Lecture 5: Congenital Heart Defects Flashcards
Acyanotic defects
- ASD
- VSD
- PDA
- PV Stenosis
- Coarctation of aorta
- Aortic stenosis
Cyanotic defects
- Tetralogy of fallot
- Pulmonary atresia
- Tricuspid atresia
- Hypoplastic left heart syndrome
- TGA
- TAPVR
Everything that starts with T + Pulmonary atresia and Hypo
Pulm atresia is not on PANCE
What kind of shunt do ASD, PDA, and VSD make?
Left to right shunt
Oxygenated to deoxygenated.
What do acyanotic diseases eventually result in?
- HF
- Eisenmenger syndrome with exertion
Eisenmenger results in pulmonary arterial hypertension
What are the outflow obstruction congenital heart defects?
- Pulmonary stenosis
- Aortic stenosis
- Coarctation of the aorta
How does HF tend to present in infants?
- Poor feeding/failure to thrive
- pulm congestion/resp distress
- Fluid retention
- Elevated JVP
- Hepatomegaly
ASD S/S
- Fixed, split S2 and pulmonic ejection murmur
- Respiratory infections and failure to thrive in infants
- Prior to age 40: palps, exercise intolerance, dyspnea, fatigue
Symptoms depend on size
split S2 because A looks like its in the splits.
What are the two ASD types and features?
- Ostium secundum (MC), associated with fetal alcohol syndrome.
- Ostium primum, associated with Down’s syndrome as a endocardial cushion defect
Dx of an ASD
- CXR showing R heart dilation and prominent pulmonary vascularity
- TEE showing size and location
- R Heart catheterization showing increased o2 sat in RA and PA.
Tx of an ASD
- Wait and watch for small
- Asymptomatic but large = can wait 1-3 yrs
- Need closure if symptomatic or > 8mm
if adult do sx in RV enlargment, paradoxical embolism and R-L shunt
Sometimes it is better to wait since the heart will be bigger and the patient can tolerate anesthesia better.
Where is more blood pumped into for a VSD?
More blood into lungs and pulmonary artery
Higher risk of pulm HTN, arrhythmias, stroke
Which region typically is responsible for most VSDs?
Membranous, easier to fix and more asymptomatic
What are the 3 types of VSDs?
- Membranous, MC, easiest to fix
- Muscular (lower septum)
- Inlet (Posterior portion beneath the TV)
What is the MC congenital heart defect?
VSD
Image of VSD pathophysiology
S/S of a symptomatic VSD
- Holosystolic murmur in lower left sternal border
- small = aymptomatic w mumur
- mod-large:Poor feeding, respiratory infections, thrill, diastolic rumble in mitral area
- signs of CHF
- Eventually, eisenmenger syndrome will occur
holo because it can be in 3 diff parts of ventricle aka “whole thing”
Best diagnostic imaging for VSD
Echo
CXR unreliable. use MRI if echo does not diagnose.
What will EKG show usually for VSD?
LVH
Management of VSDs
- Small ones close on their own
- Diuretics + higher calorie intake
- Surgery: for larger shunts by age 2 via patch closure ideally, or transcatheter closure
When is surgical closure indicated for VSD?
- > 8mm with symptoms
- Pulmonary HTN
- Aortic insufficiency
- LA/LV dilation
What does the PDA connect?
Pulmonary artery to aorta
When does a PDA normally close?
By week 1
Becoming the ligamentum arteriosum
What are the risk factors for PDA?
- Female
- Preemies
- High altitude births (> 10k ft)
S/S of PDA
- Holosystolic “machine-like” murmur on auscultation pathognomonic
- Differential cyanosis
- Widened PP
- PMI displacement
- Large eventually leads to HF and eisenmenger syndrome
What is differential cyanosis?
Cyanosis/clubbing of the lower extremities, seen in PDA.
Rest of the body is normal.
This + pulmonary HTN is diagnostic.
VIAGOOGLE not slides
EKG finding for PDA
LVH + LAE
Tx of PDA
- Small: monitor
- To close a PDA in a neonate over day 10, use PGE inhibitor
- Symptomatic/large PDA: Digoxin & furosemide
When is surgery indicated for PDA?
Failure of PGE inhibitor, done via surgical ligation
What are the 3 scenarios in which pulmonary stenosis presents congenitally?
- MC: stenosis of the actual valve
- Hypertrophy of the muscle below the valve
- Hypertrophy of the muscle above the valve
Pathognomic finding for pulmonary stenosis
Schistocytes on CBC due to microangiopathic hemolytic anemia
In severe pulmonary stenosis at birth, what can be given to keep the neonate oxygenated?
PGE to keep their PDA open as an alternative pathway
Severe PS will cause a R to L shunt via PFO at birth if obstructed
S/S of pulmonary stenosis
- Systolic ejection murmur that increases with inspiration
- opening click louder with expiration
- RV lift of palpation of precordium
What might EKG and CXR show for pulmonary stenosis?
- EKG: none to mild RVH
- CXR: Dilation of main pulmonary artery and left PA
What is the surgery for pulmonary stenosis?
Percutaneous balloon valvuloplasty
What is coarctation of the aorta?
Narrowing of the aortic arch (usually proximal descending), backing blood flow up to the left ventricle.
Although coarctation of the aorta is more common in males, what condition in females makes it more likely?
Turner syndrome
What is the leading cause of heart failure in neonates?
Coarc +/- VSD, ASD, or other cardiac abnormalities
Why does BP increase in upper extremities for coarc but decreased BP in lower extremities? What is the danger of poor perfusion in the lower half of the body?
