Restoring lower limb blood flow improves conduction velocity in diabetic patients

Summary Human diabetic peripheral neuropathy is believed to have, at least in part, a microvascular basis. This study was designed to examine the effects of restoration of arterial blood supply on peripheral nerve function in six non-insulin-dependent diabetic patients with peripheral occlusive vascular disease. In the revascularised legs, transcutaneous oxygen increased from a median 37.5 (28.5–45.7 interquartile range) mmHg to 55.5 (53.5–62.5) mmHg, p=0.036, mean increase 20.2 (14.8–25.6, 95% confidence intervals(CI)) mmHg. This was accompanied by a significant improvement in peroneal motor nerve conduction velocity from 31.7 (26.5–36.3) m/s to 33.5 (32.9–39.4) m/s, p=0.04, mean increase 4.7 (1.7–7.7, 95% CI) m/s. There was no significant change in transcutaneous oxygen or peroneal nerve motor conduction velocity in the contralateral control limbs. This improvement in conduction velocity with improved tissue oxygenation suggests that studies of agents which might indirectly bring about improvements in microvascular blood flow should be urgently considered.Abbreviations NIDDM Non-insulin-dependent diabetes mellitus - MCV motor conduction velocity - TcPO₂ transcutaneous oxygen     

Doppler echocardiography and lower limb arteriopathy obliterans

Duplex Doppler ultrasonography became the first line investigation in patients with lower limb arterial disease. It use the ultrasonic technology coupled to computer. Constant progress of duplex Doppler ultrasonography, as color flow imaging or power Doppler and more simply continuous refinements in grey scale image resolution, associated with the expansion of the interventional endovascular processing explains its significant development these last years. This simple non invasive technique is now an essential complement of physical examination. It is thus an usual tool use in common practice by vascular physicians and surgeons from tracking till processing while passing by the diagnosis. Duplex Doppler ultrasonography gives accurate informations about both structural and dynamic anomalies in the peripheral lower limb. It thus allows the evaluation, the quantification and the follow-up of the arterial diseases by carrying out a precise vascular mapping that can guides the radiological or surgical processing if necessary. Duplex Doppler ultrasonography remains however "operator depending" and moreover cannot replace the appropriate clinical decision making and medical therapeutic strategy.     

Endothelial control of lower limb blood flow in chronic heart failure.

BACKGROUND: Limitation of the blood supply to skeletal muscle in chronic heart failure may contribute to the symptoms of fatigue and diminished exercise capacity. The pathophysiology underlying this abnormality is not known. The purpose of this study was to assess the effect of endothelium dependent and independent vasodilator agents on blood flow in the leg of patients with heart failure. METHODS AND RESULTS: Blood flow in the leg was measured in patients with heart failure (n = 20) and compared with that in patients with ischaemic heart disease and normal left ventricular function (n = 16) and patients with chest pain and normal coronary arteries (n = 8). External iliac artery blood flow was measured using intravascular Doppler ultrasound and quantitative angiography. Flow was recorded at rest and in response to bolus doses of the endothelium independent vasodilator, papaverine. Endothelium dependent responses were measured by infusion of acetylcholine and substance P. Mean (SEM) baseline blood flow was reduced at rest (2.9 (0.4) v 4.5 (0.3) ml/s, P < 0.001) and vascular resistance was raised (37.4 (3.6) v 27.1 (3.0) units, P < 0.05) in patients with heart failure compared with that in controls. The peak blood flow response to papaverine (8 mg), acetylcholine (10(-7)-10(-5) mol/l), and substance P (5 pmol/min) was reduced in heart failure, with greater impairment of the response to acetylcholine than substance P. There was a correlation between baseline blood flow in the heart failure group and diuretic dose (r = -0.62, P = 0.003), New York Heart Association classification (r = -0.65, P = 0.002), and left ventricular ejection fraction (r = 0.80, P = 0.0004). CONCLUSIONS: There is reduced blood flow and raised vascular resistance at rest in the legs of patients with heart failure. The degree of impaired blood flow in the leg correlates with the severity of heart failure. There is impairment of the response to both endothelium dependent and independent vasodilators. Abnormal function of the vascular myocyte in heart failure may explain these results as would structural abnormalities of the resistance vessels.     

