Forearm vasoconstriction during dynamic leg exercise in patients with chronic heart failure

Review: Clinical assessment of endothelial function — an update

Endothelial dysfunction precedes clinically detectable vascular disease, suggesting its early detection may allow the targeting of treatment to improve endothelial function and thus inhibit progression of disease.1,2 Although the evidence for a preventive strategy remains circumstantial, there is worldwide interest in the measurement of endothelial function in relation to risk factors and treatment of atherosclerotic vascular disease. Unfortunately, a widely applicable clinical measurement of endothelial function does not yet exist; those that are available remain tools for research. The ideal clinical test of endothelial function should be specific, sensitive and reproducible, as well as simple to perform, painless, and inexpensive. In this review we outline the relative merits and disadvantages of the techniques that are available.

Vasoconstrictive Response in the Vascular Beds of the Non-Exercising Forearm During Leg Exercise in Patients With Mild Chronic Heart Failure

BACKGROUND

Reduced exercise capacity may be related to decreased redistribution of blood flow from the non-exercising tissues to the exercising skeletal muscle in patients with mild chronic heart failure (CHF).

METHODS AND RESULTS

In the present study 14 patients with mild CHF and 10 healthy subjects (N) underwent symptom-limited multistage-ergometer exercise, during which forearm vascular resistance (FVR), cardiac index (CI), systemic vascular resistance index (SVRI), and oxygen uptake (VO(2)) were measured non-invasively using the plethysmograph, impedance, and respiratory gas analysis methods, respectively. The VO(2) and CI at peak exercise were lower (p<0.01 each), and SVRI and FVR at both rest and peak exercise were higher in the CHF group than in N. However, both the percent increase in FVR and percent decrease in SVRI from the resting state to peak exercise were lower in CHF than N, and both of them correlated with not only peak VO(2), but also the corresponding resting value of FVR and SVRI (p<0.01 each).

CONCLUSIONS

Redistribution of blood flow from the non-exercising tissues to the working skeletal muscles, which may participate in exercise capacity, can be blunted in CHF. The decreased vasoconstrictive response in the non-exercising tissues is intimately related to the increased resting vascular tone in CHF.