8/18- LAB: Pathology of Congenital Heart Disease Flashcards
Describe the circuit of fetal circulation
- Ductus venosus takes oxygenated UV blood to suprahepatic IVC
- IVC blood is directed across PFO to LA-LV-Ascending aorta
- SVC blood directed to RV-PA
- High pulmonary vascular resistance directs PA blood to PDA and descending aorta
- Umbilical arteries take blood back to placenta
Describe the postnatal transitional circulation
- Closure of fetal shunts
- Gradual decrease in pulmonary vascular resistance
What is patent ductus arteriosus? Consequences?
Left to right shunt (from aorta to pulmonary artery)
Consequences:
- Increased PA bloodflow -> LV dilation
- Increased PA pressure -> RV hypertrophy
- Increased risk for pulmonary HTN!
Closure of the ductus arteriosus occurs how?
Functional closure (intimal cushions*)
- 1-2 d muscular contraction
- Followed by:
Anatomic closure
- Ductal ligament “ligamentum arteriosum”
- 6 wks - 3 mo
Treatment of PDA?
- Pharmacologic: Indomethacin (PGE Inhib)
- Percutaneous catheterization: occlusion devices
- Surgical ligation
What is ductus dependent congenital heart disease?
Certain lesions that may be asymptomatic in-utero will lead to early death following birth due to closure of the fetal shunts, largely the ductus arteriosus.
- In this scenario, administration of Prostaglandin E (PGE) to maintain ductal patency is “life saving”.
Clinical Case)
- Full term male, uncomplicated birth Hx
- At 2 d, he becomes fussy, feeding poorly, dusky blue nail beds and grunting with tachypnea
- Parents take to ER but he collapses and becomes unresponsive en route
- In ER, he has tachycardia with weak pulses and cool skin
These signs/symptoms point to what conditions/diseases?
Cyanosis is indicated by blue nailbeds
Congestive Heart Failure is indicated by:
- “Fussy”, feeding poorly
- Grunting with tachypnea
Shock is indicated by:
- Collapsing, unresponsive tachycardia
- Weak pulses and cool skin
Heart structure:
- ASD
- No continuity between LV and aorta; there is no aortic valve. LV ends blindly at the base of the aorta
- Patent ductus arteriosus (PDA)
Think ductus dependent lesion with what part of the Hx?
Onset of symptoms at 2 days
What is shown here?
- ASD
- No continuity between LV and aorta; there is no aortic valve. LV ends blindly at the base of the aorta
- Patent ductus arteriosus (PDA)
Case)
If there is no aortic valve; the LV ends blindly at the base of the aorta. The aortic valve is described as?
A. Hypoplastic
B. Atretic
C. Dysplastic
D. Atrophic
If there is no aortic valve; the LV ends blindly at the base of the aorta. The aortic valve is described as?
A. Hypoplastic
B. Atretic
C. Dysplastic
D. Atrophic
Hypoplastic- decreased size
Atretic- imperforate; no opening AT ALL
Dysplastic- poorly formed
Atrophic- started normally sized, but decreased due to physiologic/other reasons
Case)
The left ventricle and ascending aorta are described as?
A. Hypoplastic
B. Atretic
C. Dysplastic
D. Atrophic
The left ventricle and ascending aorta are described as?
A. Hypoplastic
B. Atretic
C. Dysplastic
D. Atrophic
Case)
Which of the following is true?
A. The baby was cyanotic because of a right to left shunt at the foramen ovale.
B. The baby was cyanotic because of a left to right shunt at the foramen ovale.
C. The baby was cyanotic because of a left to right shunt at the ductus arteriosus.
D. The baby was cyanotic because of a right to left shunt at the ductus arteriosus.
Which of the following is true?
A. The baby was cyanotic because of a right to left shunt at the foramen ovale.
B. The baby was cyanotic because of a left to right shunt at the foramen ovale.
C. The baby was cyanotic because of a left to right shunt at the ductus arteriosus.
D. The baby was cyanotic because of a right to left shunt at the ductus arteriosus.
Case)
The ductus arteriosus(*) provides bloodflow to:
A. The systemic circulation
B. The systemic and coronary circulation
C. The pulmonary circulation
D. All of the above
The ductus arteriosus(*) provides bloodflow to:
A. The systemic circulation
B. The systemic and coronary circulation
C. The pulmonary circulation
D. All of the above
- Coronary arteries can’t get bloodflow from aorta (no flow across it or valves); flow actually going backwards down aorta to coronary arteries
Case) With closure of the ductus arteriosus:
A. This baby will develop shock.
B. his baby will develop worsening cyanosis.
C. This baby will have congestive heart failure.
D. All of the above.
Case) With closure of the ductus arteriosus:
A. This baby will develop shock.
B. his baby will develop worsening cyanosis.
C. This baby will have congestive heart failure.
D. All of the above.
In this case, the obstructive lesion in the aortic arch is what?
Aortic coarction that sits opposite the entry of the PDA(*)
- In this position it is called jxutaductal
What is surgical repair look like in hypoplastic left heart syndrome?
Occurs in stages:
- Norwood-Glenn-Fontan
- Occurs over first 2 years of life
Many pts with full repair of Hypoblastic Left Heart Syndrome typically develop what?
RT heart failure
- require heart transplant
What is transposition of the great arteries?
- RV pumps into aorta while LV pumps into pulmonary a.
- Need ductus to get oxygenated blood to body!
Treatment for TGA?
Arterial switch repair
- Connect aorta back to LV and pulmonary artery back to the right
- Have to leave the right valve (with coronary artery outflow) so take button of coronary arteries off and reattach to the L (patch the holes left behind)
- Arterial switch repair is performed in the 1st 2 wks of life while the LV still has its muscle mass form the high pulmonary vascular resistance of the fetus (preferred repair method)
- (before this, an “atrial switch” was done by excising the atrial septum and placing a tortuous patch to redirect pulmonary venous blood to the RV and systemic venous blood to the LV
How common is TGA?
- One of the most common congenital heart anomalies seen in adults (most repaired with “atrial switch”)
