Factors influencing the diastolic pressure-volume relation of the cardiac ventricles.

The diastolic pressure-volume relationship of either ventricle is a direct measure of the properties of its chamber. While this relation is, to a large extent, determined by the myocardium and its mechanical properties, there are a number of physiological factors that are also capable of influencing the diastolic pressure-volume-relation. This review examines our current understanding of the importance of a number of these factors with respect to the diastolic properties of the chamber. The factors discussed are heart rate, arterial pressure, coronary perfusion pressure, the pericardium, and the mechanical interplay between ventricles. The influence of heart rate, arterial pressure, and coronary perfusion pressure can be considered as minor provided they remain within their normal physiological range. On the other hand, the diastolic pressure-volume relation is highly dependent on the volume in the other ventricle, particularly in the presence of the pericardium. An awareness and understanding of the interrelationship between these factors and the diastolic pressure-volume relation is essential when evaluating the properties of the chamber and when such pressure-volume data are used to estimate the mechanical properties of the myocardium.