Location:
upper portion of right side of heart consisting of the sinus venosus and the right atrial appendage; contains the sinoatrial node

Function:
returns deoxygenated blood from the body to the right ventricle

Importance in cardiovascular diseases:
atrial arrhythmias; dilated in tricuspid stenosis and tricuspid regurgitation; congenital defects (e.g., patent foramen ovale, atrial septum defects)

Importance in device delivery:
alternate and dual-site pacing to prevent atrial fibrillation