Evaluation of the microcirculation in hypertension and cardiovascular disease

Abstract

The ability to investigate the microvascular structure and function is important in improving our understanding of pathophysiological processes in hypertension and related cardiovascular disease. A range of techniques are available or emerging for investigating different aspects of the microcirculation in animals and humans. Techniques such as experimental intravital microscopy and clinical intravital microscopy (e.g. orthogonal polarization spectral imaging) allow visualization at the level of single microvessels. Venous occlusion plethysmography can be used to measure blood flow in organs, and laser Doppler flowmetry to measure red cell flux in small areas of tissue. Positron emission tomography, myocardial contrast echocardiography, and magnetic resonance imaging provide three-dimensional imaging of local blood flow. The current and potential clinical usefulness of these different techniques is evaluated. The technical quality and availability for clinical use of some of the techniques should improve dramatically during the next few years. 'Molecular imaging'-the combination of these techniques with genetic, molecular, and computational approaches-offers great potential for use in research and in diagnosis and the monitoring of disease progression or the results of therapy. Closer attention to the microcirculation will ultimately improve the treatment and prevention of many of the most important forms of cardiovascular disease.

Accessing to arteriovenous blood flow dynamics response using combined laser speckle contrast imaging and skin optical clearing

“…According to Rayleigh's criterion [61], the speckle contrast value of vessel area is less than or equal to 2 8/π times that of the non-vessel area, the vessel can be distinguished. The smaller the distinguished diameter of blood vessel is, the higher the resolution of images.…”

“…Cutaneous microcirculation, as an accessible and representative vascular bed [1], has been widely applied to assess microcirculatory function and dysfunction, pathology-induced vascular dysfunction, including hypertension [2], diabetes [3] and some other peripheral vascular diseases [4]. Thus, various imaging techniques have been widely developed, e.g.…”

Transdermal iontophoresis as an in-vivo technique for studying microvascular physiology

“…The method that probably had the most impact on our current understanding of the basic vascular pharmacology and physiological functions of the microvasculature is the in vitro preparation of isolated vessels (Angus and Wright, 2000;Struijker-Boudier et al, 2007). The vessels, which are either harvested from animals or of human origin, are typically cut into segments of a few millimeters long and are mounted on hooks or sutured to two concentric pipettes and are directly coupled to a force transducer allowing wall force to be measured.…”

Is capillary rarefaction an independent risk marker for cardiovascular disease in South Asians?

“…1 There is increasing evidence of the imperative involvement of the microcirculation (that is, arteries, arterioles, capillaries and venules) in many CVD conditions and in particular hypertension. 2 We have previously reported reduced capillary density (that is, rarefaction) in individuals with essential hypertension, pre-hypertension, in normotensive subjects at high risk of developing hypertension 3,4 and in patients with angina pectoris. 5 The aim of this study was to find out whether capillary rarefaction is a significant risk factor in South Asian individuals by comparing their skin capillary density with matched Caucasian subjects.…”