Term
| what does congenital heart disease refer to? when do most arise? |
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Definition
| abnormalities of the heart or great vessels present since birth. most congential heart disease arises from faulty embryogenesis during the gestational weeks 3-8 |
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Term
| what happens to most severe cardiac abnormalities? |
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Definition
| they are incompatible with intrauterine survival |
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Term
| what characterizes the majority of congenital heart diseases? |
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Definition
| many are morphogenic defects of individual chambers/regions of the heart w/the rest of the heart developing normally |
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Term
| even if the muscular component develops normally can problems with the vasculature still lead to congenital heart disease? |
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Definition
| yes, vessels may not have the appropriate connections with specific cardiac chambers |
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Term
| can some congenital heart defects remain "silent" until later in life? |
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Definition
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Term
| can some congenital heart problems still remain, even after surgery? |
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Definition
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Term
| what is the most common heart disease among children? |
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Definition
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Term
| what is the prevalence for congenital heart disease? |
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Definition
| 1% of live births -> higher in premature infants and stillbirths. in the past few decades, incidence has risen due to increased diagnostic sensitivity |
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Term
| why are autopsies done on children who are suspected of dying due to congenital heart disease? |
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Definition
| to r/o congenital heart disease that may affect other future children |
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Term
| what are 2 of the most common congenital heart diseases? |
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Definition
| ventricular septal defect and atrial septal defect, followed by pulmonary stenosis, patent ductus arteriosus, and tetralogy of fallot (in order) |
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Term
| what does coarctation of the aorta have a strong association with? |
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Definition
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Term
| what is congenital heart disease caused by? |
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Definition
| genetic and environmental factors |
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Term
| what kinds of genetic problems can cause congenital heart disease? |
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Definition
| certain chromosomal abnormalities: trisomies 13,15,18,21 - *with down syndrome being the most common known genetic cause of congenital heart disease* |
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Term
| what kinds of environmental problems can cause congenital heart disease? |
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Definition
| rubella, infections or teratogens in some cases |
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Term
| can distinct congenital heart syndromes share a common pathogenesis? how does this help w/treatment? |
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Definition
| yes, distinct congenital heart syndromes can share errors in mesenchymal tissue migration (common pathogenesis). this allows for more accurate prediction of certain abnormalities as well as categorization |
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Term
| what might anomalies of outflow be due to? |
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Definition
| failure to fuse or failure to separate |
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Term
| can issues with structures in the heart be linked to issues with structures in the mediastinum/neck/face? |
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Definition
| yes, they share common developmental pathways, and therefore problems in development can affect any and all involved |
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Term
| what is the main known cause of congenital heart disease? |
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Definition
| sporadic genetic abnormalities - which can lead to single gene mutations, small chromosomal deletions, vegetations, or deletions of whole chromosomes |
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Term
| mutations in which genes are associated with atrial septal defects and ventricular septal defects? |
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Definition
| genes encoding for transcription factors NKX2-5, GATA-4 and TBX20 are associated with atrial septal defects and ventricular septal defects |
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Term
| what gene mutations affect proteins within *signaling pathways or have *structural roles in congenital heart disease? |
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Definition
| JAGGED1, NOTCH1, and NOTCH2 |
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Term
| what is digeorge syndrome? |
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Definition
| digeorge syndrome is associated with the lesion of *chromosomes 22q 11.2, the *fourth branchial arch and derivatives of the *third and fourth pharyngeal pouches develop abnormally leading to abnormal formation of the thymus (immune problems), parathyroids and heart |
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Term
| what does "outflow" tract refer to? |
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Definition
| how the blood is flowing out of the ventricle - so the aorta and pulmonary artery |
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Term
| what are defects in the outflow tract often related to? |
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Definition
| abnormal development of neural crest cells |
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Term
| what problems with congenital heart development other than digeorge syndrome also involve chromosome 22? |
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Definition
| development of the conotruncus, the branching arches, the face, thymic abnormalities, cranio-facial defects, and anomalies of the fourth branchial arch/third and fourth pharyngeal arches. |
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Term
| what can hypoplasia of the thymus and parathyroids (as often associated with chr 22) lead to? |
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Definition
