 |
| Atrial septal defect |
Atrial septal defect
Asd is an abnormal communication between two atria . Congenital heart disease wth lt to rt shunt*TYPES
1. Ostium secondum type - located at fossa ovalis.Ten times more common
2. Ostium primum type - inf. to fossa ovalis
*HEMODYNAMICS
-There is leak of oxygenated blood from lt to rt atrium
- pressure diff. betwn 2 atria is small hence shunt is silent on auscultation
-rt. atrium enlarges in size to accomodate extra volume of blood from left atrium
-large volume of blood passes through normal sized tricuspid valve resulting in delayed diastolic murmur audible at lower lt. sternal border.
-pulm. ejection murmur. Pulmn. valve closes late resulting in delayed P2 .Second sound is widely split & fixed P2 is also accentuated
-cardiac apex formed by rt. ventricle
-lung fields are plethoric
*CLINICAL Features
-most asyptomatic
-mild effort intolerance
-frequent chest infectios
- Physical examination
1 parasternal impulse
2 cardiac enlargement
3 first sound - normal or may be enlarged
4 second sound - widely split & fixed wth P2 accentuated
5 ejection systolic murmur at 2nd & 3rd lt interspace
6 shunt murmur abs
7 flow murmur (a) tricuspid - delayed diastolic (b) pulmonary - ejection systolic
*INVESTIGATIONS
1 ECG
1 ostium secundum asd - rt. axis deviation & rt. Ventricular hypertrophy
2 ostium primum asd - lt. Axis deviation beyond -30 degree
2 CXR
mild to moderate cardiomegaly ,rt. Atrial & yentricular enlargement ,prominent main pulmonary artery ,small aortic shadow & plethoric lung fields
3 ECHOCARDIOGRAM
increased size of rt. ventricle
*COMPLICATIONS
1. Pulmn. arterial Htn
*Rx
-size of lt. to rt. shunt directly proportional to intensity of the two murmur & heart size
- Rx chest infection
-prophylaxis for IE
-definitive cure by operation. Most surgeon prefers heart lung bypass. Ideal age for operations 2-5yrs.
EmoticonEmoticon