Peripheral Arterial Volume Research Articles

Reproducibility of a New Method to Assess Endothelial Function According to Peripheral Arterial Volume

Background: The assessment of endothelial function is crucial for understanding cardiovascular disease progression. Reliable, convenient non-invasive methods are necessary for evaluating endothelial function. Peripheral arterial volume (PAV), measured at the fingertip, is a novel approach for which limited reproducibility data are available. Hence, this study was aimed at evaluating PAV measurement reproducibility in a clinical setting. Method: A total of 152 consecutive patients (average age 55.8 ± 12.3 years, 83 men) with chest pain were included in the study. PAV tests were conducted on the same day. The amplitude ratio before and after application of pressure, along with the reference ratio, were recorded to calculate the PAV. Medical baseline data for these patients were gathered from the hospital’s records. Result: On test days, the PAV results from repeated measurements were 1.15 ± 0.33 and 1.15 ± 0.31 (P = 0.99), indicating no significant difference between measurements in all participants. The mean difference was 0.00 ± 0.32, thus indicating no systematic errors, and the intraclass correlation coefficient was 0.66. Furthermore, age, sex, and BMI did not influence PAV reproducibility. Conclusion: PAV measurement is feasible and exhibited excellent reproducibility among all enrolled patients. As a novel fingertip measurement, PAV has promise as a convenient and accurate method for assessing endothelial function in adults.

GW29-e0554 Reproducibility of a new method to assess endothelial function by peripheral arterial volume

GW29-e0554 Reproducibility of a new method to assess endothelial function by peripheral arterial volume

A13635 The novel measurement of peripheral arterial volume improves the predictive value of coronary artery disease in a high-risk population

A13635 The novel measurement of peripheral arterial volume improves the predictive value of coronary artery disease in a high-risk population

GW29-e0553 The novel measurement of endothelial function by peripheral arterial volume improves the predictive value of coronary artery

GW29-e0553 The novel measurement of endothelial function by peripheral arterial volume improves the predictive value of coronary artery

A new method for the assessment of endothelial function with peripheral arterial volume

BackgroundCurrently, many methodological approaches have been developed to assess peripheral endothelial function. However, a development of the noninvasive and automated technique for routinely assessing endothelial function is still required. We evaluated the potential value of a new method to measure peripheral endothelial function with reactive hyperemia peripheral arterial volume (RH-PAV) in patients with chest pain.MethodsWe used a novel oximeter-like probe to detect the peripheral arterial volume (PAV) of the finger and compared it with brachial flow-mediated dilation (FMD) performed in 93 consecutive patients with chest pain. The RH-PAV index was defined as the ratio of the digital pulse volume during reactive hyperemia relative to the baseline.ResultsNinety-three patients (53 men, 58 ± 5 years) completed the study, and 53 patients demonstrated coronary artery disease (CAD) following scheduled coronary angiography. There was a moderate linear relationship between PAV and FMD (r = 0.69, p < 0.01). Similar to FMD, PAV was more impaired in patients who have more cardiovascular risk factors (CRFs). The subjects with CAD had lower PAV and FMD, compared with those without CAD (1.05 ± 0.23 VS. 1.41 ± 0.37, p < 0.01; 6.7% ± 2.9% VS. 10.4% ± 2.9%, p < 0.01, respectively), and the relationships between FMD and PAV were also significant in both CAD (r = 0.54, p < 0.01) and non-CAD (r = 0.62, p < 0.01) patients.ConclusionsEndothelial function of digital artery assessed with the novel PAV method demonstrated a profile similar to that of brachial artery measured with FMD. The hyperemia PAV was decreased by factors which were considered to impair endothelial function, suggesting that PAV has the potential to be a novel method to study endothelial function.

