Cardiology Flashcards
Most common cause of vascular ring?
double aortic arch
Fetal circulation - what has lowest amount of O2?
SVC - lots of extraction by brain. LV > RV bc blood in LA is mixture of UV and L pulmonary blood flow
Blood pressure = _____ x ______
CO x SVR
Infants with high lying UAC show fewer / more clinically obvious ischemic complications. HTN is ______ in upper and lower catheters.
High lying catheters = fewer complications.
HTN is SAME in upper and lower
MCC HOCM in neonates and children under 4 years old
Noonan syndrome. Autosomal dominant. Pulmonic stenosis, hypertelorism, downward slanting palpebral fissures, short webbed neck, cryptorchidism
Oxygen causes ______ of PDA
vasoconstriction of PDA
first line treatment for atrial flutter?
digoxin
Etiology of TOF
multifactorial; overall 3% recurrence rate
When does cardio genesis begin?
First heart beat?
5th week - formation of paired heart tubes. Tubes fuse and fold
Heart beat starts at 6 weeks
Separation occurs b/w embryonic 7-8 weeks
Conotruncal abnormalities?
DORV, TOF, TGA
AV canal is AV septal defect
Embryologic origin of PDA?
L 6th aortic arch
1-2 arch: disappear early in gestation, 1st becomes maxillary
3rd: carotid artery
R 4th: R subclavian, L 4th becomes aortic arch
5th involutes
Bulbus cordis is part of primitive heart and is known as conotruncus
_______ is source of prostaglandins that maintain ductus in utero
placenta
Congenital heart disease is more common in donor or recipient in TTTS
RECIPIENT. 3x increase in frequency of CHD. Most frequent defects are VSDs, pulmonary stenosis
Shunt equation =
Qs (blood shunted away from lungs) / Qt (total blood volume) = (CcO2 pulmonary capillary - pulmonary arterial) / (pulmonary capillary - pulmonary venous)
Prolonged use of dopamine can result in _____
reduced inotropic effect due to depletion of NE stores in myocardium
epinephrine side effects
lactic acidosis, hyperglycemia (beta 2)
Most clinically significant PDA _______ in first few days of life
clinically silent; but, most common time for pulmonary hemorrhage is first 72 hrs
Wide pulse pressure is NOT helpful in looking for PDAs. What is?
global hypotension
Digoxin mechanism of action
positive inotrope and negative chronotrope. Inhibits sarcolemma Na/K ATP –> enhances contractility by increasing intracellular sodium and calcium. Decreased chronotropy due to prolonged sinoatrial conduction rates.
Most common congenital heart disease
VSD
Most common CHD in VACTERL
VSD (50%)
Endocardial cushion defect —> _____ axis deviation
superior
Egg shaped cardiac silhouette and narrow mediastinum is _______
D-TGA
Most common type of VSD is
perimembranous
Normal QRS axis in term neonates
+55 to +200
Before birth, predominant substrate taken up and oxidized by fetal heart are
glucose and lactate prenatally
postnatally, primarily fatty acids
Primary endothelial products for pulmonary vascular changes during transition are _______
NO and arachidonic acid metabolites
Describe ectopic atrial tachycardia
distinguished by “warms up” and “slows down”, atrial rates 180-240
Where does vasopressin act in kidney
V2 receptor = water retention in renal tubule
Most common association with non-renal HTN in neonates is
BPD. 13-43%.
Mechanism - increased systemic arterial stiffness
Treatment for fetal SVT
digoxin
Hydrocortisone mechanisms on CV action
Inhibition of expression of inducible nitric oxide synthase and vasodilatory prostaglandin action
Up regulation of CV adrenergic receptors —> vasoconstriction, increased CO, increased BP
Upregulate Angiotensin II receptors and their second messenger systems
Inhibit catecholamine metabolism, release of vasoactive factors
Increase in intracellular calcium concentration, enhancing myocardial and vascular responsiveness to catecholamines
Most common abnormality on pre-surgical MRI for patients with complex CHD
white matter injury + infarction
3 subtypes of HLHS are
mitral atresia + aortic atresia (30%), mitral stenosis and aortic atresia (25%), mitral stenosis and aortic stenosis (45%)
Mitral stenosis + aortic atresia —> high risk bc presence of coronary-cameral fistulas
How is hypercapnia-induced vasodilation mediate?
extracellular H+, which requires basal level of nitric oxide
Mutations for HLHS are? Recurrence risk?
