Cardiolgy ♥️ Flashcards

1
Q

Heart lesion with reverse differential cyanosis

A

D - TGA with PDA and PPHN, interrupted aortic arch or coarctation of aorta

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2
Q

Mechanism of action of milrinone

A
  1. Phosphodiesterase 3 inhibitor—increased cAMP
    * * Decreased breakdown of cyclic AMP->perpetuating Ca influx —> improve systemic blood flow
  2. Improved ventricular function Inotropic, inodilator (promotes cardiac contractility) lusitropic (promotes relaxation)
  3. Decreases SVR

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

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3
Q

HLHS

A

7-9% of congenital ♥️ defects

RV + tricuspid valve represent systemic ventricle + AV valve

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4
Q

Describe normal neonatal ECG findings

A

Normal QRS measured in V5 20-80msec

QRS axis ranges from +55 to 200+ in terms and +65-+174 in preterm

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5
Q

Predominant myocardial substrate prenatally and postnatally

A

Prenatally glucose and lactate

Postnatally fatty acids

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6
Q

The factor that causes the most significant change in blood flow with minor alteration is

A

Radius/diameter

R proportional 8x viscosity x L/pi x rx4

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7
Q

Responsible for pulmonary vascular changes at delivery

A

NO

Arachidonic acid metabolites

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8
Q

Patients with Pompes have which ECG finding?

A

Short PR interval and biventricular hypertrophy given hypertrophic cardiomyopathy

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9
Q

Noonan Syndrome findings

A
Hypertelorism
Downward eye slanting 
Low set ears 
Short stature
Pulmonic stenosis (60%) 
Web neck 

**Noonan’s syndrome is the MCC of hypertrophic cardiomyopathy in neonates and children < 4yo
Hypertrophic cardiomyopathy

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10
Q

Rapid heart rate with atrial contractions precede ventricular contractions, atrial rate 180-240 which seems to speed up and slow down. What is diagnosis?

A

Ectopic atrial tachycardia

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11
Q

The most common non renal association with hypertension in preterm is?

A

BPD

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12
Q

Approach to management of HLHS is?

A

Norwood palliation

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13
Q

Treatment of fetal SVT vs AVnRT (atrioventricular nodal reentry tachycardia)

A

SVT is Digoxin

AVNRT is amiodarone

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14
Q

How does hydrocortisone express myocardial action in hypotensive patients?

A

Inhibits expression of nitric oxide synthase and vasodilators prostaglandin action

Upregulation of CV adrenergic receptors (vasoconstriction, inc Co, inc BP)

Upregulation of angiotensin II receptors to increase vascular resistance

Inhibits catecholamine metabolism and release of vasoactive factors

Inc in intracellular Ca concentration (enhances cardiac responsiveness to catecholamines)

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15
Q

Which genetic polymorphism is associated with abnormal neuro development at 1 year post cardiac surgery?

A

Genetic polymorphisms in apolipoprotein E

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16
Q

Which population of NICU patients should avoid ACE inhibitors

A

Preterm
Renal failure
Hypokalemia

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17
Q

Describe findings in HLHS and subtypes

A

Severe MV and AV stenosis/atresia
Hypoplastic LV
Aortic arch hypoplasia

30% mitral and aortic atresia
25% mitral stenosis and aortic atresia (high risk 2/2 presence of coronary-cameras fistulas in 50%)
45% mitral and aortic stenosis

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18
Q

Dopamine acts on which receptors at which doses?

A

Alpha 1: vasoconstriction (6-10)
Beta 1 and 2 chronotropy (HR) and contractility (2-6)
Dopaminergic at low dose (2-4) renal vasodilation and splanchnic vessels
At high dose 10-20, increases PVR via alpha 1

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19
Q

Hyperpercapnic-induced vasodilation in CBF is mediated by:

A

Hydrogen ion concentration requiring basal nitric oxide

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20
Q

Norepinephrine works where?