A NOVEL METHOD FOR ENDOTHELIAL FUNCTION ASSESSMENT WITH FINGER ARTERIAL PULSE VOLUME

Currently, several methods have been developed to assess peripheral endothelial function. We evaluated the potential value of reactive hyperemia peripheral arterial volume (RH-PAV) in patients with stable angina. We used a novel oximeter-like probe to detect the peripheral arterial volume (PAV) of the finger, and compared with brachial flow-mediated dilation (FMD) performed simultaneously in 93 consecutive patients with stable angina. The hyperemia PAV index was defined as the ratio of the digital pulse volume during reactive hyperemia relative to the baseline. 93 patients (53 men) with an average age of 58±5 years completed the study, and 53 patients demonstrated coronary artery disease (CAD) after scheduled coronary angiography. There was a linear relationship between the hyperemia PAV index and FMD (r=0.69, p < 0.01). Similar to FMD, PAV was more impaired in patients with more cardiovascular risk factors (CRFs). The subjects with CAD had lower PAV index (1.05±0.23) and FMD (6.7%±2.9%) compared with those without CAD (PAT 1.41±0.37, FMD 10.4%±2.9%; P < 0.01 for both), and the relationship between FMD and PAV is also significant in both CAD (r=0.54, p < 0.01) and non-CAD (r=0.62, p < 0.01) patients. Endothelial function of digital artery assessed with the novel PAV method demonstrated a profile similar to that of brachial artery measured with FMD. The hyperemia PAV index was influenced by factors known to affect endothelial function, including CRFs and CAD, suggesting a role for PAV as a novel noninvasive test to study endothelial function.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Peripheral arterial volume distensibility changes with applied external pressure: significant difference between arteries with different compliance

This study aimed to quantify the different effect of external cuff pressure on arterial volume distensibility between peripheral arteries with different compliance. 30 healthy subjects were studied with the arm at two positions (0° and 45° from the horizontal level) to introduce different compliance of arteries. The electrocardiogram and finger and ear photoplethysmograms were recorded simultaneously under five external cuff pressures (0, 10, 20, 30 and 40 mmHg) on the whole arm to obtain arterial volume distensibility. With the applied external cuff pressures of 10, 20, 30 and 40 mmHg, the overall changes in arterial volume distensibility referred to those without external pressure were 0.010, 0.029, 0.054 and 0.108% per mmHg for the arm at the horizontal level, and 0.026, 0.071, 0.170 and 0.389% per mmHg for the arm at 45° from the horizontal level, confirming the non-linearity between arterial volume distensibility and external pressure. More interestingly, the significant differences in arterial volume distensibility changes were observed between the two arm positions, which were 0.016, 0.043, 0.116 and 0.281% per mmHg (all P < 0.01). Our findings demonstrated that arterial volume distensibility of peripheral arm arteries increased with external pressure, with a greater effect for more compliant arteries.

Decreased peripheral arterial volume distensibility in patients with branch retinal vein occlusion in comparison with normal subjects.

This study aimed to quantify arterial volume distensibility in patients with branch retinal vein occlusion (BRVO) in comparison with normal subjects and to investigate factors associated with their differences. 40 normal subjects and 30 BRVO patients were studied. Brachial-ankle pulse wave velocity (baPWV) was measured to determine arterial volume distensibility. In comparison with the normal subjects, after adjusting for pulse pressure, baPWV in the BRVO patients was significantly higher by 2.3 m/s (P < 0.01) and arterial distensibility was significantly lower by 0.015% per mmHg (P < 0.01). No subject in the normal group had an arterial distensibility lower than 0.04% per mmHg, in comparison with 67% (20/30) in the BRVO group. Arterial distensibility was significantly related to systolic and diastolic blood pressures (SBP and DBP) and ageing for both groups (all P < 0.05), but in the BRVO group, blood pressures and ageing had more prominent effect on arterial volume distensibility. Peripheral arterial distensibility has been shown to be significantly lower in BRVO patients in comparison with normal subjects. The more prominent effect of SBP, DBP and ageing on arterial distensibility indicates the potential underlying mechanisms of the interaction between higher blood pressures, ageing and BRVO disease.

Fourier analysis of peripheral blood pressure and flow in intraoperative assessment of infrainguinal arterial reconstructions.

To assess infrainguinal arterial reconstructions by intraoperative flowmetry under the distal anastomosis using a fast Fourier transformation; calculate and compare the amplitude ratios of peripheral arterial blood pressure and volume flow before and after drug-induced vasodilation of occluded bypass grafts and bypass grafts that have been patent at least for 1 year. To find what magnitude of the change of these ratios indicate a long-term patency of the bypass grafting. We compared the results of the intraoperative flowmetry tests of 97 patients with infrainguinal arterial reconstructions. The patients were divided into two groups based on the graft status: the grafts in 49 patients were patent for at least a year, and 48 patients had failed bypass. We used a fast Fourier transform (FFT) of the pressure and blood flow waves and compared the ratios of their amplitudes before and after administration of a vasodilator drug into the graft. Comparing the ratios obtained before and those after administration of the drug we quantified their change in each group and analysed them. After a drug-induced vasodilation, the blood pressure and flow amplitude ratios for the group with compromised reconstructions were less than 1.9 times smaller than those before drug infusion, while for the group with bypass grafts that had been functional for at least 12 months the ratios declined by more than 1.9 approximately 2 times. The magnitude of the change of amplitude ratios of the peripheral pressure and volume flow after drug-induced vasodilation can be used to make an assessment of the bypass graft and the distal arterial segment.

