MHD: Congenital Heart Disease Flashcards Preview

MHD/Pharm Block 4 > MHD: Congenital Heart Disease > Flashcards

Flashcards in MHD: Congenital Heart Disease Deck (28):
1

What is meant by "the complex" in congenital heart diseases?

When a group of abnormalities tend to be associated and contribute together to altered economy of the heart

2

What is a shunt?

A transfer of blood from one side of the circulation to the other through an abnormal pathway (Left to right, right to left)

3

What is the major shunt associated with the atria?

Atrial septal defect (ASD)

4

What is the major shunt associated with the ventricles?

Ventricular septal defect (VSD)

5

What is the major shunt associated with the ducts?

Patent ductus arteriosus (PDA)

6

What are the types of atrial septal defect?

Fossa ovalis (Secundum type)
Ostium primum type
Sinus venosus (proximal type)
Coronary sinus type

7

Describe the blood flow through an atrial septal defect

Left to right shunt forms because the pressure in the left atrium is slightly higher than the right atrium and the right ventricle has a much larger compliance.
Result: volume hypertrophy of RA and RV, increased pulmonary flow

8

Do ASDs typically cause cyanosis and hypoxemia?

No. L to R shunt moves some oxygenated blood back to pulmonary, but does not typically reverse.

9

What is the most common type of VSD?

Subaortic: defect located just beneath the aortic valve through the membranous septum

10

Describe the blood flow through a ventricular septal defect

Left to right shunt leads to volume hypertrophy of the left atrium, left ventricle, right ventricle and enlargement of the pulmonic orifice

11

What is the natural history of VSDs?

Small defects can be asymptomatic, resolve in first few years of life.
VSDs increase risk for infective endocarditis

12

What is Eisenmenger syndrome?

Reversal of shunt direction due to changes in vascular resistance
Ex: as defect progresses, pulmonary pressure can raise above the left sided pressure, leading to R to L shunting

13

Describe the blood flow through a patent ductus arteriosus

Left to right shunt through the ductus arteriosus leads to volume hypertrophy of the LA and LV

14

Which congenital defects increase pulmonary flow?

L to R shunts
ASD, VSD, PDA

15

What are the reasons for the development of pulmonary hypertension in congenital heart defects?

Flow beyond the distensibility of the lung vasculature
Vasoconstriction of pulmonary vascular bed
Secondary pathologic changes in lung

16

Which shunts are most likely to involve pulmonary hypertension

VSD > PDA > ASD

17

Congenital pulmonary stenosis results in hypertrophy of what chamber?

Right ventricle

18

Congenital aortic stenosis results in hypertrophy of what chamber?

Left ventricle

19

What are the two types of supravalvular aortic stenosis?

Subaortic stenosis: involves fibroelastic tissue
Muscular: hypertrophic cardiomyopathy

20

What is coarctation of the aorta?

Narrowing of the transverse aortic arch

21

What is tetralogy of fallot?

A developmental defect leading to 4 anomalies:
1)Infundibular pulmonary stenosis
2)Right ventricular hypertrophy
3)VSD
4)Overriding aorta (receives blood from RV and LV)

22

What is the infundibulum?

The outflow tract of the right ventricle

23

What is the characteristic shape of the VSD in tetralogy of fallot?

U shaped

24

What are the two types of tetralogy of fallot?

Cyanotic (more common)
Acyanotic

25

Describe the effects of cyanotic tetralogy of fallot

Pressure hypertrophy of RA and RV due to pulmonary obstruction. LA and LV are typically smaller than normal.
Prominent R to L shunt leads to cyanosis

26

Describe the effects of acyanotic tetrology of fallot

L to R shunt at ventricles, so no cyanosis
Hypertrophy of RV, RA, LA and LV

27

What happens in Transposition of the Great Arteries?

Aorta originating from RV, pulmonary artery from LV
2 separate circuits in parallel as opposed to the normal in-series arrangement, oxygenation of systemic blood does not occur

28

Why doesn't TGA cause death during fetal development or early after birth?

The physiologic shunts (foramen ovale and ductus arteriosus) allow mixing between the two circuits, so some oxygenated blood is able to reach system.

These must remain open for the defect to be compatible with life.