The preliminary cause of death for Sen. Lindsey Graham (R-S.C.) has been identified as an aortic dissection due to arteriosclerotic cardiovascular disease, according to a D.C. medical examiner's report. Aortic dissections occur when the inner layer of the aorta tears, a condition that is rare, affecting an estimated five to 30 people per 1 million, according to the American Heart Association. The condition is most common in men in their 60s and 70s, and Graham was 71. Dr. Neel Mansukhani, a vascular surgery expert, described it as "similar to paint peeling off a wall," with consequences depending on the tear's location.