8/18- Congenital Heart Disease Flashcards Preview

_MS2 Cardio > 8/18- Congenital Heart Disease > Flashcards

Flashcards in 8/18- Congenital Heart Disease Deck (45):
1

A child with cyanotic heart disease most likely has a heart defect that shunts?

A. Right to left

B. Left to right

A child with cyanotic heart disease most likely has a heart defect that shunts?

A. Right to left

B. Left to right

2

Which of the following patients is most likely to have irreversible pulmonary hypertension?

A. A 10 yo with tetrology of Fallot

B. A 1 yo with muscular VSD

C. A 10 yo with truncus arteriosus

D. A 10 yo with ASD

Which of the following patients is most likely to have irreversible pulmonary hypertension?

A. A 10 yo with tetrology of Fallot

B. A 1 yo with muscular VSD

C. A 10 yo with truncus arteriosus

D. A 10 yo with ASD

3

Epidemiology of Congenital Heart Disease

- Child

- Adult

Child

- Most common heart disease

- May become symptomatic with transitional circulation

- Most repaired in childhood--but sequelae

Adult

- >85% childhood CHD become adults

- More adults with CHD than children (repaired lesions)

- Most cardiologosits trained in CHD are pediatric...

Short and long term sequelae require care

4

What is the definition of congenital heart disease?

Non-heart structures affected?

- Structural malformations

- Present at birth

- Result from abnormal embryogenesis (3-8 wks gestation)

Associated extracardiac anomalies: 16-39%

5

What is a shunt (basic def)?

Abnormal communication between systemic and pulmonary circulation

6

In a shunt, the direction and amount of blood flow is determined by what factors?

- Size of defect

- Vascular resistance

- Pressure gradient

- Distensibility of chambers

7

Clinical consequences of a shunt?

- Increased blood flow in one circulation; decreased in the other

- Decreased oxygen in systemic circulation

8

What is cyanosis (def)?

Arterial O2 desaturation with > 3-5 gm/dL of unsaturated Hb

- Blue discoloration of nailbeds and mucus membranes

- Clubbing: convexity of nailbed +/- expansion of distal end of digit

9

Functional classifications of shunts? Examples?

1. Left to right shunt (systemic -> pulmonary)

- ASD

- VSD

- PDA

2. Right to left shunt (pulmonary -> systemic)

- Tetrology of Fallot

- TV atresia

- Truncus arteriosus

- TAPVC

- TGA

- HLHS

3. Obstructions

- Coarction of aorta

- Valve stenosis or atresia

- Subvalve or supravalve stenosis

10

Functional consequences due to changes in what factors?

- Oxygen saturation

- Blood volume

- Blood pressure

 Ultimate effects on tissue perfusion

11

Evaluation of pts with CHD

Physical exam:

- Murmurs, thrills, heart sounds, pulses/BP/ cyanosis (upper and lower extremity differences)

CXR

ECG

Labs:

- Arterial blood gas

- Lactate

Diagnostic

- Echocardiogram

- Cardiac cath

- Cardiac MRI

- CT angiography

12

What are the left to right shunts?

- ASD

- VSD

- PDA

13

Characteristics of left to right shunts?

- Increased pulmonary blood flow

- Decreased systemic CO

- No direct effect on oxygenation

-> Pulmonary edema

-> Congestive Heart Failure

14

What are the 3 major types of atrial septal defects? What percentage of all CHD do these comprise?

ASD are 10% of all congenital heart defects 3 major types:

1. Secundum

2. Primum

3. Sinus venosus 

15

Which ASD is the most common?

Secundum (90%)

16

What causes secundum ASD/where does it occur?

Valve of foramen ovale (septum primum) not well developed

- usually an isolated lesion

17

What are the consequences/effects of ASD?

- Increased RA and RV preload -> dilation

- Increased pulmonary bloodflow (but not pressure)

- High RV compliance

- Slow increase in PA pressure

Usually asymptomatic until ~age 30

- Pulmonary HTN

- RV heart failure

Large ASD:

- Early heart failure 

18

Treatment of ASD?

Repair

- ASD closure device or patch

19

VSDs are responsible for __% of all CHDs

VSDs are responsible for 40% of all CHDs

20

What are the 3 major types of VSD? Which is the most common?

1. Membranous (perimembranous)

2. Infundibular (conal septal)

3. Muscular Peri/Membranous is the most common (90%)

21

What is this?

Membranous ventricular septum (light shining through)

22

What is this? 

Perimembranous VSD

23

What are the consequences/effects of VSD?

- Increased pulmonary blood flow AND pressure

- Increased LV preload/volume

- Decreased CO

-> Pulmonary edema

-> Congestive Heart Failure (left sided! volume load on left side)

Size affects symptoms!