A
  • endogenous catecholamine
  • increases SVR and CO by alpha 1,2 and beta 1 receptors
  • constricts systemic vascular&raquo_space; pulmonary vascular
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21
Q

Mechanism of action of dobutamine

A

Acts directly in alpha and beta receptors without release of Norepi

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22
Q

Hydrocortisone side effects

A

Hyperglycemia
Osteopenia
Inhibits immune function and somatic growth
Associated with SIP if concurrent indomethacin

Aid in hypotension by decreasing breakdown of catecholamines, inc Ca in myocardial cells and upregulating adrenergic receptors

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23
Q

Which mutations have been found in HLHS?

A

HAND1 and NOTCH1

Recurrence HLHS sibling 8%
Recurrence of any congenital is 22%

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24
Q

What abnormalities are seen in Ebstein anomaly?

A

Apical displacement of septal and posterior leaflet of TV (atrial I zing the RV)

WPW (60%)
Right bundle branch block (70-80%)

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25
Most commonly affected gene in long QT syndrome
KCNQ1- potassium channel gene | Abnormalities Associated with this gene also correlate with A fib later in life
26
What is the difference in functional vs fractional saturation of hgb?
Functional measures oxyHb and reduced Hb alone Fractional saturation measures oxyHb ans. reduced Hb. And approximates carboxyHb and methHb. Functional Hb 1.6-2 points higher than fractional saturation.
27
Most Common CHD in maternal diabetes
VSD Double outlet RV Truncus Arteriosus
28
What is therapy of hypertrophic cardiomyopathy in IDM neonates?
B blockers Maintenance fluid Contraindicated-inotropic support bc can make condition worse
29
What is the prognosis of HCM in neonate born with maternal diabetes?
excellent with resolution of ventricular hypertrophy at 1 mo of age Mainly diastolic dysfunction
30
How is BP affected in preterms? Ie relative to SVR
Preterms may have low systemic blood flow because of structure of preterm myocardium is less able to overcome increased SVR after birth
31
How is preterm blood pressure influenced by chorioamnionitis
Chorio is associated with hypotension —> caused by release of inflammatory mediators (IL -1 and TNF)
32
When does cyanosis occur in neonates?
With drop of 3-5g/dL of Hgb of reduced Hgb Cyanosis is more visible in polycythemic than in anemic babies Cyanosis notable at this %saturation Hb: Reduced Hgb/total Hgb
33
Vasopressin mechanisms of action
Minimal chronotropic effects | Vasoconstriction during hypoxemia and acidosis
34
Which is the most common cause of HCM in neonates and children <4years?
Noonan syndrome
35
Describe Heart embryology and GA at formation
Arises from mesoderm Right sided or dextro looping at 21 days Septation at 3-4 weeks Functional at 8 weeks
36
In utero, what percentage does the RV and LV supply to fetus?
66% RV 34% LV 7-15% of total blood volume goes to fetal lungs
37
Name the order from highest to lowest O2: | Umbilical artery, vein, uterine artery and vein
Uterine artery, uterine vein, umbilical vein, umbilical artery
38
How does the fetus compensate for hypoxemic environment?
Increase in erythropoietin Fetal hemoglobin Decreased O2 consumption
39
How can you increase stroke volume?
Increase EDV by inc preload or inc ventricular compliance | Decrease ESV by inc contractility and dec afterload
40
How best does the neonate regulate CO
HR | Preload
41
What target conditions does critical congenital heart screening identify?
``` HLHS Pulmonary Atresia with intact septum Tetralogy of Fallot TAPVR TGA Tricuspid Atresia Truncus Arteriosus ```
42
Describe the surgical repair for HLHS