外伤致下肢深静脉血栓的二维及彩色多谱勒超声诊断

目的探讨二维及彩色多谱勒超声(2D-CDFI)在下肢深静脉血栓(DVT)诊断中的应用.方法对30例 52条DVT进行2D-CDFI检查,平卧位检查股静脉、俯卧位检查腘静脉及小隐静脉.记录分析每一静脉节段纵切和横切观察资料.结果DVT超声可表现为腔内强弱不等回声和充盈缺损;CDFI示无血流信号或血流频谱变直.超声诊断符合率为60%(18/30).结论2D-CDFI是临床诊断双下肢深静脉血栓(DVT)的一个有效方式.     

Doppler ultrasonographic evaluation of splanchnic blood flow in coeliac disease.

BACKGROUND: Current knowledge on splanchnic haemodynamics in coeliac disease is limited and incomplete. AIM: To evaluate splanchnic arterial and venous blood flow in coeliac disease. METHODS: In 22 coeliac (13 untreated, nine treated) patients and in nine healthy subjects the following variables were assessed: vessel diameter and mean flow velocity in portal vein, splenic vein, superior mesenteric vein, and superior mesenteric artery. Peak systolic velocity, end diastolic velocity and pulsatility index were also determined in the superior mesenteric artery. Five patients of the untreated group were re-evaluated after nine months on a gluten free diet. RESULTS: Significant differences in haemodynamic variables between the three groups were shown only in the superior mesenteric artery. An increase in both mean flow velocity and end diastolic velocity and a reduction in pulsatility index occurred in untreated patients compared with treated patients (p < 0.002; p < 0.04; p < 0.035) and with healthy controls (p < 0.001; p < 0.025; p < 0.0003). Similar results were obtained for the five patients evaluated before and after treatment (p < 0.03; p < 0.02; p < 0.03), in whom the mean flow velocity in the superior mesenteric vein also decreased after treatment (p < 0.05). No significant differences were noted between treated coeliac patients and healthy controls. CONCLUSIONS: In untreated coeliac disease there is a hyperdynamic mesenteric circulation that decreases after treatment.     

Doppler flow velocity determination in the lower extremities

The clinical application of Doppler velocity measurement is reviewed as a diagnostic tool in arterial disease of the lower extremity. Emphasis is placed on the importance of quantitative evaluation of the recorded tracings. Various aspects of qualitative, semi-quantitative and quantitative evaluation are discussed. Included are also some more special applications as pedal arch examination, profunda femoris and penile arteries velocity evaluation.     

应用彩色多普勒超声检测脑血流灌注评价血管性痴呆

目的:探讨采用彩色多普勒超声检测颈内动脉及椎动脉血流估测脑血流灌注在评价血管性痴呆(VD)中的价值。方法:VD患者56例,对照组42例,采用GE Vivid 7彩色多普勒超声诊断仪,检测颈内动脉和椎动脉颅外段的血管内径、收缩期最大峰值流速(Vm)及流速-时间积分(VTI)以计算颈内动脉及椎动脉的每分血流量,2者相加获得总的血流量。结果:VD组双侧颈内动脉和椎动脉的Vm、颈内动脉血流量和总血流量均较对照组下降(P<0.05)。MMSE评分与总血流量呈正相关。结论:通过彩色多普勒超声对颈内动脉、椎动脉血流量指标进行检测,可较准确反映血管性痴呆患者脑血流灌注的改变,是一种研究血管性痴呆的有效方法和手段。     

Comparison of multiple views for the evaluation of pulmonary arterial blood flow by Doppler echocardiography

