Atrial Septal Defect (ASD)
Atrial septal defect (ASD)
In an atrial septal defect (ASD), a hole in the atrial septum is oxygen-rich blood that is flowing from LA to RV. The RA, RV and ultimately the lungs, therefore there is more volume of blood to process. ASD is a volume load on the RV.
[[Image: |Video]]
| ASD is to be divided into four types: | ||
| Type | Name | Location |
|---|---|---|
| ASD type I | Ostium primum defect | In the basal septum t.p.v. atrioventricular ventricular transition |
| ASD type II | Ostium secundum defect | In the middle of the atrial septum, the fossa ovalis area. |
| ASD type III | Sinus venosus defect | At the entrance of both the VCS and the VCI |
| Coronary sinus defect | Coronary sinus defect | Compound coronary sinus with LA. |
ASD can manifest at any age . An ASD comes in 9 % of all congenital heart defects , but for the most common congenital heart disease that often only reflected ( 30 % ) in adulthood .
| Most common ASD | |
| ASD II | 70 % |
| ASD I | 15 % |
| Sinus venosus defect 1 | 5 % |
| Coronary sinus defect | Rare |
Patent Foramen Ovale (PFO)
A patent foramen ovale , abbreviated to PFO , has a functional defect in the atrial septum, in contrast to an ASD that has an anatomical defect. The septum primum and septum secundum develop from different edges in the embryonic atria . However , the septum secundum does not form a closed portion , there always remains an opening between the two septa. At birth, the inter- atrial pressure is changed and to be pressed against each other , the two septa . In 15-35 % of the population, there still remains a small opening . A PFO is in fact an incomplete fusion of the septum primum and septum secundum .
A PFO is involved with a number of other pathologies such as cerebrovascular accident ( CVA ) , Transient Ischemic Attack ( TIA ) , Caisson Disease ( Decompression sickness among divers ) , Platypneu - orthodeoxiesyndroom and Migraine . There is a direct relationship between the size of the shunt and the risk of stroke .
A PFO can be demonstrated with the aid of contrast by means of a saline solution . There is a PFO if within three cardiac cycles to see a crossing from right to left after administration of contrast.
The number of bubbles in one frame can be categorized in size of opening:
| Size of PFO | |
| Narrow opening | < 10 contrast bubbles in LA |
| Excessive opening | 10-20 contrast bubbles in LA |
| Grand opening | > 20 contrast bubbles in LA |
| Video |
| Crossing contrast to PFO [1] |
|---|
Echocardiographic points
| Considerations | |
| Localization of defect | Color doppler + possible contrast. Where in IAS? |
| Instructions for volume overload | Dimensions RF + RA. Question of dilation? |
| Evidence of pulmonary hypertension | SPAP. See high pressures? |
Click here for Qp / Qs calculation.
Example of ASD Large ASD type II contrast crossing at ASD type II ASD closure
Closure of ASD occurs with Closure Device. Endocardial tissue grows over the device over .
Source : EC Cheriex , " Left atrium and investigated ," Hamer / Pieper , ' Practical echocardiography , (2006 ) , 1st edition 2nd edition, Wood , Bohn Stafleu of Loghum , p.42 -53 .