| abnormalities in the thymus results in immune deficiencies (recurrent infections), and if the parathyroids are involved, there will likely be problems w/Ca++ metabolism (usually hypocalcemia) and present with neurological problems such as seizures |
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Term
| what are some common environmental factors associated with congenital heart disease? |
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Definition
| environmental teratogens, congenital rubella infection, gestational diabetes, and nutritional factors (intake of *folate may reduce risk of congenital heart defects*) |
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Term
| what are the broad categories that congenital heart defects can be broken down into? |
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Definition
| L->R shunts, R->L shunts, cyanotic, non-cyanotic |
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Term
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Definition
| abnormal communication between chambers or blood vessels which allows blood to pass from R -> L or vica versa depending on pressure relationships |
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Term
| what characterizes a R -> L shunt? |
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Definition
| cyanosis occurs due to decreased pulmonary flow and poorly oxygenated blood enters systemic circulation |
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Term
| what are the common L -> R shunts? |
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Definition
| ASD, VSD, PDA, compete atrioventricular canal defect and large VSD w/irreversible pulmonary HTN (blood moves from a higher pressure gradient to a lower one) |
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Term
| what is ASD? is it usually symptomatic? can pulmonary HTN develop w/it? |
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Definition
| an abnormal opening in the atrial septum with communication of blood between the L and the R atria. it is *usually asymptomatic until adulthood (can present as a murmur or pulm problems) due to a low pressure difference between the atria. irreversible pulmonary HTN does develop in less than 10% of pts w/uncorrected ASD |
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Term
| what are the different types of ASD? |
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Definition
| secundum, primum, and sinus venosus |
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Term
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Definition
| this accounts for 90% of ASDs, which have a deficient or defenestrated fossa ovale atrial aperture. it may be single, multiple or fenestrated. usually this arises from an enlarged foramen ovale, inadequate growth of the septum secundum, or excessive absorption of the septum primum. |
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Term
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Definition
| primum ASD is adjacent to the AV and is usually associated with a cleft anterior *mitral leaflet -> therefore it be associated with changes to the *mitral valve |
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Term
| what is sinus venosus ASD? |
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Definition
| sinus venosus ASD is a type of atrial septum defect in which a defect in the septum involves the venous inflow of either the superior vena cava or the inferior vena cava to the R atrium. it is usually associated with *anomalous connections of the R pulmonary veins to the SVC or the R atrium |
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Term
| what are complications associated with ASD? |
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Definition
| think about high pressure going from the L -> R. cor pulmonale (the R atrium becomes engorged w/blood, leading to pulm HTN, leading to R sided heart failure), cardiac cirrhosis (passive congestion of the liver due to R sided heart failure impinges on hepatocytes leading to pressure atrophy which creates fibrosis), and paradoxical embolization (something from the L side of the heart emobolizes backward to the R side) |
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Term
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Definition
| incomplete closure of the ventricular septum w/free communication and a L->R shunt. it may present with other anomalies (tetralogy of fallot) and clinical presentation depends on the size of the defect. (it is the most common congenital heart problem) |
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Term
| what are most VSDs the size of? what structure do 90% of VSDs involve? the rest? are they single or multiple? |
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Definition
| most VSDs are the size of the aortic valve orifice. 90% of them involve the *membranous septum and the rest lie below the PV (infundibular VSD) or on the muscular septum. most are single, but some may be multiple |
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Term
| can VSDs close spontaneously? |
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Definition
| yes, 50% of VSDs close spontaneously |
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Term
| what can large VSD defects lead to? |
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Definition
| a L -> R shunt that can result in irreversible pulmonary disease (if not treated = cyanosis and death) |
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Term
| what are the R -> L shunts? |
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Definition
| tetralogy of fallot, transposition of the great arteries, persistent trunctus arteriosus, tricuspid atresia, and total anomalous pulm venous connection |
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Term
| what are paradoxical emboli what kind of shunts are they often associated with? what are possible complications? |
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Definition
| paradoxical emboli are associated with R -> L shunts and typically arise in peripheral veins that can bypass the lungs and enter systemic circulation w/brain infarcts and abscesses being possible complications (do not produce a pulm embolism) |
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Term
| what is patent ductus arteriosis? what disease is it commonly seen with? are they often associated with other anomalies? |
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Definition
| patent ductus arteriosis results when the ductus arteriosus remains open after birth, and is commonly seen with rubella infections. most instances are isolated, others can be associated with other anomalies. |
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Term
| do most cases patent ductus arteriosus cause functional problems at birth? how do they present upon auscultation? |
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Definition
| patent ductus arteriosus (pulmonary artery to the aortic arch) usually does not cause functional issues at birth but does usually present with a machinery-like murmur |
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Term
