Peripheral Muscle Microcirculatory Alterations in Patients With Pulmonary Arterial Hypertension: A Pilot Study

Abstract

The PAH subjects had substantial impairments of peripheral muscle microcirculation, decreased tissue O(2) saturation (possibly due to hypoxemia), slower reactive hyperemia time, (possibly due to endothelium dysfunction), and peripheral systemic vasoconstriction. Acute hyperoxic breathing improved resting tissue O(2) saturation (an expression of higher oxygen delivery) and decreased the oxygen consumption rate and reactive hyperemia time during reperfusion, possibly due to increased oxidative stress and evoked vasoconstriction.

Sublingual Microcirculation in Pulmonary Arterial Hypertension

“…The biological mechanisms behind the SL microcirculatory abnormalities in PAH are not clear and need further investigation. Potential factors associated with systemic endothelial dysfunction in PAH include a reduction in nitric oxide synthesis, overexpression of endothelin in systemic endothelial cells (38,39), modification of the serotonin pathways (40), increase in circulating inflammatory chemokines and cytokines (41), hypoxemia (42), sympathetic overactivity (43), or alterations of cellular bioenergetics (44).…”

Pulmonary arterial hypertension-related myopathy: An overview of current data and future perspectives

“…Skeletal muscle microcirculation of PAH patients appears to be impaired as shown by low O 2 saturation at the tissue level, measured by a near-infrared spectroscopy technique [38]. Moreover, abnormalities of the microvascular O 2 delivery-toutilization rate, which in turn slow the rate of adaptation of aerobic metabolism, were found in woman with PAH [39].…”

Muscle microcirculation alterations and relation to dipping status in newly diagnosed untreated patients with arterial hypertension—A pilot study

“…The EF (%/min) was evaluated by the first degree slope of StO 2 increase after the release of the brachial artery occlusion. We also estimated THI which represents the amount of total hemoglobin within the measured volume represented in au and the restoration of tissue oxygenation by the RHT (minute), which is the time needed for StO 2 to reach its baseline values after the removal of the ischemic stimulus …”

“…Vascular reactivity tests are widely used in the assessment of EF and cardiovascular risk estimation. NIRS combined with VOT is a validated, well described, and easily applicable at the bed‐side technique to evaluate peripheral tissue microcirculation in humans . The technique evaluates the peripheral tissue oxygen utilization and restoration of tissue oxygenation after an ischemic stimulus, which also depends on the integrity and functionality of the vascular endothelium.…”