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 Atrial Septal DefectASD
 
 
 
 General Considerations 
  Atrial septal defects       (ASD) represent 10-15% of congenital cardiac abnormalities
      
        Sinus venosus  type of ASD accounts for 10% of ASDs and only 1% of  all congenital heart lesions   
  
    
      | Four Major    Types of ASD |  
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        Most common is ostium secundum (60%) located at    fossa ovalis |  
      | High association with prolapse of the mitral valve |  
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        Ostium primum type is usually part of an endocardial cushion defect |  
      | It tends to act like a VSD physiologically |  
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        Sinus venosus type lies high in the interatrial septum |  
      | 90% association of anomalous drainage of R upper    pulmonary vein with SVC or Right atrium |  
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        Most rare type    is posteroinferior ASD |  
      | Associated with absence of the coronary sinus and a    left SVC emptying into LA |    
  2:1 ratio of females  to malesThe most  frequent congenital heart lesion initially diagnosed as an adultSinus venosus type       occurs high in the inter-atrial septum, in contiguity with the superior       vena cavaInvariably associated       with anomalous pulmonary venous drainage of the right upper pulmonary vein       into the SVC (partial anomalous pulmonary venous return-PAPVR) Clinical Findings 
  Usually asymptomatic       in infancyCardiac murmurEasy fatigabilityDyspneaIf uncorrected, arrhythmias,       congestive heart failure and eventually pulmonary hypertension in       adulthood Imaging Findings 
  Chest radiographs may       be normal or have an enlarged main pulmonary artery and  increased pulmonary vasculatureEchocardiography will       show ASD and most pulmonary vein connectionsMRI will show ASD and       outline venous anatomy
      
        Septal defect  high in the inter-atrial septum contiguous with superior vena cavaPosterior to  location of fossa ovalis Differential Diagnosis 
  Other forms of atrial       septal defectPartial anomalous       pulmonary venous return without ASD Treatment 
  Sinus venosus ASDs do not close spontaneouslySurgical repair in       the first two decades of life
      
        A patch of  either synthetic material or pericardium redirects blood flow from the right  superior pulmonary vein into the left atrium.  Complications 
  Congestive heart       failurePulmonary arterial       hypertension Prognosis 
  Excellent prognosis       if treated 
  
   
 
 Sinus Venosus Atrial Septal Defect with Partial Anomalous Pulmonary Venous Return. Top: There is a large atrial septal defect (red arrow) connecting the left atrium (LA) and right atrium (RA) at the level of the superior vena cava. Bottom: Right pulmonary veins drain directly into the superior vena cava (S) instead of the normal return to the left atrium.For these same photos without the arrows, click here and here
   
 Atrial Septal Defect. There is a large atrial main pulmonary artery because of the increased shunt from left to right. The pulmonary vasculature is prominent throughout the lungs due to increased flow. For more information, click on the link if you see this icon
 
 Atrial  Septal Defect, Sinus Venosus. eMedicine. GM Satou 
  
 
 
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