| what direction does blood flow at first with patent ductus arteriosus? |
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Definition
| L -> R w/no cyanosis but obstructive pulmonary vascular disease ensues with reversal of flow and its consequences (cyanosis) |
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Term
| what do atrioventricular septal defects result from? |
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Definition
| abnormal development of embryologic AV canals, where the superior and inferior endocardial cusions fail to fuse - causing incomplete closure of the AV septum and inadequate formation of the TV and MV (adjacent structures are often affected) |
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Term
| are there different kinds of atrioventricular septal defects? |
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Definition
| yes, partial and complete |
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Term
| what is involved with partial atrioventricular septal defects? |
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Definition
| in this case, *primum ASD has a cleft of the anterior mitra valve leaflet and can produce *mitral insufficienct |
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Term
| what is involved with complete atrioventricular septal defects? are there other commonly associated diseases? |
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Definition
| this is a large combined aortic valve defect, where *all four chambers freely communicate - resulting in significant mixing of blood from all 4 chambers. this causes hypertrophy in various areas of the heart and is often associated with *down's syndrome |
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Term
| what is tetralogy of fallot? |
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Definition
| classically 4 abnormalities, which starts at 2 that cause other complications. anteriorsuperior displacement of the infundibular septum leads to *VSD and an *overriding aorta. the overriding aorta causes *obstruction of the R ventricular outflow tract, which results in *RVH |
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Term
| what do the clinical consequences of the tetralogy of fallot depend on? what determines the direction of blood flow? |
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Definition
| the clinical consequences of the tetralogy of fallot depend on the severity of the subpulmonary stenosis and the severity of the obstruction to the R ventricular outflow determines the direction of blood flow |
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Term
| when would the tetralogy of fallot result in a simple L to R shunt w/o cyanosis? |
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Definition
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Term
| when would the tetralogy of fallot result in a simple L to R shunt with cyanosis? |
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Definition
| if the stenosis increases and there is greater resistance to R ventricular outflow |
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Term
| what happens in the tetralogy of fallot if there is greater subpulmonary stenosis? |
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Definition
| the pulmonary arteries get smaller and thinner while the aorta increases in diameter (dilates) |
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Term
| what is the morphology of hearts affected by tetralogy of fallot? |
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Definition
| the heart is often large and "boot-shaped" (visible on CXR), VSD is large and the aortic valve forms the superior border of it - overriding the VSD and both ventricular chambers. there is obstruction of the R ventricular outflow, due to subpulmonic stenosis - which can also be accompanied by *PV stenosis. the aortic valve may be *insufficient and there may be an *atrial septal defect. there is a *R aortic arch present in 25% of cases*. |
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Term
| what happens with a transposition of the great arteries? |
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Definition
| there implies a ventriculoarterial discordance, where the aorta arises from the R ventricle and the pulmonary artery arises from the L ventricle. the valve connections are usually normal. this arises from an abnormal formation of the aortopulmonary septa (aorta arises from the right ventricle and is anterior and to the right of the pulmonary artery) - this separates systemic and pulmonary circulation and is incompatible with life unless there is a shunt somewhere else that allows for mixing of the blood (VSD/ASD/other genetic abnormality) until sx |
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Term
| is transposition of the great arteries (TGA )seen often with VSD? |
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Definition
| yes, and this combination is considered a stable shunt (b/c it is less likely to close) |
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Term
| is is TGA with a patent foramen ovale considered a stable shunt? |
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Definition
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Term
| what happens w/a TGA w/a stable shunt? |
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Definition
| the R ventricle hypertrophies b/c it has to pump blood to the systemic circuit and the L ventricle atrophies b/c it only has to pump blood through the pulm vasculature (heart will look abnormal) |
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Term
| what is the prognosis for TGA pts? |
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Definition
| depends on the mixing of blood/magnitude of hypoxia and the ability of the R ventricle to maintain systemic circulation. w/o sx, most pts die within the first few months of life |
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Term
| what is truncus arteriosus? |
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Definition
| truncus arteriosus results from developmental failure of separation between the embryologic truncus arteriosis into the aora and the pulmonary artery - the result is a single great artery recieving blood from both ventricles w/an underlying VSD and gives rise to the systemic pulmonary and coronary circulations |
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Term
| what is the ultimate effect of truncus arteriosus? why is there a danger of pulmonary HTN? |
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Definition
| there is early cyanosis due to mixing of blood from the RV and LV, but also and increased pulmonary blood flow - leading to the danger of irreversible pulmonary HTN |
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Term
| what is tricuspic atresia? |
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Definition
| occlusion of the TV orifice that results embryologically from unequal division of the AV canal. *the mitral valve is larger than normal |
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Term
| what may accompany tricuspic atresia? |
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Definition
