Atrial septal defect. (Redirected from Patent foramen ovale) Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atria (upper chambers) of the heart. Normally, the atria are separated by a dividing wall, the interatrial septum.
If you think your cat is sleeping a lot, youâre not off base. Cats tend to sleep in some form or another for anywhere from 16 to 20 hours a day.
Check out the five animals that sleep the most, on average. 1  Brown Bat: 19.9 hours per day. 2  Giant Armadillo: 18.1 hours per day.  North American Opossum: 18 hours per day.