Secundum Atrial Septal Defect

Pathophysiology

Atrial septal defect is a common congenital heart defect that results in left to right shunting of blood. The amount of blood shunting across a secundum atrial septal defect is dependent upon the size of the defect and the relative compliances of the left and right ventricles during diastole. Left to right shunting of blood results in excessive blood flow to the right ventricle and pulmonary artery. Right ventricular and right atrial dilatation results. With prolonged dilatation, right ventricular dysfunction and atrial arrhythmias can occur. In addition, long standing pulmonary overcirculation can eventually lead to pulmonary vascular obstructive disease.

Surgical Technique

Closure of secundum atrial septal defect requires cardiopulmonary bypass and aortic cross-clamping. The right atrium is opened, the defect is visualized, and it is closed primarily utilizing running monofilament suture. Especially large secundum atrial septal defects are closed with a patch of pericardium or synthetic material. Aortic cross-clamp time and cardiopulmonary bypass time required to complete repair are short. Patients who undergo this operation should be extubated early in the postoperative course.

Postoperative Considerations

The postoperative course following ASD closure is usually benign. Invasive monitors utilized include arterial and central venous catheters. Intracardiac monitoring catheters and vasoactive infusions are rarely required for hemodynamic management. Length of hospital stay required following surgery averages four to six days.