| hypoplasia of the RV (not due to the atresia, but accompanying) |
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Term
| how is circulation maintained with tricuspic atresia? |
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Definition
| circulation is maintained by a R -> L shunt through an ASD or patent foramen ovale. VSD present allows for communication between the LV and the great artery that arises from the hypoplastic R ventricle |
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Term
| what can tricuspic atresia result in? |
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Definition
| R ventricular hypertrophy, R sided heart failure, and passive congestion of the vessls |
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Term
| what is the prognosis for pts with tricuspic atresia? |
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Definition
| cyanosis is present at birth and there is a high mortality in the first weeks of life |
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Term
| what is total anomalous pulmonary venous connection (TAPVC)? |
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Definition
| there are no pulmonary veins joining the L atrium, and the common pulmonary vein fails to develop/becomes atretic - however the primitive systemic venous channels from the lung remain patent. thus in TAPVC, the lung is drained via the L innominate vain or the coronary sinus and either a patent foramen ovale or ASD is present so blood can enter the atrium |
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Term
| how does total anomalous pulmonary venous connection (TAPVC) change the heart's morophology? |
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Definition
| there is hypertrophy of the R atrium, dilation of the R ventricle (engorged with blood and being forced to pump more blood), L atrium is hypoplastic, and the L ventricle starts as normal size, but will become dilated and hypertrophied. cyanosis will be present as well. |
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Term
| what is a common structural anomaly of the aorta? what other syndrome does it have an association with? is it more predominate in one particular sex? |
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Definition
| coarctation of the aorta, which has an association with turners syndrome (45, XO) and is 2x more common in males (if not associated with turners). |
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Term
| what characterizes pts with turner's syndrome? |
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Definition
| short stature, low-set ears, shield chest, cafe au lait spots, L neck, lymphedema, short 4th metacarpals, primary amenorrhea due to accelerated loss of oocytes, *rib notching* due to collateral circulation through intercostal arteries (due to coarctation of the aorta) |
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Term
| what are the 2 forms of coarctation of the aorta? |
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Definition
| 1) infantile form w/tubular hypoplasia of the aortic arch proximal to the PDA (often symptomatic in childhood) or 2) adult form w/ a discrete ridge-like infolding of the aorta |
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Term
| can the degree of aortic luminal encroachment vary in severity? |
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Definition
| yes it can vary from small channel to minimal narrowing - therefore clinical manifestations depend on this luminal narrowing/patency of the ductus arteriosus |
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Term
| how do pts w/coarctation of the aorta w/PDA fare? |
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Definition
| symptoms manifest early in life - infants may not survive the neonatal period w/o surgical intervention |
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Term
| how do pts w/coarctation of the aorta w/o PDA fare? |
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Definition
| most children are asymptomatic and may go unrecognized until adulthood. there will likely be HTN in the upper extremities w/weak pulses and lower BP in the lower extremities. *notching of the ribs occurs due to collateral circulation involving the intercostal and internal mammary arteries and murmurs are often present during *systole |
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Term
| what happens with pulmonary stenosis or atresia? |
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Definition
| the pulmonary valve is stenotic/narrowed (can be mild - severe) and may be isolated or copresent with other anomalies. |
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Term
| if the pulmonary valve is atretic, how might the heart's morphology be affected? |
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Definition
| RVH may develop. if severely atretic, the R ventricle may be hypoplastic/ASD |
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Term
| how will the heart respond to a stenotic pulmonary valve? |
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Definition
| RVH, R sided failure or ok - depending on level of stenosis |
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Term
| when does aortic stenosis/atresia commonly present? what are the 3 kinds? |
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Definition
| at birth. there are three kinds: valvular, subvalvular and supravalvular |
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Term
| what is valvular aortic stenosis? |
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Definition
| the cusps are small, thickened or abnormal in number. severe cases may have hypoplasia of the LV and ascending aorta, and the ductus must be open to allow blood to flow to the aorta and coronary arteries -> almost always fata in the first week of life |
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Term
| what is the sub valvular type of aortic stenosis? |
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Definition
| this represents a thickened ring or collar of dense endocardial fibrous tissue below the level of the cusps |
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Term
| what is the supra-valvular type of aortic stenosis? what is williams syndrome? |
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Definition
| this is an inherited form of aortic dysplasia where the ascending aortic wall is thickened - causing luminal constriction. *williams syndrome is a supravalvular type associated with developmental disorders of other organ systems, the vascular system and *hypercalcemia of infancy |
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Term
| are there genetic issues that can lead to supravalvular aortic stenosis? |
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Definition
| mutations of the elastin gene can cause supravalvular stenosis |
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Term
| can congenital stenosis be tolerated? |
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Definition
| yes, unless very severe - however, the threat of sudden death is present |
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