Noninvasive Vascular Function Measurement in the Community

Background— Several methods of noninvasive vascular function testing have been suggested for cardiovascular risk screening in the community. A direct comparison of the different methods and their relation to classical cardiovascular risk factors in a large cohort is missing. Methods and Results— In 5000 individuals (mean age, 55.5±10.9 years; age range, 35 to 74 years; women, 49.2%) of the population-based Gutenberg Heart Study, we performed simultaneous measurement of flow-mediated dilation (FMD) and peripheral arterial volume pulse determined by infrared photo (reflection index) and pneumatic plethysmography (PAT) and explored their associations. All function measures were recorded at baseline and after reactive hyperemia induced by 5-minute brachial artery occlusion. Correlations between different measures of vascular function were statistically significant but moderate. The strongest association for hyperemic response variables was observed for PAT ratio and FMD (Spearman r =0.17; age- and sex-adjusted partial correlation, 0.068). Classical risk factors explained between 15.8% (baseline reflection index) and 58.4% (brachial artery diameter) of the baseline values but only accounted for 3.2% (reflection index), 15.4% (FMD), and 13.9% (PAT ratio) of the variability of reflective hyperemic response. Regression models varied in their relations to classical risk factors for the individual vascular function measures. Consistently associated with different vascular function methods were age, sex, body mass index, and indicators of hypertension. Peripheral tonometry also showed a relation to fasting glucose concentrations. Conclusions— Noninvasive measures of conduit artery and peripheral arterial function are modestly correlated, differ in their relation to classical cardiovascular risk factors, and may thus reflect different pathologies.

Peripheral arterial volume distensibility: significant differences with age and blood pressure measured using an applied external pressure

A new arterial distensibility measurement technique was assessed in 100 healthy normotensive subjects. Arterial transmural pressures on the whole right arm were reduced with a 50 cm long cuff inflated to 10, 20, 30 and 40 mmHg. The electrocardiogram, and finger and ear photoplethysmograms were recorded simultaneously. Arm pulse propagation time, pulse wave velocity (PWV) and arterial volume distensibility were determined. With a 40 mmHg reduction in transmural pressure, arm pulse propagation time increased from 61 to 83 ms, PWV decreased from 12 to 8 m s−1 and arterial distensibility increased from 0.102% to 0.232% per mmHg (all P < 0.0001). At all cuff pressures, arterial distensibility was significantly related to resting mean arterial pressure (MAP), diastolic blood pressure (DBP) and age, and for systolic blood pressure at 30 and 40 mmHg (all P < 0.05). At 40 mmHg cuff pressure, arterial distensibility fell by 54% for a MAP increase from 75 to 105 mmHg, 57% for a DBP increase from 60 to 90 mmHg and 47% for an age increase from 20 to 70 years. These changes were more than double than those without cuff pressure. Our technique showed that systemic volume distensibility of the peripheral arm artery reduced with age, with a greater effect at higher external and lower transmural pressures.

Non-invasive quantification of peripheral arterial volume distensibility and its non-linear relationship with arterial pressure