HAND1 and NOTCH1
Sibling recurrence risk is 8% for HLHS and 22% for any CHD
Association with CHD and arrhythmias?
60% of patients with epstein’s anomaly have WPW, 70-80% have RBBB
Most commonly affected gene in long QT is
KCNQ1
IDM increases risk for
VSD, DORV, truncus
Typical course of HOCM associated with maternal DM
regression/resolution of ventricular hypertrophy at 1 month of age
Syndromes associated with HLHS
Jacobsen and Holt-oram syndrome
How to determine adequacy of atrial communication on doppler
pulmonary venous flow
Where does dobutamine act?
Dobutamine is a synthetic sympathomimetic that acts directly on alpha and beta receptors without the release of NE
Primary target of CCHD screening
HLHS, pulmonary atresia with IVS, TOF, TAPVR, TGA, TA, Truncus arteriosus
CCHD will miss ______ neonates. most false negatives are?
1 in 5;
coarct, IAA
What gene mutation is associated with cases of TOF? (not diverge)
Variation in ALDH1A2, enzyme important for retinoid acid production
What genes associated with TGA?
TGA - ZIC3, PITX2C, FOG2, NODAL, NKX2-5, FOXH1
Mechanism for epi drip
nonselective alpha-agonist, activation of both beta1 and beta 2 —> increases BP and systemic blood flow
What mediates uptake of glucose in fetal heart?
glucose transporters GLUT1 and GLUT4
What causes differential vs reverse differential cyanosis
Differential cyanosis is usually caused by severe coarct or IAA
Reverse differential cyanosis = TGA with PDA in presence of severe coarct, IAA, or pulmonary HTN
MCC neonatal HTN
coarctation
Pass vs fail CCHD
Fail screening is <90%, SPO2 < 95 on 3 measurements separated 1 hr apart, difference is greater than 3 on 3 measurements, each separated by 1 hr
Pass screening: > 94, <4% diff
Features on echo for DCM
SF < 25%, EF < 40%, LV dimension z score > 2
Blood pressure at birth is ____ and ____ over first few days
low, increases
Physical exam feature of HLHS
hyper dynamic precordial activity
What enzyme regulates fatty acid oxidation by fetal and newborn heart
Carnitine palmitoyltransferase
Describe Norwood procedure
Norwood: main PA is transected and reconstructs aortic arch.
Then Put in BT shunt to connect subclavian or innominate artery to ipsilateral pulmonary artery (pulmonary blood flow)
100a
What is wandering atrial pacemaker?
shift of pacemaker from usual location in sinus node to other sites in atrium and in AV junction
Tuberous sclerosis gene
chromosomes 9 + 16
Why does NO not cause systemic vasodilation?
When the gaseous nitric oxide molecules reach the vasculature, they bind to hemoglobin, become oxidized to NO2 and NO3, and are inactivated. Thus, peripheral vasodilation does not occur following administration of inhaled nitric oxide
MC type of VSD
Perimembranous VSD (70%) is MCC; muscular is 25%; these two often close spontaneously
What is Wenkebach?
Mobitz Type I; increasing PR interval and then non-conduction
XR - egg shaped heart, narrow mediastinum
D-TGA; single loud S2 (PV is farther from chest), limiting ability to detect P2
Endocardial cushion defect, T21 ECG
superior axis deviation
First line tx for atrial flutter
digoxin
Cardiogenesis embryopathy
Cardiogenesis begins week 5 - paired heart tubules. Tubes fuse and fold shortly after.
Heartbeats at week 6
Septation at weeks 7-8
What receptor causes side effects from epinephrine
Epi causes lactic acidosis, hyperglycemia, tachycardia due to BETA2
How long before dopamine causes depletion of NE in myocardium?
12 hrs
side effects: decreased thyrotropin, prolactin, thyroxine, increased PVR
What do tall peaked P waves mean?
R atrial enlargement = abnormal = needs investigation
