HRS Photo 1 (IMAGE) Intermountain Medical Center Caption Researchers have identified that enlargement of the left atrium of the heart is linked to abnormal activity of molecules that are associated with adverse changes in the heart's size, shape, structure, and function -- conditions that can lead to atrial fibrillation and death. Credit Intermountain Medical Center Heart Institute. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.