| ATR | irritable as if suffering from indigestion |
|---|---|
| ATR | an abnormal condition in which a normal opening or tube in the body (as the urethra) is closed or absent |
| ATR | (anatomy) of or relating to a cavity or chamber in the body (especially one of the upper chambers of the heart) |
| ATR | the branch of the coronary artery that supplies the muscles of the atria |
| ATR | a small conical pouch projecting from the upper anterior part of each atrium of the heart |
| ATR | fibrillation of the muscles of the atria of the heart |
| ATR | an abnormal opening between the left and right atria of the heart |
| ATR | type genus of the Atrichornithidae |
| ATR | scrubbirds |
| ATR | relating to or affecting the atria and ventricles of the heart |
| ATR | recurrent sudden attacks of unconsciousness caused by impaired conduction of the impulse that regulates the heartbeat |
| ATR | a bundle of modified heart muscle that transmits the cardiac impulse from the atrioventricular node to the ventricles causing them to contract |