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A N Nicolaides

Publications and source records attributed to A N Nicolaides.

At least 19 recordsLinked to original sources
PubMed2006

Texture analysis of ultrasonic images of symptomatic carotid plaques can identify those plaques associated with ipsilateral embolic brain infarction.

OBJECTIVES: The aim of our study was to determine the association between objective, computerised texture analysis of carotid plaque ultrasonic images and embolic CT-brain infarction in patients presenting with hemispheric neurological symptoms. DESIGN: Cross-sectional study in patients with 50%-99% (ECST) carotid stenosis. PATIENTS AND METHODS: Carotid plaque ultrasonic images (n=54, 26 with TIAs and 28 with stroke) obtained during carotid ultrasound were normalised and standardised for resolution and subsequently assessed visually for the presence of discrete echogenic or juxtaluminal echolucent components and overall echogenicity (plaque type). Using computer software, 51 histogram/textural features of the plaque outlines were calculated. Factor analysis was subsequently applied to eliminate redundant variables. Small cortical, large cortical and discrete subcortical infarcts on CT-brain scan were considered as being embolic. RESULTS: Twenty-five cases (46%) had embolic infarcts. On logistic regression, grey-scale median (GSM), a measure of echolucency, spatial grey level dependence matrices (SGLDM) correlation and SGLDM information measure of correlation-1, measures of homogeneity were significant (p<0.05), but not grey level runlength statistics (RUNL) Run Percentage (RP), stenosis severity, type of symptoms or echolucent juxtaluminal components. Using ROC curves methodology, SGLDM information measure of correlation-1 improved the value of GSM in distinguishing embolic from non-embolic CT-brain infarction. CONCLUSION: Computerised texture analysis of ultrasonic images of symptomatic carotid plaques can identify those that are associated with brain infarction, improving the results achieved by GSM alone. This methodology could be applied to prospective natural history studies of symptomatic patients not operated on or randomised trials of patients undergoing carotid angioplasty and stenting in order to identify high-risk subgroups for cerebral infarction.

Algorithms↗
PubMed2006

Haemodynamic and clinical impact of superficial, deep and perforator vein incompetence.

OBJECTIVE: The purpose of this study was to assess the effect of venous incompetence of the deep, superficial and perforator veins combined (i.e. multi-system incompetence) on the venous haemodynamics and clinical condition of limbs with chronic venous disease (CVD). METHODS: One hundred and thirty two limbs (16-C(1); 30-C(2); 20-C(3); 25-C(4); 21-C(5); 20-C(6)) of 121 patients were studied. We excluded those with previous venous surgery/sclerotherapy, peripheral arterial disease, recent deep vein thrombosis (< or =6 months), or inability to comply with the tests. The CEAP clinical class was assessed. Duplex ultrasonography (ultrasound) enabled classification according to: the presence of superficial([S]) (+/- perforator([P])) or deep([D]) (+/-S, +/-P) reflux (>.5s); the number of incompetent venous systems (single-system([S/P/D]), dual-system([S+P/S+D/P+D]), or triple-system([S+P+D])), and the number of incompetent perforators([0/1/2/> or =3]). The amount of reflux (Venous Filling Index([VFI])); calf pump Ejection Fraction([EF]), and Residual Volume Fraction([RVF]) were studied with air-plethysmography. RESULTS: VFI in limbs with triple-system incompetence (VFI median 6.68 [IQR: 4.7-9.7]ml/s) was higher than in limbs with dual-system incompetence (4.5 [2.1-7.4]ml/s), and VFI in the latter was higher than in limbs with single-system incompetence (1.3 [0.69-2.3]ml/s)(p<0.01 Kruskal-Wallis). Although EF changes were small, RVF in limbs with triple-incompetence (39 [30-51] %) was higher than in single-system incompetence (26 [16-33] %)(p<0.01 Mann-Whitney). Limbs with superficial (+/-P) incompetence had a lower VFI (p<0.01) and RVF (p<0.02) than limbs with deep (+/-S+/-P) incompetence, and limbs with > or =2 incompetent perforator veins had a higher VFI (p<0.04) than those without perforators. All limbs with single-system incompetence were C(1-3,) whereas 78% of those with triple-incompetence were C(4-6) (p<0.01). The number of incompetent systems increased with clinical class (p<0.01). CONCLUSIONS: The frequency of incompetence of more than one venous system increased with the clinical severity of venous disease and was accompanied by a 5-fold increase in the amount of reflux and a 50% rise in the RVF. The number of incompetent perforators per limb increased with the amount of reflux. The number of incompetent venous systems (superficial, deep, perforator) and perforator veins can be assessed by duplex ultrasound giving an objective indication of the functional severity of venous disease. In this way duplex ultrasound could be used to grade venous function in clinical practice as an alternative to APG measures which are less widely available.