Forty adult patients underwent Doppler and two-dimensional echocardiographic examination of the pulmonary artery from multiple views to determine the variability in the magnitude of Doppler-determined flow velocity and pulmonary arterial diameter from various echocardiographic windows. Flows were recorded from two or more views in 32 patients (80%). Twelve of these patients (38%) had flow velocities recorded from two or more views that were within 6% of each other. Twenty of these patients (62%) had view-dependent differences in measured flow velocity ranging from 7% to 48%. The commonly used parasternal short-axis view yielded the highest pulmonary arterial flow velocity in only 35% of the patients studied. Determinations of pulmonary arterial blood flow can vary markedly when measured from different sites, and this is presumably due to varying ability to approximate a zero-degree Doppler angle from different views. Measurement of pulmonary arterial flow velocity should be attempted from multiple views, and the highest flow velocity should be selected as that obtained with the best zero-degree Doppler angle approximation.     

Extracranial carotid Doppler ultrasound evaluation of cerebral blood flow volume in COPD patients

OBJECTIVE: Doppler ultrasound of extracranial internal carotid artery (ICA) and vertebral artery (VA) were performed and total cerebral blood flow volume (tCBFV) was evaluated in chronic obstructive pulmonary disease (COPD) patients. CBFV changes due to blood gas changes were also evaluated. METHODS: Bilateral ICA and VA have been examined with 7.5 MHz linear array transducer in COPD patients. Angle-corrected time averaged flow velocity and cross-sectional areas of vessels have been measured. Flow volumes and tCBFV have been calculated. Flow velocities and waveform parameters have been measured. RESULTS: tCBFV, anterior-posterior CBFVs, left-right ICA flow volumes, bilateral ICA and VA cross-sectional areas and left ICA peak-systolic velocity were significantly higher in COPD patients than control group. Among COPD patients tCBFVs were highest in hypoxemic-hypercapnic ones, and lowest in normocapnic ones. Bilateral VA flow volumes, bilateral ICA (except left ICA V(ps)) and VA flow velocities and waveform parameters were not different in COPD patients compared with control group. When compared among the subgroups of COPD patients, there were no significant differences for all parameters. CONCLUSION: tCBFVs were found to be significantly higher in COPD patients. This increment which is probably due to balancing the oxygen deficit is low with hypoxemia and high with hypercapnia and hypoxemia. Particularly, bilateral ICA and VA cross-sectional area changes and increased left ICA V(ps) were considered as the main reason for increased tCBFV in COPD patients.     

Blood flow analysis of the head and lower limbs by the laser Doppler blood flowmeter during LDL apheresis

The presence of peripheral arterial disease substantially increases the risk for both morbidity and mortality among end-stage renal disease patients. Low-density lipoprotein (LDL) apheresis has been also applied for the treatment of peripheral arterial disease to reduce LDL levels, resulting in the improvement of the blood flow to the ischemic limbs. In this study, we investigated the continuous changes of the tissue blood flows in the lower limbs and head during LDL-apheresis treatment by a non-invasive method (the non-invasive continuous monitoring method (NICOMM) system). In this study, the tissue blood flow in both the head and lower limbs showed a significantly enhancement from before to after treatment. The tissue blood flow in the lower limbs showed a significantly larger improvement than that in the head. The short-term effects of LDL apheresis were confirmed by using the NICOMM system; thus, this system will be useful for the determination of the appropriate schedule of LDL apheresis for long-term effectiveness.     

Value of transesophageal color Doppler echocardiography in the evaluation of coronary artery anatomy and blood flow

The purpose of this study was to test the efficacy of newly developed biplane transesophageal color Doppler and two-dimensional echocardiography in the evaluation of coronary artery anatomy and blood flow. Using these two techniques, high quality images of the entire main left coronary artery (from the left coronary ostium to the bifurcation of the left anterior descending and circumflex coronary arteries), adequate for assessment of luminal diameter and percent stenosis, were obtained in 34 (89%) out of 38 patients. Transesophageal color Doppler echocardiography visualized coronary blood flow in 32 (84%) of the 38 patients. Transesophageal two-dimensional echocardiography clearly showed significant (50% of greater) narrowing of the coronary lumen in 10 out of 12 patients (sensitivity; 83%) and insignificant narrowing or no abnormalities of the coronary lumen in 23 of 26 normal individuals (specificity; 88%). This preliminary study suggests that biplane transesophageal color Doppler and two-dimensional echocardiography are feasible, noninvasive techniques for imaging the main left coronary artery and blood flow.     