Arterial wall function is associated with different physiological and clinical factors. Changes in arterial pressure cause major changes in the arterial wall. This study presents a simple non-invasive method to quantify arterial volume distensibility changes with different arterial pressures. The electrocardiogram, finger and ear photoplethysmogram were recorded from 15 subjects with the right arm at five different positions (90°, 45°, 0°, −45° and −90° referred to the horizontal level). Arm pulse propagation time was determined by subtracting ear pulse transit time from finger pulse transit time, and was used to obtain arterial volume distensibility. The mean arterial blood pressure with the arm at the horizontal level was acquired, and changes with position were calculated using the hydrostatic principle that blood pressure in the arm is linearly related to its vertical distance from the horizontal level. The mean arm pulse propagation times for the five different positions were 88, 72, 57, 54 and 52 ms, with the corresponding mean arterial volume distensibility of 0.234%, 0.158%, 0.099%, 0.088% and 0.083% per mmHg. For all consecutive changes in arm position, arm pulse propagation time and arterial volume distensibility, were significantly different (all probability P<0.05). The slopes of arm pulse propagation time and arterial volume distensibility against arterial pressure decreased significantly between each consecutive arm position from 90° to −45° (all P<0.01), indicating significant non-linearity. The experimental results fitted the physiological exponential model and Langewouters’ arctangent model well, and were also comparable to published data with arterial volume distensibility approximately tripling for transmural pressure changes from 101 to 58 mmHg. In conclusion, the inverse and non-linear relationship between arterial volume distensibility and arterial pressure has been quantified using a simple arm positioning procedure, with the greatest effect at low pressures. This work is an important step in developing a simple non-invasive technique for assessing peripheral arterial volume distensibility.

Catheter-Based Therapy for Atherosclerotic Renal Artery Stenosis

Atherosclerotic renal artery stenosis (RAS) is more common than has been previously appreciated1,2 and is an independent predictor of death regardless of the presence, severity, or method of revascularization of coronary artery disease.3–5 Among 1235 patients undergoing diagnostic coronary angiography, multivariate analysis demonstrated that RAS (>50%) was a stronger independent predictor of all-cause mortality (relative risk [RR], 2.9; 95% confidence interval [CI], 1.7 to 7.0) than congestive heart failure (RR, 2.3; 95% CI, 1.3 to 4.1), elevated left ventricular ejection fraction (RR, 1.7; 95% CI, 1.2 to 2.2), or decreased renal function (serum creatinine) (RR, 1.3; 95% CI, 1.1 to 1.5).3 A subsequent expansion of that study group, extended to 3987 patients undergoing abdominal aortography at the time of diagnostic cardiac catheterization, identified an incremental effect of the severity of RAS on the 4-year mortality rates. They found that a mild-to-moderate (50%) RAS was associated with a 30% 4-year mortality rate, which almost doubled (52%) with severe (>95%) RAS.4 The cause-and-effect relation between RAS and death is uncertain. It is possible that the presence of RAS is simply a marker for more diffuse or extensive atherosclerosis, which would result in more vascular-related deaths. However, there is one study5 that raises the possibility that the treatment of RAS with a renal stent in patients with renal insufficiency can improve mortality rates. In this trial, patients who improved their renal function after renal stent placement had significantly better survival rates compared with those whose renal function did not improve. A dedicated educational effort aimed at improving the diagnosis and treatment of peripheral arterial disease, including RAS, has been supported over the past 10 years by several professional societies.6–8 There is now objective evidence from the Medicare database that this effort to increase the number of patients …

脳動脈瘤クリップ時における末梢側動脈の継続的血流速モニターの有用性

脳動脈瘤クリップ時における末梢側動脈の継続的血流速モニターの有用性

The sequence of cellular and hemodynamic changes of chronic pulmonary hypertension induced by hypoxia and other stimuli.

It has been suggested that the lung has only a narrow range of structural responses to injury. For example, long-term injury results in emphysema, fibrosis, and pulmonary hypertension. Clinical and experimental models of chronic pulmonary hypertension suggest that this disease can be triggered by a number of interventions and that the structural changes in the pulmonary arterial circulation may vary depending on the stimulus. This report briefly reviews the structural changes that accompany the development of pulmonary hypertension in hypoxia- and Crotalaria-induced pulmonary hypertension in the rat and in repeated endotoxemia and continuous air embolization in the sheep. The studies indicate that of the structural changes considered characteristic of chronic pulmonary hypertension, the reduction in peripheral arterial volume as reflected by a loss in number of barium-filled arteries, extension of muscle into smaller intra-acinar arteries than normal, and reduction in external diameter of intra-acinar arteries are the changes that contribute to the sustained rise in pulmonary artery pressure. Increased medial and adventitial thickness of the normally muscular arteries seem to be secondary changes to this disease. Because the severity and range of structural changes differ between the experimental models of pulmonary hypertension, the data suggest that the lung, particularly the pulmonary arterial circulation, may have a more complex response to injury than originally suspected.