[Post operative embolism and left atrial enlargement in the old-aged ASD (atrial septal defect) patients]

As the operation risk of ASD is little today, the unexpected postoperative complication such as embolism is a miserable concern. We experienced two cases of embolism, which were cerebral infarction, in old-aged patients after ASD correction. It has been reported that low cardiac function, atrial fibrillation and foreign body in the left atrium should be risk factors of the embolism after ASD correction. However, blood stasis in the left atrium due to its enlargement may be an essential risk factor of the embolism. Accordingly we evaluated the left atrial volume in 87 ASD patients without complicated cardiac disorder. There was a significant correlation between the age (X) and left atrial volume index (Y). (Y = 16.5 + 1.1X, r = 0.668, p < 0.001). Left atrial volume index in our two cases of cerebral infarction indicated 171.7, 190.8 ml/m2 respectively. The former case had sinus rhythm and its defect was directly closed, and the latter had atrial fibrillation and its defect was closed with teflon patch. In addition pulmonary artery pressure and cardiothoracic ratio correlated with left atrial volume index significantly. Although some investigators reported that pulmonary hypertension and cardiomegaly were the risk factors of embolism, the left atrial enlargement by aging was thought to be the main risk factor. Thus, we concluded that anticoagulant therapy was necessary for the ASD patients with marked left atrial enlargement.