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.
1. Cats can sleep as much as 16 hours a day, and older cats spend even more time at rest â as much as 20 hours a day. That sleeping habit is a result of the catâs evolution, nutritional habits, and physiology.