Atrial septal thickness and area in normal heart specimens and in those with ostium secundum atrial septal defects.

This anatomic study suggests that an understanding of the thickness of the atrial septum should allow better visualization of most portions of the blade-shaped atrial septum during cross-sectional echocardiography, both in normal subjects and in patients with ostium secundum atrial septal defects. The thickness measurements also demonstrate that difficulties in imaging the atrial septum are a function of resolution limits of existing echocardiographic equipment.