Norwood Stage 1 Atrial septectomy (creating pop off for LA) — preventing pulmonary venous congestion Proximal portion of MPA —-> ascending aorta (to provide systemic circulation) Systemic - pulmonary artery shunt to provide systemic blood flow (BT shunt - subclavian to pulmonary artery to ensure adequate pulmonary blood flow) Stage 2 - BiDirectional Glenn Decrease volume overload on RV Remove BT - connects SVC directly to pulmonary artery (increasing pulmonary blood flow without increasing RV volume load) ``` Stage 3 - modified Fontan Reroutes IVC (to now meet SVC) to PA to create separate systemic and pulmonary circulation ``` This occurs in multi step process to allow pulmonary pressures to decrease GLENN (G for Glenn) goes FIRST (F for Fontan)
43
Tetralogy of Fallot
RVH PS Overiding Aorta (allowing blood to leave both LV and RV) VSD - Right sided obstructive lesion
44
Variation in which enzyme has been associated with TOF?
ALDH1A2 (enzyme imp in retinoic acid production)
45
Genes associated with TGA
NODAL and FOXH1
46
Workup of dilated cardiomyopathy
Echo for ALCAPA Viral PCR Genetic/metabolic
47
In hypoxic condition the major pathway for energy production in neonatal heart is?
Lactate dehydrogenase (facilitates reduction of pyruvate to lactate reflecting anaerobic glycolysis)
48
Differentiate mechanism of action of Epi at low dose and high dose
Low dose 0.01-0.1mcg/kg/min Stimulates beta receptors enhancing myocardial contractility and peripheral vasodilation High dose >0.1mvg/kg/min stimulates alpha receptors causing peripheral vasoconstriction and increase SVR Remember it is a non selective alpha agonist and activates both B1 and B2 adrenergic receptors
49
How does fetal heart facilitate glucose uptake??
Glucose transporters GLUT1 and GLUT4 GLUT1 plays primary role in bringing glucose into the cardiac monocyte Prenatally GLUT1 >>GLUT4 Postnatally GLUT4 > GLUT1
50
Treatment of SVT with WPW
Propanolol
51
Timing of CHD Presentation
TGA —-> 1-2 days HLHS —-> 3-7 days Coarctation Ao —> ~14 days VSD —> ~4-6 weeks
52
3.2 kg baby with tachypnea + poor perfusion. Pre/post sats 82%. O2 via hood worsens condition. Placed on ventilator (TV 20ml, PEEP 6, iT 0.35, FiO2 70%) CBG - 7.24/38/46/18/-8. Saturations are still low (~75%) What is the next step in management?
Decrease TV Decrease rate Decrease FiO2 In HLHS - oxygen worsens the condition due to steal of blood from PDA Newborn Baby within 1st week of worsening with O2 - T/C HLHS
53
Qp/Qs calculation | >1
Ao sat-SVC sat/RV sat-PV sat >1 L to right shunt (inc PBF) <1 R to L shunt (PPHN) Remember inverse (systemic/pulmonary)
54
Which type of heart failure does PDA lead to?
Left to right shunt | Therefore, left sided heart failure
55
Characteristics of Fetal Circulation
Oxygenated blood —> placenta —> IVC —> RA (SVC brings deoxygenated blood so mixing occurs) —> RV —> PA —> PDA —> descending Ao Oxygenated blood —> placenta —> IVC —> Ductus Venosus —> LA (PFO) —> ascending Ao ** LA, LV, ascending Ao have the highest PO2
56
Name Contracting and Dilating Mediators For example - PDA closure occurs with increasing contracting mediators and decreasing dilating mediators
``` Constrictors PGF2α Αcetylcholamine Bradykinin Oxygen ``` ``` Dilators PGE1 PGI2 (prostacyclin) Hypoxemia Acidosis ```
57
EKG Measurements
HR - big boxes - 300 —> 150–> 75 1 big box = 0.2 seconds or 200 milliseconds 1 small box = 0.04 seconds = 1 millivolt
58
Describe the expected pressure measurements with umbilical catheter in IVC, Aorta, LA
IVC - 1-3 mmHg Ao - should approach systemic means LA - mean pressure of 8mmHg
59
Calculate Mean Blood Pressure
Mean BP= Diastolic + 1/3 (SBP - DBP) ** Remember to average blood pressures if given more than one)
60
Indirect Measure of cerebral perfusion
SVC blood flow + Doppler SVC flow reflects upper body venous return and is less influenced by shunts May reflect cerebral perfusion
61
Describe echo findings of dilated cardiomyopathy in terms of - shortening fraction - ejection fraction - left ventricular dimension Z score
