Phenotyping the microcirculation.

The role of the microcirculation is increasingly being recognized in the pathophysiology of cardiovascular disease. The microcirculation is a major site of damage in most target organs of cardiovascular disease, such as the heart, brain, and kidney. Both functional and structural alterations in the small arteries, arterioles, and capillaries are the basis of target organ damage. Furthermore, the microcirculation is the major site of control of vascular resistance. This makes it a central player in the etiopathogenesis of diseases characterized by an increased vascular resistance, such as hypertension. Detailed mechanistic studies in both humans and animal models of cardiovascular disease have revealed the nature of microcirculatory dysfunction. Large-scale epidemiological studies in the last 2 decades have identified the associations among deranged microvascular perfusion, structure, target organ damage, and subsequent cardiovascular disease. Major technological developments now allow study of the microcirculation both in mechanistic and epidemiological studies. The purpose of this Brief Review is to provide a critical appraisal of these developments and their particular impact on hypertension research.