Intravascular Doppler for the evaluation of renal blood flow: validation and demonstration of vessel reactivity

AIM: To assess the feasibility and to demonstrate the potential clinical application of intravascular doppler in the evaluation of renal blood flow in patients with hypertension and normal renal arteries.MATERIALS AND METHODS: Intravascular doppler was used to measure renal blood flow in 19 patients (34 kidneys) during arteriography to rule out renovascular hypertension. Arteriography showed no evidence of renal artery stenosis in any patient. Hemodynamic parameters, renal artery diameter, and doppler measurements were undertaken at baseline, after injection of a bolus (10 ml) of normal (0.9%) saline, and after injection of isosorbide dinitrate (1 mg diluted in 10 ml normal saline).RESULTS: Repeated measurements of renal blood flow confirmed the reproducibility of the technique. Basal blood flow was similar in both right and left kidneys; injection of vehicle solution (10 ml normal saline) had no effect on doppler parameters. Injection of isosorbide dinitrate resulted in a significant increase in renal blood flow velocity reflecting an increase in renal blood flow; this demonstrates the existence of a renal flow reserve. The degree of increase in renal blood flow varied significantly between kidneys.CONCLUSIONS: Intravascular doppler is a safe, effective, and reproducible technique for measurement of renal blood flow. It allows evaluation of variations in renal blood flow in response to diverse vasoactive drugs or other vasomotor stimuli. The present study demonstrated the heterogenous response of renal blood flow in response to vasodilator stimuli.     

Role of transmitral blood flow velocity by Doppler echocardiography in the evaluation of coronary artery disease

To determine the relation between presence and severity of coronary artery disease and diastolic filling abnormalities by Doppler echocardiography, recordings of transmitral inflow velocity were made at rest in 90 patients with coronary artery disease and 28 normals. At the time of the Doppler examination, 81 patients with coronary artery disease (90%) and 10 normals (36%) were treated with antianginal medications. No difference was found in the ratio between early (E) and late (A) diastolic filling velocity (E/A ratio) when comparing patients with greater than 70% obstruction of at least one coronary artery to age-matched normals, regardless of the presence or absence of wall motion abnormalities. The E/A ratio was 1.3 +/- 0.46 in coronary patients with normal wall motion, 1.2 +/- 0.47 in coronary patients with abnormal wall motion, and 1.3 +/- 0.53 in both samples of age-matched normals. Multivariate analysis of the relation between E/A ratio and other variables showed that heart rate (F = 24.46, p less than 0.00001) and age (F = 19.51, p less than 0.00001) were significant independent determinants of the E/A ratio, while the presence or severity of coronary artery disease, the presence of hypertension, the magnitude of wall motion abnormalities, and end-diastolic dimension by echocardiography were not. These data suggest that transmitral inflow velocity recordings by Doppler have limited value for the recognition of coronary artery disease, since the E/A ratio is profoundly influenced by other factors, such as heart rate and age.     

Color flow Doppler in the evaluation of aortic aneurysms

Fifteen patients with aortic aneurysms have been evaluated with Doppler color flow imaging. Two distinct flow patterns are noted: a smooth laminar pattern and a turbulent circuitous pattern. It is postulated that those patients with a turbulent pattern may be at greater risk for aneurysm enlargement and rupture.     

Doppler echocardiographic evaluation of pulmonary blood flow after the Fontan operation: the role of the lungs.

