Cardiovascular

Question 1

Tetralogy of Fallot defects

Answer 1

VSD

Overriding aortic arch

Pulmonary stenosis/obstruction

Right ventricular hypertrophy

Question 2

Tetralogy of Fallot embryonic cause

Answer 2

Incomplete rotation of conotruncus—leads to malalignment of conal and ventricular septum

Question 3

Five T’s of cyanotic heart disease

Answer 3

Tricuspid atresia

Truncus

Transposition

Tetralogy of Fallot

TAPVR

Question 4

Two genes responsible for cardiac left-right differentiation

Answer 4

Shh

Pitx2c

Question 5

Vascular defects that present as congestive heart failure (include other findings with each)

Answer 5

1. AVM—liver (hepatomegaly)
2. AVM—cerebral (diminished pulses, pulmonary edema—like PDA but “steal” is up carotid)
3. Vein of Galen aneurysm (cranial bruit/bounding carotid, irritability/seizures, high RA PO2 from highly oxygenated blood shunting thru aneurysm, DIC)

Question 6

Gene responsible for RVOT development

Answer 6

Tbx1

Question 7

Two cardiac abnormalities highly associated with 22q11

Answer 7

Tetralogy of Fallot

Interrupted aortic arch type B (most common type overall, 60% have 22q11 deletion)

(type B is after left carotid artery (before left subclavian))

Question 8

Two things associated with supravalvar pulmonic stenosis

Answer 8

1. Williams syndrome
2. Congenital rubella

Question 9

Milronone mechanism and indications

Answer 9

1. Phosphodiesterase 3 inhibitor—increased cAMP
2. Improved ventricular function
3. Decreased peripheral vascular resistance

Indications: RV dysfunction, improving function in cardiac patients coming off bypass (especially if need decreased SVR)

Question 10

What is the Delta wave and what’s it associated with?

Answer 10

Preexcitation of ventricles (a wave preceding the R)

(Preexcitation is via accessory pathway, causes WPW)

Question 11

Antiarrhythmic drug classes and where they work on phases

Answer 11

I: active depolarization (Na block eg procainamide, lidocaine)

II and III: sustained depolarization phase (beta- and K-block, respectively eg propranolol, amiodarone)

IV: repolarization (Ca-block)

*Do not use Ca-channel blockers (verapimil) in neonates

Question 12

Associations with Ebsteins anomaly

Answer 12

Lithium

Wolff-Parkinson-White and SVT (or RBB–think things that may be affected by a displaced node)

Very enlarged right heart on CXR

Question 13

Starling forces

Answer 13

Hydrostatic: Pressure fluid (ie solvent) exerts outward from capillaries

Oncotic: Pressure solutes exert that pulls fluid into capillaries

Question 14

Physiologic factors that close ductus arteriosus

Answer 14

1) increased PaO2
2) decreased prostaglandins (PGE2)

(Both these occur 2-2 sudden lung inflation at birth)

Question 15

Mechanism of action in PDA closure for indomethacin or ibuprofen

Answer 15

Prostaglandin synthesis inhibition by cyclooxygenase enzyme (COX) inhibition (binds so arachidonic acid cannot)

Success rate equal (75%) between two medications

Question 16

How do glucocorticoids impact ductus arteriosus closure

Answer 16

Potentiate its sensitivity to oxygen (which promotes closure)

Lack of maternal betamethasone is a risk factor for PDA

Question 17

Name the three pathways that affect pulmonary vasoregulation

Answer 17

1. Endothelin (think bosentan AKA Remodulin, endothelin antagonist)
2. Nitric oxide (think iNO, sildenafil)
3. Prostacyclin (think milrinone, epoprostenol AKA Flolan)

(NEJM.org)

Question 18

What is the end effect of bosentan?

Answer 18

Endothelin receptor antagonist, preventing endothelin-receptor complex from causing endothelial constriction and proliferation

Question 19

What is the mechanism of action of sildenafil?

Answer 19

Phosphodiesterase-5-inhibitor

Prevents breakdown of vasodilatory cGMP (nitric oxide pathway)

Question 20

Mechanism of action of milrinone

Answer 20

Phosphodiesterase-3 inhibitor, prevents cAMP breakdown (prostacyclin pathway)

1. Pulmonary vasodilation
2. Reduces afterload (arterial relaxation)
3. Improves myocardial [ventricular] function

Question 21

What effects do corticosteroids have in relation to pulmonary hypertension

Answer 21

1. Reduce reactive oxygen species
2. Increase cGMP synthesis
3. Reduce cGMP metabolism
   * Net pulmonary vasodilation (via nitric oxide pathway)*

Question 22

What characteristic of the blood vessels most significantly impacts blood flow?

Answer 22

Vessel diameter (AKA radius)

Think of Poiseuille’s Law–inverse, where because:

Q=P/R

Q=P x (πr⁴ / 8nL)

Question 23

What are the main substrates of the 1) fetal and 2) adult myocardium?

