This Figure shows the effect of maintaining sinus rhythm on atrial volume after cardioversion. [30] For patients who revert to AFib after cardioversion (the dark blue bars in both left and right atrium), there is no change in atrial volume before and after cardioversion.  However, for patients who remain in sinus rhythm after cardioversion (the light blue bars in both left and right atrium), atrial volume is decreased at 6 months after successful cardioversion.  Nevertheless, however, even if sinus rhythm is maintained, atrial volume does not reduce to normal (not shown in the Figure), and the risk persists, because atrial size and function and endothelial function are not normal, despite sinus rhythm.

Reiffel JA. Am J Med 2013; 126: 00-00.