Clin Med - Congenital Heart Disease Flashcards
What is patent ductus arteriosus? (PDA)
Blood flowing from aorta to pulmonary artery.
What keeps PDA open?
Prostaglandins
What closes PDA?
A prostaglandin inhibitor (indomethacin)
What triggers the closure of PDA?
Highly oxygenated blood.
Who is at risk for non-closure?
High altitude births and premature babies at risk for non-closure.
When do normal PDAs close?
Small PDA normal for 24-48h after birth
- 20% closed @ 24h
- 80% closed @ 48h
- 100% closed @ 96h
What neonates are at greater risk?
neonates whose mother contracted Rubella in 1st Trimester are at greater risk.
PDA in adults
- Very Rare
- Typically Asymptomatic till middle age (most are small and well tolerated)
- Again, think about Right Sided Congestive Heart Failure
PDA Physical Exam & Murmur
- Widened Pulse Pressure
- Bounding Peripheral Pulses
- Continuous, Machine-like murmur over Pulmonic area (Left Upper Sternal Border)
- -A Thrill is COMMON
When should you refer PDA?
All adults with a PDA should be referred to a cardiologist.
What is VSD?
Ventricular Septal Defect - the MOST COMMON congenital heart defect
What kind of shunting is VSD?
Left to right shunt.
What co-morbidity is VSD associated with?
Down’s Syndrome
Size of VSD
Small defects are louder. The smaller the VSD, the louder the murmur.
Small VSDs are typically asymptomatic.
Term for acyanotic turning cyanotic
Eisenmenger physiology
What is Eisenmenger physiology?
Often associated with Large VSD and Long standing VSD and ASD (even PDA).
Pulmonary HTN causes the pulmonary resistance to exceed that of the systemic resistance and left-to-right shunts are reversed causing cyanosis in typically acyanotic defects
Ventricular Septal Defect : Murmur
- Classic Murmur: Pan/Holo systolic, harsh, vibratory murmur at Left Lower Sternal Border (LLSB)
- Increases with squatting and hand grip.
Ventricular Septal Defect : Imagining
ECHO IS DIAGNOSTIC
Ventricular Septal Defect : Treatment
- Control the Congestive Heart Failure with diuretics and digoxin
- Surgery if infant has growth failure, medications not working, or impending pulmonary hypertension
VSD: When to Refer
All patients with a VSD should be referred to a cardiologist to determine need for long term follow up and surgical intervention
Key to Coarctation of Aorta
PULSES!! You HAVE to palpate the brachial and femoral pulses at each Well Child Check.
*Co. of A. will have weak femoral pulses
When should you begin taking a child’s BP?
At and after 3y.o.
Co. of A. should be suspected in young patients with elevated blood pressure
Co. of A. : Physical Exam Findings
- BP of Upper extremities is GREATER than that of the lower extremities. (Lower BP can be normal or low)
- Weak Femoral Pulse
- Look for signs of Left Sided Congestive Heart Failure (rales/crackles, cough, fatigue)
What are the 4 components to tetralogy of fallot?
4 components
- Overriding Aorta
- Pulmonary Stenosis
- Ventricular Septal Defect (VSD)
- Right Ventricular Hypertrophy
Significance of tetralogy of fallot
Most COMMON CYANOTIC CONGENITAL HEART DEFECT
Right-to-Left Shunt
X-ray findings tetralogy of fallot
“Boot-Shaped” heart
Tetralogy of Fallot Hx
- H/o Blue Spells (Tet Spells) & -Dyspnea
- Crying
- Feeding
- Relieved by assuming a squatting position
When to refer a murmur to pediatric cardiologist:
- Greater than Level III
- Diastolic (NEVER GOOD)
- Worsens with Standing
What kind of ECHO?
TEE vs TTE
TEE: looks a the back of the heart, so mitral valve disease and endocarditis
What moms are more likely to have child with congenital heart disease?
Gestational Diabetic Moms
When would you not want to give indomethacin?
Transposition of Great Vessels - you want the PDA open.
What type of shunting is atrial septal defect (ASD)?
Left to Right Shunt due to greater pressure gradient from the system circulation on the Left Side.
Atrial Septal Defect – Children
ASD will typically closes spontaneously during the first year of life.
- Typically asymptomatic
- May have mild fatigue
- Frequent Respiratory Infections
Symptomatic ASD
Requires surgical correction.
- Evidence of Right Ventricular Hypertrophy
- Signs of Right Sided Congestive Heart Failure (CHF)
- Exercise intolerance (easily fatigued)
Atrial Septal Defect - Adults
- In 25% of adults, the foramen ovale remains patent.
- Can cause paradoxic emboli and subsequently cerebrovasular events (consider this in your deferential when a pt is <55 and has had a stroke)
- Typically asymptomatic till their 30s or 40s [be mindful of signs of Right Sided Congestive Heart Failure (CHF) due to Pulmonary Hypertension (HTN)]
- Symptomatic = Surgical Correction
ASD Diagnostic Heart sounds & Murmur
-Wide Fixed Split S2
-Systolic ejection murmur in pulmonic area (Left Upper Sternal Border)
-Mid-Diastolic Rumble at the Lower Left Sternal Border
(due to added flow over tricuspid valve)
ASD Labs and Imaging
- EKG could show Right Ventricular Hypertrophy
- ECHO IS DIAGNOSTIC and will reveal the left-to-right shunt of oxygenated blood btw atria as well as, Right Ventricular Hypertrophy (RVH) and Right sided volume overload *get TransThoracic Echocardiagram (TTE)
ASD Treatment
Unless very small, ASD’s should undergo surgical repair.
Surgical Repair is an absolute if there are any signs of Right Sided over load.
- Pulmonary HTN
- Exercise Intolerance
- Right Ventricular Hypertrophy (RVH)
- Pedal Edema due to Congestive Heart Failure (CHF)
ASD When to Refer?
- At initial discovery on TTE, to investigate any other structural abnormalities of the heart.
- Symptomatic patients
- Pt <55 y.o. with an apparent paradoxic embolic event and an ASD
Fetal circulation
- Umbilical VV drains high oxygen blood via ductus venous to IVC.
- The IVC drains to RA –> LA via foramen ovale.
- The SVC drains low oxygen blood to the RA, making the RA mixed oxygen blood.
- RA –> RV –> pulmonary trunk –> lungs, but some of the blood is shunted via ductus arteriosus to the aorta.
- Blood in the aorta mixes with blood from the LV and goes to internal iliac AA and tissues.
- The umbilical AA sends blood back to the placenta.
Neonate circulation
Circulation resembles that of an adult after the baby is born.
- IVC –> RA –> RV –> pulmonary trunk [ductus arteriosus is no longer present] –> lungs
- lungs –> pulmonary veins –> LA –> LV –> aorta –> tissues