- Blood flow increases prior to the narrowing.
- Lower BP in lower extremities results in kidney hypoperfusion, ultimately causing secondary HTN.
Kidney hypoperfusion = RAAS activation = secondary HTN
What is preductal coarctation MC associated with?
- Turner syndrome
- PDA
- Presents as postductal until it worsens severely.
MC in infancy
What structure is the marker for postductal coarctation and its common S/S?
- Ligamentum arteriosum
- Higher BP upstream of aorta, lower BP downstream
- Often presents in adulthood.
What are the two biggest risks from coarctation increasing upper body BP?
- Berry aneurysm rupture in head
- Aortic dissection
How does coarctation of the aorta in an infant present?
- Diamond shaped systolic
- High-pitched crescendo murmur for diastolic
- Lower extremity cyanosis
- Absent/delayed femoral pulses, esp on the R side
- Failure to thrive
- Much higher BP in upper arms than lower body.
Coarc will not present on the left!!
S/S of coarctation of the aorta in an adult
- Secondary HTN in upper extremities, lower in lower extremities
- CP, cold extremities, claudication on exertion
- PMI palpable and sustained
- Pulsations in intercostal spaces
- Delayed/weak femoral pulses (check R!)
CXR finding for coarctation of the aorta
3-sign rib notching
How do you tx coarctation of the aorta?
- PGE to increase lower extremity flow
- Surgery via anastomosis
- Balloon angioplasty with possible stent
What precaution should a child have if they have coarctation of their aorta?
Exercise testing is mandatory prior to participating in athletic activities
What are the 3 types of aortic stenosis?
- Valvular (75%)
- Subvalvular (23%)
- Supravalvular (2%)
MC in males
What murmur is pathognomonic for Aortic Stenosis?
Crescendo-Decrescendo holosystolic murmur best heard at the upper right sternal border
Radiating to the carotids :)
How do you treat standard valvular AS?
Percutaneous balloon valvuloplasty
Surgery in other types or very high resting gradient
What happens as AS progresses in a child?
- Reduced exercise capacity
- Predisposed to ventricular dysrhythmias
- Avoid all isometric exercise
What level of deoxy Hgb is likely to have cyanosis?
3g/dl, which is usuall 80-85% spo2
What test differentiates cardiac and non cardiac causes of cyanosis?
Hyperoxia test
Greater than PaO2 of 250 = no structural cyanotic disease
Give neonate 100% O2
What are the 5 T’s of cyanotic heart disease?
- Truncus Arteriosus
- TGA
- Tricuspid atresia
- Tetralogy of Fallot
- TAPVR
Tetralogy of Fallot components
- Pulmonary stenosis
- RVH
- Overriding Aorta
- VSD
PROVe
What is the pathogonomic finding for tetralogy of fallot on CXR?
Boot shaped heart
What is a tet spell?
- Hypercyanotic episode
- Anything that decreased SVR will leads to a worse R to L shunt
- Bluish skin seen during crying/feeding
Management of a tet spell
- Keep them calm
- Give O2
- IVF
- Meds to improve pulmonary blood flow
- Squat or flex knees to increase SVR
- Morphine (Decrease agitation and RVOT obstruction)
- Bicarbonate (metabolic acidosis causes pulmonary vasoconstriction)
- Phenylpephrine (increases SVR)
- BB (Decrease RVOT obstruction)
Increasing SVR will increase LV pressure, so the shunt will reverse back to L to R.
How soon do ToF babies need surgery?
Prior to age 2, they need open heart surgery for a good prognosis
What is TGA?
- Aorta coming off RV
- PA coming off LV
Forms two separate circuits, so blood will never be oxygenated
Parallel circulation occurs.
What are the two types of TGA?
- d-TGA: dextro/complete TGA where aorta is on the right.
- l-TGA: levo/congenitally conrrected TGA, aorta on left, ventricles and valves switched instead.
d-TGA is lethal, L-TGA is fine
What are the two MC CCHD?
Critical congenital heart defect
- ToF
- d-TGA (males)
What connection must be made in order for d-TGA to be viable?
ASD or PFO to allow mixing of blood.
Risk factors for TGA
- Diabetes
- Rubella
- Poor nutrition
- Alcohol
- > 40y
Classic triad of CXR for d-TGA
- Egg on a string (heart)
- Lung congestion
- Cardiomegaly
Initial tx for d-TGA
PGE to keep PDA open
Surgery for d-TGA
- Balloon atrial septostomy
- Surgically switch great vessels
What is hypoplastic left heart syndrome?
- Poorly developed LV and ascending aorta
- Valves may be narrow or absent
- Ultimately leading to left sided HF and cardiogenic shock
CANNOT DO ANYTHING VIGOROUS
What is required for an infant with hypoplastic left heart syndrome to survive?
An ASD or PDA, since their left side cannot sustain life.
Initial tx for practically all cyanotic defects
PGE
Surgical protocol for HLHS
- Norwood (new aorta to RV and tube to RA) (1-2 wk old)
- Bidirectional Glenn (PA & SVC connection) (4-6 months)
- Fontan (PA & IVC connection) (2y)
3 stage surgery
What are the 6 innocent murmurs of childhood?
- Newborn murmur
- Peripheral pulmonary artery stenosis (PPS)
- Still’s murmur (MC)
- Pulmonary ejection murmur
- Venous hum
- Neck/supraclavicular bruit
How does Still’s murmur sound?
- Loud when supine, gone when inspiring or sitting
- Loud with anemia and fever