• Diastolic function: ability of the left ventricle to sufficiently fill to produce the needed stroke volume in systole at normal diastolic left ventricular and left atrial pressures.
• Determined by active left ventricular relaxation (which can be quantitated by the pressure decay constant τ), passive left ventricular material properties, and other factors
• Diastolic pressure-volume relations can be characterized physiologically by pressure-volume loops and the derived instantaneous chamber stiffness (Δ pressure / Δ volume)
• DD: characterized by elevated left sided diastolic pressures:
  • > 12 mmHg mean pulmonary capillary wedge pressure (≈ mean left atrial pressure);
  • > 16 mmHg LV end-diastolic pressure
• Morphological correlates of DD are left ventricular wall thickness increase and overall hypertrophy, and increased left atrial volume
• Functional correlates of DD are decreased left atrial function, alterated transmitral and pulmonary venous flow patterns, low e’, pulmonary hypertension, and others