8/18- Congenital Heart Disease Flashcards
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
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
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*
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%
What is a shunt (basic def)?
Abnormal communication between systemic and pulmonary circulation
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
Clinical consequences of a shunt?
- Increased blood flow in one circulation; decreased in the other
- Decreased oxygen in systemic circulation
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
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
Functional consequences due to changes in what factors?
- Oxygen saturation
- Blood volume
- Blood pressure
- Ultimate effects on tissue perfusion*
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
What are the left to right shunts?
- ASD
- VSD
- PDA
Characteristics of left to right shunts?
- Increased pulmonary blood flow
- Decreased systemic CO
- No direct effect on oxygenation
- > Pulmonary edema
- > Congestive Heart Failure
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:
- Secundum
- Primum
- Sinus venosus
Which ASD is the most common?
Secundum (90%)
What causes secundum ASD/where does it occur?
Valve of foramen ovale (septum primum) not well developed
- usually an isolated lesion
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
Treatment of ASD?
Repair
- ASD closure device or patch
VSDs are responsible for __% of all CHDs
VSDs are responsible for 40% of all CHDs
What are the 3 major types of VSD? Which is the most common?
- Membranous (perimembranous)
- Infundibular (conal septal)
- Muscular Peri/Membranous is the most common (90%)
What is this?
Membranous ventricular septum (light shining through)
What is this?
Perimembranous VSD
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
Spontaneous closure of perimembranous VSD may be due to what? Muscular VSD?
Perimembranous VSD: adherence of TV
Muscular VSD: growth of heart muscle
What is shown here on the left? right?
Left: perimembranous VSD (clsoed by TV adherence)
Right: muscular VSD (closed by heart muscle growth)
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)
What are the long term sequelae for patching a VSD?
- Infective endocarditis (prosthetic patch)
- Patch dehiscence
- Arrhythmias
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
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
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
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
What is this?
Tetralogy of Fallot
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
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)
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
What is the most common form of cyanotic congenital heard disease?
Tetralogy of Fallot (TOF)
TOF is responsible for __% of congenital heart disease?
TOF is responsible for 5% of congenital heart disease?
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
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
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)
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
Most obstructive lesions are ___
Most obstructive lesions are valvular
Physiology (characteristics) of obstructive lesions?
- High pressure proximal to obstruction
- Decreased bloodflow distal to obstruction
What is shown here?
Obstructive lesion: aortic valve stenosis
Treatment for obstructive lesions?
- Balloon repair
- Valve replacement
