Congenital Heart Disease 1 Flashcards
What is the prevalence of congenital cardiovascular malformations in USA live-born infants?
5-8 per 1,000
0.5-0.8%
What gender is more likely to have severe congenital heart disease?
Males
True or False: African americans are more likely to have congenital heart disease
False. There is no difference in race, parental age, or marital status
True or False: Maternal diabetes is a risk factor for congenital cardiovascular disease
True. 3x risk
Fetal echo recommended in this subpopulation of patients
True or False: Family history of cardiac defect in a first degree relative (parent or sibling) is a major risk factor
True
For family history of PAD or PFO, this typically isn’t severe enough to warrant screening. It’s typically the more complicated cardiac birth defects that we decide to screen future births and siblings for
What is the prevalence of the following defects? Per 10,000 live births
- VSD
- PDA
- TOF
- ASD
- Coarctation of the aorta
VSD - 15.6 per 10,000 PDA - 5 TOF - 2.6 ASD - 2.35 Coarctation of the aorta - 1.39
What keeps the ductus arteriosus open?
Prostaglandins: a product of the metabolism of arachidonic acid; potent vasoactive agent.
Prostaglandins are produced by the placenta. In utero, ductus is kept open by this exposure.
Site of production is not entirely understood. In addition to the placenta, it is thought to be locally produced at the ductal wall.
Administration of prostaglandin (PGE1) through IV will maintain ductal patency postnatally which can be beneficial to compensate for other congenital heart defects. It can be kept open for as long as you need it to be as long as they are on the IV PGE.
What is a shunt?
A connection between 2 chambers/vessels
What determines the direction of blood flow through a shunt?
Pressure or resistance difference between the 2 chambers
In standard shunt nomenclature, what is a left-to-right shunt?
This is blood flow from a systemic chamber into a pulmonary chamber
Systemic chambers: Pulmonary veins, left atrium, left ventricle, aorta
Pulmonary chambers: Systemic veins, right atrium, right ventricle, pulmonary arteries
The magnitude of a shunt across a PDA is based on what 3 factors?
- Size of PDA
- Relative resistances of the aorta and pulmonary artery
- Pressure differences between the aorta and pulmonary artery
In PDA, what direction shunt is most common?
Left to right, because the pressure and resistance of aorta is greater than the pulmonary resistance or pressure.
What are the symptoms of PDA?
Small PDA is asymptomatic.
Moderate to large PDA have symptoms within the first couple days (especially preterm infants).
You will see symptoms that are consistent with increased pulmonary blood flow and decreased systemic blood flow.
- Difficulty weaning off ventilator
- Pulmonary edema/hemorrhage
- Congestive Heart Failure
- Feeding intolerence (can lead to bowel ischemia - necrotizing enterocolitis which is life threatening)
- Renal insufficiency (not enough blood flow to kidneys)
- Intraventricular hemorrhage or stroke
- Death (Rarely)
Older infants or young children can have specific clinical presentation.
Hoarse cry
History of pneumonias
Failure to thrive
Labored breathing and diaphoresis with activity/feeding
Note that even a large ductus can be asymptomatic in an older child. (subtle exercise intolerance or frequent “infections”/asthma)
What are 5 physical exam findings of a large PDA with left-to-right flow in a neonate?
- Wide pulse pressure (lower diastolic BP because blood typically travels through the aorta during diastole but with PDA it will escape into the pulmonary artery)
- Bounding pulses (palpable palmar pulses)
- Increased work of breathing
- Hyperactive precordium
- Murmur- variable
What murmurs can you hear with PDA?
Classic: Continuous or machinery sounding murmur along the left upper sternal border. Can be associated with a diastolic rumble if the shunt is large. It’s continuous because throughout all parts of the cardiac cycle, the left side is higher pressure so there is always left to right shunt.
If the velocity is low or if the shunt is tiny, there won’t be murmur. (this is most dangerous because you won’t find it)
An accentuated P2 component of the heart sounds if there is associated pulmonary hypertension.
What is A2 and P2?
A2 is aortic valvue closure and P2 is pulmonary valve closure (both make up the S2 heart sound)
What tools do you use to diagnose PDA?
Can often have an idea of what’s going on from history and physical exam. You can confirm with imaging.
Chest radiograph - typically looks normal if the PDA is small. You may see increased pulmonary vascular markings and an enlarged left atrium and left ventricle if the PDA is large.
Echocardiogram can confirm for sure.