Pathophysiology.- Molecular Mechanisms of Diastolic Dysfunction.- Pathophysiologic Aspects of Myocardial Relaxation and End-Diastolic Stiffness of Cardiac Ventricles.- Ventricular Interaction via the Septum and Pericardium.- Role of the Left Atrium.- Role of Neurohormones and Peripheral Vasculature.- Filling Velocities as Markers of Diastolic Function.- Myocardial Velocities as Markers of Diastolic Function.- Diastolic Versus Systolic Heart Failure.- Diagnosis of Diastolic Heart Failure.- Invasive Evaluation of Diastolic Left Ventricular Dysfunction.- Echocardiographic Assessment of Diastolic Function and Diagnosis of Diastolic Heart Failure.- Magnetic Resonance Imaging.- Natriuretic Peptides in the Diagnosis of Diastolic Heart Failure.- Noninvasive Estimation of Left Ventricular Filling Pressures.- Epidemiology, Prognosis, and Treatment.- Epidemiology of Diastolic Heart Failure.- Prognosis in Diastolic Heart Failure.- Treatment of Diastolic Heart Failure.- Specific Disease-Related Problems in Diastolic Heart Failure.- Coronary Artery Disease and Diastolic Left Ventricular Dysfunction.- Hypertension and Diastolic Function.- Diastolic Disturbances in Diabetes Mellitus.- Hypertrophic Cardiomyopathy.- Constrictive Pericarditis and Restrictive Cardiomyopathy.- Summary.