It is the commonest congenital heart diseases in adults.

TYPES

Ostium secundum type 75%

Commonest. It is due to defective formation of seotum secundum.

Ostium primum type (20%)

Rare. This is due to defective formation of septum primum and is associated with cushion defect.

Sinus venosus type (5%).

Here the defect id in the upper part of the septum and it is associated with anomalous connection connection of pulmonary veins with either superior vena cava or right atrium.

ATRIAL SEPTAL DEFECT(ASD)

CHANGES

ATRIAL SEPTAL DEFECT (ASD)

Due to pressure gradient and more compliance the existent defect in the atrial septum will cause shunting of blood from left to right atrium and then to the right ventricle and pulmonary trunk causing hypertrophy and dilation of the structures.

In course of the due to increased pressure on the right side of the heart reversal of the shunt may rarely take place (Eisenmeneger’s syndrome).

Sometime mitral stenosis may be associated with ASD which is called lutembacher’s syndrome and skeletal deformity called Holt-Oram syndrome.

FEATURES:

1. COmmon in female. Usually asymptomatic until middle age.
2. General development is poor with thin build (Gracile habitus). High arch palate and arachnodactyly with accessory phalanx and difficulty in apposition of thumb may be seen, called Holt-Oram syndrome.
3. Seldom any symptom before 3^rd or 4^th

Symptoms when present include dyspnoea, palpitation , rarely cardiac failure,fatigue. Left atrialization of jugular venous pressure (I. e. a wave =V wave)

4. TIA or CVA due to paradoxical embolism.
5. Right ventricular hypertrophy with hyperdynamic right ventricular impulse.
6. An ejection systolic murmur Grade I-III /VI and sometimes a systolic thrill over pulmonary area. A dilated pulmonary truncal pulsation over left second space.

CYANOSIS

When cyanosis appears it indicates shunt  reversal.

7. Wide and fixed splitting of the second heart sound with accentuated P2 over left 2^nd and 3^rd
8. Functional mid-diastolic flow murmur on the tricuspid area appears with right ventricular failure.
9. Fluoroscopy reveals hilar dance and X-ray shows prominent pulmonary artery and enlarged right ventricle, small aortic knob.
10. Echocardiography with saline contrast and Doppler flow can show right ventricular volume overload with large right ventricle and atrium and the defect itself.
11. ECG show incomplete/complete right bundle branch block, right axis shift and RV hypertrophy. Left axis deviation is seen in ostium primum defect.
12. Cardiac catheterisation is required for a definite diagnosis to evaluate the degree of shunt and associated defect
    

    ATRIAL SEPTAL DEFECT(ASD)

    s.