EMBRYO HEART DEFECTS

Question 1

How are cardiac congenital abnormalities classified ?

Answer 1

Cyanotic (L-R shunt or no shunt)

Acyanotic

No shunt (Anomalies of aortic arches or coarctition of aorta)

Question 2

PDA (Patent Ductus Arteriosus)-cyanotic or acyanotic?

Answer 2

Acyanotic (L-R shunt)

Question 3

What can cause a PDA?

Answer 3

Low oxygen content
Circulating prostaglandins (PGE2)

Question 4

What mediates PGE2

Answer 4

COX 2 isoform

Question 5

How do you treat a PDA?

Answer 5

Cox 2 inhibitors

• Ibuprofen
• Indomethacin

Question 6

What are the key characteristics of a PDA?

Answer 6

• Continuous murmur
• Poor eating
• Sweating
• Tachycardia
• Tachypnea
• Easily Fatigued

Question 7

What are the characteristics of a persistent ductus arteriosus?

Answer 7

• High pressure in aorta goes into pulmonary trunk

- Can destroy capillary beds in lung

Question 8

Is a ASD acyanotic or cyanotic?

Answer 8

Acyanotic

L to R shunt

Question 9

What is ostium secundum? What is the embryological cause?

Answer 9

A common ASD with a patent foramen ovale

Excessive cell death and resorption of septum primum and inadequate development of septum secundum

Question 10

What type of defect is a probe patent foramen ovale? What is the embryological cause?

Answer 10

ASD

Incomplete adhesion between foramen ovale and septum secundum after birth

Question 11

What type of defect is ostium primum?What is the embryological cause? What is commonly associated with it?

Answer 11

ASD

Failure of the septum primum to fuse with the endocardial cushions

Mitral valve cleft

Question 12

Are ventricular septal defects (VSDs) cyanotic or acyanotic? What is the embryological cause?

Answer 12

Acyanotic
L to R shunt
Did not form the membranous part of the interventricular septum with the heart

Question 13

What is the embryological basis for a AV septal defect?

Answer 13

There is a failure of the endocardial cushions to fuse

Question 14

Is an AV septal defect cyanotic or acyanotic?

Answer 14

Acyanotic

L to R shunt

Question 15

What other features are common with an AV septal defect?

Answer 15

ASD
VSD
Abnormal valve leaflets

Question 16

What population of individuals is at risk for developing an AV septal defect?

Answer 16

Down’s Syndrome

Question 17

What are the two types of AV Septal Defects?

Answer 17

Complete

Partial

Question 18

Describe a complete AV septal defect

Answer 18

Primum ASD that is contiguous with a VSD and common AV valve

Question 19

Describe a partial AV septal defect

Answer 19

Primum ASD with single AC valve annulus with 2 separate valve orifices
Mitral valve cleft

Question 20

“Corrected” Transposition of the Great Vessels. Cyanotic or Acyanotic? What is the embryological mechanism behind this defect?

Answer 20

Rt ventricle is where LV was but is connected to the aorta and LV is connected to pulmonary trunk

Caused by improper septation of the outflow tract and reversed rotation of the heart

Question 21

Is transposition of the great vessels cyanotic or acyanotic? What are characteristic features of the disease? What is the embryological mechanism to describe this defect?

Answer 21

Cyanotic
R to L Shunt

Have the RV attached to the aorta and LV attached to the pulmonary trunk (so you’re pumping deoxygenated blood throughout the body-causing cyanosis)

Caused by improper spiraling of NC cells

Question 22

Is a double outlet right ventricle cyanotic or acyanotic? What are some features of this defect? What is the embryological mechanism for this defect?

Answer 22

Cyanotic (R to L shunt)

The great vessels are receiving blood from RV
VSD also present in most cases

Caused by
Abnormal migration of bulbar ridges during septation
Misalignment of ventricular septum

Question 23

Is truncus arteriosus cyanotic or acyanotic? What are some characteristic features? What is the embryological mechanism for this defect?

Answer 23

Cyanotic (R to L shunt)

Single great vessel
Interventricular septal defect

Absence of bulbar and truncal ridges to form and migrate to midline

Question 24

****Is tetrology of fallot cyanotic or acyanotic? What are some of the features of this defect? What is the embryological mechanism accounting for this defect?

Answer 24

Cyanotic
R to L shunt

Features:
Pulmonary stenosis
Interventricular septal defect
Over-riding aorta
Right ventricular hypertrophy

Caused by:
Abnormal septation of outflow tract

Question 25

Is critical pulmonary stenosis cyanotic or acyanotic? What are the features of this defect?

Answer 25

``` Cyanotic R to L shunt Cusps of pulmonary valves are fused or thickened Decrease in pulmonary blood flow RV hypertrophy ```

Question 26

Is critical aortic stenosis cyanotic or acyanotic? What are some of the features of this defect?

Answer 26

Cyanotic Decrease in systemic blood flow Features - Tachypnea - Poor feeding - Hypoplastic left heart syndrome

Question 27

Is hypoplastic left heart syndrome cyanotic or acyanotic? What are some embryological features of this defect? What is it dependent on?

Answer 27

Cyanotic Decrease in systemic blood flow Features: - Mitral valve stenosis or atresia - Left ventricle is hypoplastic (underdeveloped) - Aortic valve stenosis or atresia - Aortic arch hypoplastic Dependent on PDA and ASD