			Home About us Contact

Arterial Tonometry (arterial + tonometry)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Subclinical vascular alterations in young adults with type 1 diabetes detected by arterial tonometry

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 8 2009
I. Barchetta
Abstract Background Diabetes mellitus is characterized by a very high prevalence of atherosclerotic disease. Aims of this study were to determine arterial compliance parameters in type 1 diabetes (T1D) patients as an expression of early pre-clinical endothelial dysfunction and to evaluate the impact of glucose exposure parameters such as the duration of diabetes and glycosylated haemoglobin (HbA1c) on the risk of developing alterations in vascular compliance. Methods 23 patients with uncomplicated type 1 diabetes (mean age: 32.78 ± 9.06 years, mean disease duration: 10.78 ± 7.51 years, mean HbA1c levels: 7.7 ± 1.9) and 26 age- and sex-matched healthy subjects (mean age: 32.3 ± 8.51 years) were recruited. In these subjects, we evaluated arterial compliance by calibrated tonometry (HDI/PulsewaveÔ CR-2000). Parameters included the following: large artery elasticity (C1), small artery elasticity (C2), systemic vascular resistance (SVR) and total vascular impedance (TVI). Results Patients with longer duration of T1D (>10 years) showed significant alterations in C2 (4.97 ± 2.7 mL/mmHg × 100) and in SVR (1464.67 ± 169.16 dina × s × cm,5) when compared with both healthy individuals (C2: 8.28 ± 2.67 mL/mmHg × 100, p = 0.001; SVR: 1180.58 ± 151.55 dina × s × cm,5, p = 0.01) and patients with recent-onset disease (,10 years) (C2: 10.02 ± 3.6 mL/mmHg × 100, p < 0.001; SVR: 1124.18 ± 178.5 dina × s × cm,5, p < 0.000). Both disease duration and HbA1c independently predicted impaired arterial compliance. Conclusions Young adult T1D patients with no signs of disease complication have detectable vessel wall abnormalities, particularly of small arteries, suggestive of hyperglycaemia-related early endothelial dysfunction. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Effects of deep and superficial experimentally induced acute pain on muscle sympathetic nerve activity in human subjects

THE JOURNAL OF PHYSIOLOGY, Issue 1 2009
A. R. Burton
Human studies conducted more than half a century ago have suggested that superficial pain induces excitatory effects on the sympathetic nervous system, resulting in increases in blood pressure (BP) and heart rate (HR), whereas deep pain is believed to cause vasodepression. To date, no studies have addressed whether deep or superficial pain produces such differential effects on muscle sympathetic nerve activity (MSNA). Using microneurography we recorded spontaneous MSNA from the common peroneal nerve in 13 awake subjects. Continuous blood pressure was recorded by radial arterial tonometry. Deep pain was induced by intramuscular injection of 0.5 ml hypertonic saline (5%) into the tibialis anterior muscle, superficial pain by subcutaneous injection of 0.2 ml hypertonic saline into the overlying skin. Muscle pain, with a mean rating of 4.9 ± 0.8 (s.e.m.) on a 0,10 visual analog scale (VAS) and lasting on average 358 ± 32 s, caused significant increases in MSNA (43.9 ± 10.0%), BP (5.4 ± 1.1%) and HR (7.0 ± 2.0%) , not the expected decreases. Skin pain, rated at 4.9 ± 0.6 and lasting 464 ± 54 s, also caused significant increases in MSNA (38.2 ± 12.8%), BP (5.1 ± 2.1%) and HR (5.6 ± 2.0%). The high-frequency (HF) to low-frequency (LF) ratio of heart rate variability (HRV) increased from 1.54 ± 0.25 to 2.90 ± 0.45 for muscle pain and 2.80 ± 0.52 for skin pain. Despite the different qualities of deep (dull and diffuse) and superficial (burning and well-localized) pain, we conclude that pain originating in muscle and skin does not exert a differential effect on muscle sympathetic nerve activity, both causing an increase in MSNA and an increase in the LF : HF ratio of HRV. Whether this holds true for longer lasting experimental pain remains to be seen. [source]

Elevated augmentation index derived from peripheral arterial tonometry is associated with abnormal ventricular,vascular coupling

CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 5 2010
Kevin S. Heffernan
Summary Background:, Although typically derived from the contour of arterial pressure waveform, augmentation index (AIx) may also be derived from the digital pulse volume waveform using finger plethysmography (peripheral arterial tonometry, PAT). Little is known regarding the physiologic correlates of AIx derived from PAT. In this study, we investigated the relation of PAT-AIx with measures of ventricular,vascular coupling. Methods:, Pulse volume waves were measured via PAT and used to derive AIx. Using 2-dimensional echocardiography, effective arterial elastance index (EaI) was estimated as end-systolic pressure/stroke volume index. Left ventricular (LV) end-systolic elastance index (ELVI) was calculated as end-systolic pressure/end-systolic volume index. Ventricular,vascular coupling ratio was defined as EaI/ELVI. Results:, Given the bi-directional nature of ventricular,vascular uncoupling as measured by echocardiography, patients were separated into three groups: low EaI/ELVI (<0·6, n = 21), optimal EaI/ELVI (mean 0·6,1·2, n = 16) and high EaI/ELVI (>1·2, n = 10). Adjusting for potential confounders (age, mean arterial pressure, height and heart rate), patients with optimal EaI/ELVI had lower AIx (1 ± 4%, P<0·05) compared to those with low EaI/ELVI (13 ± 4%) and high EaI/ELVI (19 ± 5%). Conclusions:, Abnormal ventricular,vascular coupling, arising from either increased effective arterial elastance or increased ventricular elastance, is associated with increased AIx as measured by PAT. Additional research is needed to examine other vascular correlates of PAT-AIx. [source]