Formation of low-voltage zones on the anterior left atrial wall due to mechanical compression by the ascending aorta.

Deviation of the ascending aorta's course and distention of the NCC appear to be related to the development of LA anterior wall LVZs in the LA-ascending aorta contact area. Mechanical pressure exerted by extracardiac structures on the LA along with the limited thoracic space may contribute to the development of LVZs associated with AF.