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18 Cards in this Set
- Front
- Back
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Most common arrhythmia in children.
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Sustained Super Ventricular Tachycardia (SVT)
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What gene defects are involved in Marfan Syndrome?
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Fibrillin (15q21) mutation
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What cardiac defect is frequently found in patients with Down Syndrome?
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AV Communis
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What gene defects are involved in congenital hypertrophic cardiomyopathy?
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Actin, myosin, troponin, tropomyosin gene defects
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What gene defects are involved in heterotaxy syndromes?
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Genes that control looping and sidedness
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What are the physiologic differences in fetal circulation (as opposed to adult circulation)?
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High resistance pulmonary bed (lungs non-fnal)
Low resistance placenta High rate of brain growth |
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What shunt pathways are present in fetal circulation?
How does each shunt differ in function? |
Ductus venosus --allow high O2 blood to bypass the liver
Foramen ovale: along with esutachian valve brings high O2 to left heart (-->brain) Ductus arteriosus: bypasses high resistance of pulmonary vascular bed |
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What anatomic differences occur at birth that affect shunt pathways?
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Loss of low resistance placenta (reduced UA flow constricts ductus venosus)
First breath reduces PA vascular resistance and increases arterial O2 (constriction of ductus arteriosus) Inc'd pulmonary blood flow and venous return-->fnal closure of foramen ovale |
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How does persistent pulmonary hypertension of newborns occur?
What effects does this have on fetal shunts? |
AKA PERSISTENT FETAL CIRCULATION
Failure of pulmonary vascular resistance to fall normally at birth Leads to elevated R heart pressure Dec'd pulmonary blood flow R-L shunt at Patent Ductus Arteriosus R-L shunt at Foramen Ovale Cyanosis and Right HF |
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Management of persistent pulmonary hypertension?
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Sedation
Supplemental O2 Pulmonary vasodilators (NO) Treat underlying cause (sepsis, meconium aspiration pneumonitis--doo doo) |
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What structural malformations can result in LEFT to right shunts?
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VSD
ASD Patent DA |
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What structural malformations can result in RIGHT to left shunts?
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Tetralogy of Fallot
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What structural malformations can result in obstructive lesions?
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Aortic Stenosis
Pulmonic Stenosis |
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What factors determine direction of shunting in cardiac septal defects?
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Pulmonary vascular resistance is less in pulm bed than systemic bed (SVR>PVR)
IF pulmonary HTN of newborn (PVR>SVR): flow is right to left At any given hole, volume and direction of flow determined by: -Size of hole (big hole-->more flow) -Resistance -Higher the HCT, less flow over VSD; lower HCT, more flow (not important, this is constant) |
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What are the physiologic consequences of LEFT ro right shunts?
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Chronic pulmonary overcirculation (dec'd lung compliance, lymphatic congestion; pulmonary venous HTN-->pulmonary edema; pulmonary vascular obstructive dz)
Dec'd systemic blood flow to kidney/adrenal (activation of renin-Ag, inc'd catechols) CHF--often biventricular (hepatomegaly, tachypnea, peripheral and pulmonary edema; dyspnea upon exertion--age appropriate, e.g., feeding, playing, chronic napping, not climbing a flight of stairs) |
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What are the physiologic consequences of RIGHT to left shunts?
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(This is referring to Tetralogy of Fallot)
Cyanosis (decreased pulmonary blood flow), leads to exercise intolerance Inc risk of endocarditis, brain abscess Inc risk of thromboembolism, stroke Erythrocytosis (inc blood ciscosity) End organ dysfn due to chronic hypoxemia (leads to altered brain growth, altered growth in general) Slow growth, FTT GEt pulmonary stenosis If no pulmonary stenosis, will act as a simple VDF (will be left to right shunt) As resistance of pulm stenosis increases, and allows blood to travel right to left |
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Tetralogy of Fallot:
Treatment |
Complete Repair:
VSD is patched closed Transannular incision made to insert patch over pulmonary artery Remove obstruction, taken out valve (but leads to pulmonary regurgitation, which leads to volume load, but it's well-tolerated for a while, eventually RV will suffer and pt will need pulmonary valve replacement) (RV outflow obstruction removed and patch placed to close VSD Patch is then placed over RV outflow tract (over pulmonary trunk) to address all levels of obstruction) |
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Single Ventricle:
Treatment |
Hypoplastic L/R heart = Single Ventricle
Don't have two separate ventricles Treatment: Fontan Procedure: Flow into lungs is passive (low pulmonary resistance) Stage 1 Surgery: Norwood Reconstruct aorta Main Pulmonary Artery has been dissected out and fashioned into ascending aorta Shunt directs O2 blood into body Stage 2: Bidirectional Glenn SVC removed from RA and placed directly on Pulmonary Artery (can't be done as a newborn) Stage 3: Modified Fontan Conduit placed within RA and excludes blue blood from red blood SVC and IVC now feed directly into pulmonary artery, leave a small hole between RA and IVC to allow some exchange (buffers pressure) |