Symptom onset often with drop in neonatal pulmonary vascular resistance 

24

Spontaneous closure of perimembranous VSD may be due to what? Muscular VSD?

Perimembranous VSD: adherence of TV

Muscular VSD: growth of heart muscle

25

What is shown here on the left? right? 

Left: perimembranous VSD (clsoed by TV adherence)

Right: muscular VSD (closed by heart muscle growth)

26

How is VSD treated? When to treat?

- May close spontaneously

- Usually patch closure if no spontaneous closure

When considering repair, think of:

- Likelihood of spontaneous closure (usually before 5 yo)

- Severity of clinical Sx (may correlate with size of defect)

- Risk of irreversible pulmonary HTN (unusual before 2 yo)

27

What are the long term sequelae for patching a VSD?

- Infective endocarditis (prosthetic patch)

- Patch dehiscence

- Arrhythmias

28

What is the "dreaded" complication for a left to right shunting lesion?

Pulmonary HTN and shunt reversal

- Uncontrolled, persistent increased pulmonary pressure/resistance will reverse the direction of a left to right shunt

-> Late onset cyanosis

Irreversible pulmonary HTN is the dreaded complication of a L to R shunt

- Once it develops, repair of defect is not indicated 

29

What are CHDs of Right to Left shunt?

How may they be divided?

Decreased pulmonary bloodflow (more common):

- Tetralogy of Fallot (TOF)

- TV atresia

Increased pulmonary bloodflow:

- Truncus arteriosus

- TAPVC

- TGA

- HLHS

30

Characteristics of right to left shunts with decreased pulmonary blood flow?

(Decreased pulmonary bloodflow)

Associated with:

- R sided obstruction distal to shunt (e.g decreased pulmonary outflow tract), OR

- Elevated pulmonary pressure

Desaturated venous blood enters systemic circulation

- > cyanotic congenital heart disease

-> poor tissue oxygenation

31

What is the Tetaralogy of Fallot (TOF)?

Malaligned outflow tract septum resulting in:

- SubPA (RVOT) stenosis

- VSD

- Aortic over-ride of VSD

- RV hypertrophy

Stenosis severity determines direction of magnitude and shunt

32

What is this? 

Tetralogy of Fallot 

33

Physiology (consequences) of TOF?

- Increased RV preload/volume

- Increased afterload/pressure -> RV dilated and hypertrophied (more blood going into aorta; more returning to right A/V -> R sided failure)

- PA is small (hypoblastic)

- Aorta s dilated

34

What are the systemic consequences of TOF?

Poor tissue oxygenation

- Hypoxemia and polycythemia

- Cyanosis that worsens with exercise

- Clubbing after 3 mo of age

Paroxysmal hypoxia

- RVOT spasms

- (TET spells)

35

How is TOF treated?

Surgical repair: as early as feasible

- Improve tissue perfusion

- Decrease risk of post-operative arrhythmias

Common follow-up = valve replacement before pulmonary regurg causes permanent problems with volume load on _ventricle

36

What is the most common form of cyanotic congenital heard disease?

Tetralogy of Fallot (TOF)

37

TOF is responsible for __% of congenital heart disease?

TOF is responsible for 5% of congenital heart disease?

38

What is the current survival rate of TOF?

> 75-80% 30 yrs

TOF is one of the most common anomalies seen in adult with congenital heart disease

39

What is TV atresia? Characteristics? Consequences?

CHD that involves a right to left shunt and decreased pulmonary blood flow

- Obligate RA -> LA shunt at atrial septum (no communication between R heart and pulmonary artery?)

- Increased LA and LV volume

- Pulmonary blood flow is dependent on VSD usually decreased

-> cyanotic CHD 

40

What is truncus arteriosus? Characteristics? Consequences?

CHD that involves a right to left shunt and increased pulmonary blood flow

- Due to failure of embryonic truncus and usually outflow tract of heart to develop a septum

- Single great artery gives rise to aorta, pulmonary, and coronary arteries

- Single semilunar (truncal) valve that may be stenotic or regurgitant

Consequences:

- Variably increased pulmonary bloodflow

- High risk for pulmonary HTN

-> cyanotic CHD) 

41

What is TAPVC?

Total anomalous pulmonary venous connection

- Obligate right -> left shunt at atrial septum

- Pulmonary veins don't connect to LA

May connect to various sites:

- Most common = innominate vein

Consequences:

- Increased RA and RV volume

- Increased pulmonary bloodflow -> cyanotic CHD 

42

Most obstructive lesions are ___

Most obstructive lesions are valvular

43

Physiology (characteristics) of obstructive lesions?

- High pressure proximal to obstruction

- Decreased bloodflow distal to obstruction

44

What is shown here? 

Obstructive lesion: aortic valve stenosis

45

Treatment for obstructive lesions?

- Balloon repair

- Valve replacement