Relationship among diastolic intraventricular pressure gradients, relaxation, and preload: impact of age and fitness. - Popovic,Z.B.; Prasad,A.; Garcia,M.J.; Arbab-Zadeh,A.; Borowski,A.; Dijk,E.; Greenberg,N.L.; Levine,B.D.; Thomas,J.D. (Am J Physiol, 2006)