Assessment of macrovascular endothelial function using pulse wave analysis and its association with microvascular reactivity in healthy subjects.

BACKGROUND: Pulse wave analysis (PWA) and laser Doppler fluximetry (LDF) are non-invasive methods of assessing macrovascular endothelial function and microvascular reactivity respectively. The aim of this study was to assess the correlation between macrovascular endothelial function assessed by PWA and microvascular reactivity assessed by LDF. METHOD: 297 healthy and non-smoking subjects (159 females, mean age (±SD) 23.56 ± 4.54 years) underwent microvascular reactivity assessment using LDF followed by macrovascular endothelial function assessments using PWA. RESULTS: Pearson's correlation showed no correlation between macrovascular endothelial function and microvascular reactivity (r = -0.10, P = 0.12). CONCLUSION: There was no significant correlation between macrovascular endothelial function assessed by PWA and microvascular reactivity assessed by LDF in healthy subjects.

Arterial stiffness during acute and recovery phases of children with rheumatic fever.

Acute rheumatic fever (ARF) is associated with systemic inflammation and arterial stiffness during the acute stage. It has not been reported if arterial stiffness remains after recovery. The aim of this study was to determine the arterial stiffness during acute stage and 6 months after recovery from ARF. Arterial stiffness was assessed by carotid femoral pulse wave velocity (PWV) in 23 ARF patients during the acute stage of ARF and 6 months later. Simultaneously, erythrocyte sedimentation rate (ESR) and other anthropometric measurements were taken during both stages. There was a significant reduction in PWV; 6.5 (6.0, 7.45) m/s to 5.9 (5.38, 6.48) m/s, p=0.003 6 months after the acute stage of ARF. Similarly, ESR was also significantly reduced from 92.0 (37.5, 110.50) mm/hr to 7.0 (5.0, 16.0) mm/hr, p=0.001. In conclusion, arterial stiffness improved 6 months after the acute stage with routine aspirin treatment; this correlates well with the reduction in systemic inflammation.

Method optimization to assess endothelial function in females-duration of glyceryl trinitrate effect.

Pulse-wave analysis (PWA) combined with pharmacological challenges has recently been used as a method to measure endothelial function. This involved administration of glyceryl trinitrate (GTN), followed by salbutamol as endothelium-independent and -dependent vasodilators, respectively. The duration of GTN effect needs to be established before the administration of salbutamol. Baseline augmentation index (AIx) and pulse-wave velocity (PWV) measurements were taken in 11 healthy female subjects (mean age 23.27 +/- 3.66 years). Sublingual GTN 0.5 mg was administered for 3 min, followed by AIx and PWV measurements every 5 min till 20 min and then every 10 min until 40 min post-GTN. Maximum change in AIx post-GTN was at 3 min with a mean change from the baseline of -17.86% +/- 4.40% (p < 0.001). There were no significant changes noted after 30 and 40 min with mean change being -0.82% +/- 2.61% and 0.14% +/- 3.20%, respectively (p > 0.05). Significant changes in PWV were noted at 5 and 10 min with the mean change of -0.33 +/- 0.36 m/s and -0.33 +/- 0.35 m/s, respectively (p = 0.01). There were no further changes noted at 15 min and thereafter (p > 0.05). A duration of at least 30 min after GTN is required for AIx and PWV values to reach their baseline. Thus, the administration of salbutamol should be given only after 30 min of sublingual GTN for the assessment of endothelial function.