Diastolic dysfunction refers to an abnormality in the heart's (''i.e.'', left ventricle's) filling during diastole. Diastole is that phase of the cardiac cycle when the heart (i.e. ventricle) is not contracting but is actually relaxed and filling with blood that is being returned to it, either from the body (into right ventricle) or from the lungs (into left ventricle).
In optimal left sided performance of the heart, blood mass loads forward in an unobstructed manner from the lungs, into the pulmonary veins, into the left atrium, through the mitral valve, and finally into the left ventricle. When the left ventricle cannot be normally filled due to deterioration of preload, compliance and A Ratio during diastole, blood regurgitates into the left atrium and, eventually, in a backward gradient into the lungs.
Physiologically this results in a higher than normal [mismatch] pressure gradient of blood within the vessels of the lung. As a result of hydrostatic forces, this pressure mismatch leads to leaking of fluid (i.e. transudate) from the pulmonary blood vessels into the air-spaces (alveoli) of the lungs. The result is pulmonary edema, a condition characterized by difficulty breathing, inadequate oxygenation of blood, and, if severe and untreated, death.
Pulmonary edema developed as a result of diastolic dysfunction is not fully imparted by failing pump function of the left ventricle. Indeed, it may result from the left ventricle's inability to readily accept blood trying to enter it from the left atrium.
This article is licensed under the Creative Commons Attribution-ShareAlike License.
It uses material from the Wikipedia article on
All material adapted used from Wikipedia is available under the terms of the
Creative Commons Attribution-ShareAlike License.
Wikipedia® itself is a registered trademark of the Wikimedia Foundation, Inc.