OBJECTIVE--To document whether the act of respiration influences pulmonary blood flow in patients after the Fontan operation. DESIGN--Prospective study in which patients acted as their own controls. SETTING--Supraregional paediatric cardiology centre. PATIENTS--Sixteen patients who had undergone atriopulmonary anastomosis (Fontan operation) for the treatment of congenital heart disease. INTERVENTION--Doppler assessment of pulmonary artery flow patterns with a simultaneous respirometer, electrocardiogram and phonocardiogram. RESULTS--Total (mean (1SD) ) forward pulmonary flow was 63.6 (35)% higher during inspiratory cardiac cycles than during expiratory ones. CONCLUSIONS--The act of breathing provides an additional energy supply to pulmonary blood flow in patients after the Fontan operation.     

Doppler echocardiographic evaluation of pulmonary blood flow after the Fontan operation: the role of the lungs.

OBJECTIVE--To document whether the act of respiration influences pulmonary blood flow in patients after the Fontan operation. DESIGN--Prospective study in which patients acted as their own controls. SETTING--Supraregional paediatric cardiology centre. PATIENTS--Sixteen patients who had undergone atriopulmonary anastomosis (Fontan operation) for the treatment of congenital heart disease. INTERVENTION--Doppler assessment of pulmonary artery flow patterns with a simultaneous respirometer, electrocardiogram and phonocardiogram. RESULTS--Total (mean (1SD) ) forward pulmonary flow was 63.6 (35)% higher during inspiratory cardiac cycles than during expiratory ones. CONCLUSIONS--The act of breathing provides an additional energy supply to pulmonary blood flow in patients after the Fontan operation.     

联合检测踝臂指数与彩超检测下肢血管对于诊断老年下肢血管疾病的价值

目的：探讨联合检查踝臂指数（ABI）与彩超检测外周血管对于诊断下肢血管疾病的价值。方法：156例老年患者在我院测定了ABI并在超声科以彩超做了下肢血管检查,现就下肢血管彩超检查结果和ABI值进行对照分析。结果：156例下肢血管彩超有异常改变的患者中,ABI〈0.5者7例（4.5%）,0.89～0.5者97例（62.2%）,1.08～0.90者35例（22.4%）,1.30～1.09者17例（10.9%）,即ABI〈0.90时血管病变的比例明显高于ABI≥0.9组（P〈0.01）。当ABI指数在0.89～0.50这个区间,下肢血管的病变率（62.2%）最高。当下肢血管有斑块形成后,ABI指数0.89～0.50的比例高达69.2%。结论：联合检查踝臂指数与以彩超检查下肢血管对下肢血管疾病诊断具有重要意义。     

Doppler ultrasound evaluation of acute effects of cigarette smoking on portal blood flow in man

The acute systemic haemodynamic effects of cigarette smoking are well known, but there are no studies dealing with the possible smoke-related acute changes of splanchnic circulation in man. In the present study we evaluated the acute effects of cigarette smoking on portal blood flow (PBF) in normal subjects by the use of Doppler ultrasound. Twenty-three normal volunteers were asked to smoke two cigarettes with a known total nicotine content (1.1 mg each) in a supine position. Each cigarette was smoked during a 5 min period and a 5 min interval between the two cigarettes was allowed. Both mean PBF velocity and volume were evaluated at time 0 (basal values) and 8, 15, 30, 45 and 60 min after the first inhalation of the first cigarette. The basal mean PBF velocity (22 cm/s; 95% CI 20.9–24.2) was significantly decreased at 8 min (19 cm/s; 95% CI 17.9–20.8; P< 0.0007) and 15 min (20 cm/s; 95% CI 17.8–21.3; P< 0.005). Similarly, the PBF volumes at 8 min (710 mL/min; 95% CI 660–876; P< 0.002) and 15 min (750 mL/min; 95% CI 650–862; P< 0.005) were significantly lower than those measured at time 0 (850 mL/min; 95% CI 766–987). Both mean PBF velocity and volume measured at successive times did not differ significantly from basal values. The present study shows that cigarette smoking causes acute and transient reduction of PBF velocity and volume in normal subjects.