Adaptive changes of the vascular system in heart failure. Potential role of impaired endothelial vasomotor function.

An abnormality of myocardial cell function is the primary pathophysiologic basis of heart failure. However, complex alterations of the whole circulatory system are also pathophysiologically important. At an early stage these alterations represent adaptive mechanisms which compensate for the impaired cardiac output. Later on, however, they induce a vicious circle which leads to a further progression of heart failure. The circulatory alterations are due to changes of the activity of neuroendocrine, hormonal and local autocrineparacrine factors. The latter most likely include alterations of the endothelial vasomotor function. The potential significance of impaired endothelial NO-release in heart failure and present clinical evidence for such a mechanism are discussed.