OverviewThe pericardium is a thin double-layered sac which encloses the heart. Fluid is contained within the layers and lubricates the constantly rubbing surfaces.
Update Date 2/24/2016
Updated by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.