertension
What is Eisenmenger syndrome?
When pulmonary hypertension and pressures in right side become so great that it leads to reverse shunting
(blood from right heart to left heart since right sided pressures now exceed left)
What will be detected on physical exam of patient with ASD?
Dyspnea
Possible A fib
Systolic murmur due to excess flow across pulmonary valve
Fixed splitting of S2
Describe the phenomenon of physiologic splitting of S2 and the fixed splitting of S2 seen in ASD
Physiologic splitting: upon inspiration, get increased blood return to right heart, and when its more full it takes slightly longer for the pulmonary valve to close
- Will hear split of S2 (aortic valve close, then pulm valve close)
ASD fixed splitting: have perpetual excess volume in right side, so have perpetual conditions of inspiration, causing split S2 all the time
What is the most common congenital heart defect in pediatric population?
Ventricular septal defect (VSD)
What will be detected on physical exam of patient with VSD?
Constant murmur from constant LV –> RV flow
Increased pulmonary artery pressure due to RV volume overload
Potential cardiomegaly from RV dilitation
What is a coarctation of the aorta?
Narrowing in proximal descending aorta, causing pressure overload
What does coarctation have such a poor prognosis?
Can cause other severe effects like: Aortic aneurysm Aortic dissection CHF Premature CAD
What additional condition is often associated with coarctation of the aorta?
Bicuspid aortic valve
