It is generally believed that diastolic heart failure represents a problem with compliance and relaxation of the ventricle. One possible explanation for this is thought to be an abnormality of collagen structure in the myocardium. There are data from hypertensive populations as well as from hypertensive experimental models indicating an abnormal fibrotic process in patients with hypertensive heart disease. However, there are a few data on this potential aetiological explanation for diastolic heart failure.