Extracellular volume fraction correlates with myocardial stiffness and allows for differentiation between impaired active relaxation and passive stiffness in heart failure with preserved ejection fraction. Issue 1 (December 2016) - Rommel, Karl-Philipp; Roeder, Maximilian; Stiermaier, Thomas; Latuscynski, Konrad; Oberueck, Christian; Blazek, Stephan; Sandri, Marcus; Luecke, Christian; Gutberlet, Matthias; Schuler, Gerhard; Lurz, Philipp