Answer 23

1. Fetal - glucose and lactate
2. Adult - fatty acids

Question 24

Characteristic cardiac findings in glycogen storage diseases

Answer 24

Short PR interval

Biventricular hypertrophy

Question 25

Conotruncal lesions should make you think of what genetic syndrome?

Answer 25

22q11, AKA DiGeorge

Question 26

Mechanisms of hydrocortisone on increasing blood pressure (four groups of action)

Answer 26

1. Inhibits nitric oxide synthase (NOS) and prostaglandin release - inhibits vasodilation 2. Increases Ca⁺⁺ concentration - contractility 3. Upregulates adrenergic receptors and decreases catecholamine metabolism - vasoconstriction and contractility 4. Upregulates angiotensin-II receptors - vasoconstriction

Question 27

Cardiac defects associated with elfin facies, open mouth, transient hypercalcemia

Answer 27

Supravalvar aortic OR pulmonic stenosis (Rubella is also associated with supravalvar pulmonic stenosis)

Question 28

Cardiac defects associated with Rubella

Answer 28

Patent ductus arteriosus (PDA) Supravalvar pulmonic stenosis

Question 29

Oxygenation index equation

Answer 29

OI= (what you've put in) / (what you get out) (MAPxFiO2) / PaO2 *OI\>40 is considered the threshold for ECMO*

Question 30

How does PCO2 influence pulmonary vs cerebral blood flow

Answer 30

A low PCO2 vaso**dilates** pulmonary vasculature A low PCO2 vaso**constricts** cerebral vasculature *Reason that patients with head injuries used to be hyperventilated, and patients with PPHN would be overventilated*

Question 31

What percentage of infants with BPD develop pulmonary hypertension

Answer 31

1/3 ## Footnote *Reason to do screening echocardiography, and theoretically consider cardiac catheterization*

Question 32

The congenital heart defect variants known for a reverse saturation differential

Answer 32

dTGA with aortic coarctation dTGA with pulmonary hypertension

Question 33

Two ECG abnormalities seen in Pompe disease

Answer 33

Short PR interval Bilateral ventricular hypertrophy *Can also have preexcitation (all from their hypertrophic cardiomyopathy)*

Question 34

Hydrocortisone ________ catecholamine metabolism

Answer 34

decreases * So they "stick around" longer* * It also decreases NOS expression and prostaglandin action*

Question 35

The first- and second-line agents for fetal SVT

Answer 35

Digoxin and amiodarone ## Footnote *Digoxin first-line mainly 2-2 safety profile, while amiodarone's 90% effective for AV reentry*

Question 36

Normal QRS axis for term neonates

Answer 36

+55 to +200 ## Footnote *Remember it's right-axis deviation that's normal*

Question 37

Frequency of chromosomal abnormalities in fetus with congenital heart defects

Answer 37

1 in 8 *fetuses* *Most commonly the Trisomies (21, 18 and 13) or DiGeorge*

Question 38

The most common brain abnormalities in CHD

Answer 38

White mattery injury and infarction ## Footnote *Including on preoperative MRI*

Question 39

Four genes associated with HLHS

Answer 39

NKX2-5 GJA1 NOTCH1 HAND1 *Sibling's likelihood of ANY CHD with prior infant with HLHS is 22% (8% for HLHS in particular)*

Question 40

Most commonly affected gene in Long QT Syndrome (LQTS)

Answer 40

KCNQ1 ## Footnote *Both LQTS and KCNQ1 have a _**Q\_**_*

Question 41

The typical timeframe for symptomatic hypertrophic cardiomyopathy 2-2 maternal diabetes to resolve

Answer 41

1 month ## Footnote *NeoReviews*

Question 42

The amount of desaturated hemoglobin needed for cyanosis

Answer 42

3-5g/dL ## Footnote *Since it's an absolute amount, that's why the higher your Hb the less desaturation's needed to appear cyanotic (e.g. 80% saturated with a Hb 15 vs. 70% when Hb 10)*

Question 43

The risk of CCHD in siblings of a person with HLHS (hypoplastic left heart syndrome)

Answer 43

22% for *any* CHD, 8% for HLHS specifically

Question 44

Metabolic side effects (usually transient) of epinephrine infusion

Answer 44

Lactic acidosis Hyperglycemia Hypocarbia (low HCO3)

Question 45

In HLHS, the best echocardiographic way to assess adequate atrial communication (i.e. blood flow)

Question 46

The most common cause of *neonatal* SVT (supraventricular tachycardia)--multiple names

Answer 46

AVRT (atrioventricular reentrant tachycardia OR reciprocating tachycardia) "Orthodromic reciprocating tachycardia" *An accessory pathway that can bypass AV node; differs from the most common cause when older, which is AV**_N_**RT*