RESUMO
Both the morphology and the functions of the interatrial septum in different clinical situations have been addressed only in a few studies, where the attention has been focused particularly on its congenital abnormalities. Our purpose was to study whether the changes of thickness and thinning of the interatrial septum may be related to the age, left atrial dimension and left ventricular functions. So we studied these changes using the transesophageal echocardiography in [60] patients of four groups of cardiovascular discuses. These groups were: Group I: Ischemic heart disease 20 patients. Group II: Dilated cardiomyopathy 20 patients. Group III: Hypertension with stroke 8 patients. Group IV: Corpulmonale 12 patients. All the patients were subjected to thorough clinical examination, 12 leads resting electrocardiography, chest X-ray postero-anterior view and echocardiography in which we made both transthoracic and esophageal approach for each patients. The interatrial septum thinning was calculated as the difference between the thickness of the IAS at atrial systolic phase and the thickness of the IAS at end-ventricular systolic phase. The value was expressed also as percentage of thinning at the end of ventricylar systolic phase. The IAS thickness increases with the age while there is no significant increase in thinning and thinning percentage. The IAS thickness increases in patients of left ventricular dysfunction e.g. [dilated cardiomyopathy, ischemic heart diseases, and hypertensive patients] also it increases in patients of corpulmonale. There is a negative correlation between the IAS thickness and the left atrial dimension, but there is a positive correlation between the IAS thinning and IAS thinning percentage with the left atrial dimension. Patients with prolonged deceleration time of E and isovolumic relaxation time and decreased E/A with or without lower ejection fraction and fractional shortening had less IAS thinning%. On the other hand, patients with shorter deceleration time of E and isovolumic relaxation time and increased E/A with or without lower ejection fraction and fractional shortening had a comparable IAS thinning%.