Shortening fraction <25% EF<40% LV dimension Z score greater than 2
62
Which mediator is decreased in expression in pulmonary casualties in idiopathic pphn?
Endothelial nitric oxide synthase and downstream target soluble guanylate cyclase Remember endothelin 1 plays goal in maintaining high vascular tone in utero
63
T or F | Blood pressure has a strong relationship with cardiac left ventricle output
False BP is a function of both blood flow and SVR. Weak relationship between LV output and mean BP
64
Physical exam findings in HLHS
Hyperdynamic precordial activity reflects right ventricular volume and pressure overload Decrease in amplitude of peripheral pulses only after ductal constriction Single S2 if aortic atresia present Murmur for TR
65
Primary site of fatty acid oxidation regulation by fetal and neonatal cardiac myocytes is
Carnitine palmitoyltransferase
66
Wandering atrial pacemaker is most associated with:
High vagal tone
67
The BT shunt involves shunting from which vessels?
Subclavian artery to ipsilateral pulmonary artery
68
Ductal patency in utero depends on which 3 substances
PGE2 Prostacyclin Thromboxane 2
69
Describe 4 mechanisms how fetus tolerates lower pO2
1. Fetal hemoglobin 2. Increased O2 carrying capacity bc of elevated Hgb in fetus 2/2 hypoxemic erythropoeitin production 3. Decreased O2 consumption 4. Increased ability to utilize glucose by anaerobic metabolism
70
Describe 3 Mechanisms by which fetus compensated for worsening hypoxemia
Blood flow preferentially goes to heart brain and adrenals Dilation of DV so more oxygenated blood goes to left side of heart Fetus goes into hybernation mode
71
What is the % of fetal blood flow in 2nd trimester? In 3rd trimester?
7-15% (2nd trimester) 35% (fetal growth)
72
How does the fetus adjust to | the relatively low intra utérine oxygen environment ?
Epo Fetal Hb (high affinity for oxygen which allows for increased oxygen uptake even in hypoxia environments) Decreased oxygen consumption
73
How does fetal | Heart increase cardiac output ?
CO = SV x HR fetal tachycardia—> increases cardiac output
74
Describe a pt with Qp/Qs>1
Tachypnea, FTT, CHF
75
Baby with cyanosis, acidosis and tachypnea. What’s the Qp/Qs?
Qp/Qs<1
76
In a patient with cardiac tamponade how does the blood pressure change?
Pulsus paradoxus is a decrease in systolic blood pressure during spontaneous inspiration Pulsus paradoxus is a common finding in cardiac tamponade in a spontaneously breathing patient. Because systolic blood pressure normally increases during inspiration while receiving positive pressure ventilation, reversed pulsus paradoxus is observed in patients with cardiac tamponade who are receiving mechanical ventilation.
77
List disorders associate with single S2
S2 is closure of aortic and pulmonary valve Single S2 heard with: - Pulmonary hypertension (both close at same time) - 1 semilunar valve (PA, aortic atresia, truncus, TOF/absent PV) - P2 not heard (TGA, TOF, severe PS)
78
Single S2 with bounding pulses. Dx?
Truncus arteriousus Single S2 because one arterial vessel exiting heart Bounding arterial pulses because of diastolic runoff into PA
79
Which enzyme do catecholamines (ie dopamine) regulate for renal solute transport and Na absoption?
Basolateral Na/K ATPse (increased Na absorption)
80
Hypertrophic cardiomyopathy is seen with which genetic conditions?
Noonan Beckwith Weideman Costello Syndrome (fasciocutaneoskeletal syndrome) Eagle Barrett (prune belly)
81
Side effects of dopamine use
Decreased thyroyropin Deceased prolactin Decreased thyroxine Increases PVR
82
Long term dopa use (> 12 h) does what to the heart?
Depleted norepinephrine stores
83
Right and left differentiation begins during which stage of embryonic development?
Gastrulation
84
What suggests R > L shunting?
> 15 torr difference in pre/post ductal paO2 | >10% difference in O2 saturations