In the article by Lam et al, “Cardiac Structure and Ventricular--Vascular Function in Persons With Heart Failure and Preserved Ejection Fraction From Olmsted County, Minnesota,” which appeared in the April 17, 2007, issue of the journal (Circulation. 2007;115:1982--1990), the following corrections should be made. On page 1982, the β symbol in the equation should be superscripted so that the equation would read, “EDP=αEDV^β.” This change should also be made to the same equation in the legend to Figure 3 on page 1987. These errors have been corrected in the current online version of the article. The publisher regrets these errors.