Adult↗
PubMed2005

Improvement of the walking ability in intermittent claudication due to superficial femoral artery occlusion with supervised exercise and pneumatic foot and calf compression: a randomised controlled trial.

OBJECTIVES: To compare the effect of unsupervised exercise, supervised exercise and intermittent pneumatic foot and calf compression (IPC) on the claudication distance, lower limb arterial haemodynamics and quality of life of patients with intermittent claudication. METHODS: Thirty-four eligible patients with stable intermittent claudication were randomised to IPC (n = 13, 3h/d for 6 months), supervised exercise (n = 12, three hourly sessions/week for 6 months) or unsupervised exercise (n = 9). In each patient, initial claudication distance (ICD), absolute claudication distance (ACD), resting ankle brachial pressure index (ABPI), and resting hyperaemic calf arterial inflow were measured before, 6 weeks, 6 months and 1 year after randomisation. Quality of life was assessed with the short form (SF)-36, walking impairment (WIQ) and intermittent claudication questionnaires (ICQ). RESULTS: Compared with unsupervised exercise, both IPC and supervised exercise, increased ICD and ACD, up to 2.83 times. IPC increased arterial inflow (p < 0.05 at 6 weeks) and ABPI. Supervised exercise decreased arterial inflow and increased ABPI (p < 0.05 at 6 months). Unsupervised exercise had no effect on arterial inflow or ABPI. IPC improved significantly the ICQ score and the speed score of the WIQ, while supervised exercise improved the WIQ claudication severity score. At 1 year clinical effectiveness of supervised exercise and IPC was largely preserved. CONCLUSIONS: IPC, by augmenting leg perfusion, achieved improvement in walking distance comparable with supervised exercise. Long-term results in a larger number of patients will provide valuable information on the optimal treatment modality of intermittent claudication.

Aged↗
PubMed2005

Severity of asymptomatic carotid stenosis and risk of ipsilateral hemispheric ischaemic events: results from the ACSRS study.

OBJECTIVES: This study determines the risk of ipsilateral ischaemic neurological events in relation to the degree of asymptomatic carotid stenosis and other risk factors. METHODS: Patients (n=1115) with asymptomatic internal carotid artery (ICA) stenosis greater than 50% in relation to the bulb diameter were followed up for a period of 6-84 (mean 37.1) months. Stenosis was graded using duplex, and clinical and biochemical risk factors were recorded. RESULTS: The relationship between ICA stenosis and event rate is linear when stenosis is expressed by the ECST method, but S-shaped if expressed by the NASCET method. In addition to the ECST grade of stenosis (RR 1.6; 95% CI 1.21-2.15), history of contralateral TIAs (RR 3.0; 95% CI 1.90-4.73) and creatinine in excess of 85 micromol/L (RR 2.1; 95% CI 1.23-3.65) were independent risk predictors. The combination of these three risk factors can identify a high-risk group (7.3% annual event rate and 4.3% annual stroke rate) and a low risk group (2.3% annual event rate and 0.7% annual stroke rate). CONCLUSIONS: Linearity between ECST per cent stenosis and risk makes this method for grading stenosis more amenable to risk prediction without any transformation not only in clinical practice but also when multivariable analysis is to be used. Identification of additional risk factors provides a new approach to risk stratification and should help refine the indications for carotid endarterectomy.

Brain Ischemia↗
PubMed2005

Thrombophilia and venous thromboembolism. International consensus statement. Guidelines according to scientific evidence.

Thrombophilia is the term now used to describe predisposition to increased risk of venous and occasionally arterial thromboembolism due to hematological abnormalities. It can be a multifactorial disorder where congenital defects of anticoagulant or procoagulant factors may be combined with acquired hematological abnormalities. It should be considered in patients with a documented unexplained thrombotic episode or a positive family history. The aim of this document is to provide guidelines for investigation and management of patients with thrombophilia in the presence or absence of venous thromboembolism (VTE).

Activated Protein C Resistance↗
PubMed2005

Comparison of two intermittent pneumatic compression systems. A hemodynamic study.

AIM: Sequential leg compression has been previously shown to be superior to uniform compression. The aim of our study was to compare the hemodynamic effectiveness of the portable sequential compression device (SCD Express Compression System, Tyco Healthcare Group LP, Mansfield, MA, USA) with a rapid inflation device (VenaFlow, Aircast, Inc, Summit, NJ, USA). The former, by sensing venous refill time, commences compression when the calf veins are refilled. METHODS: The two devices were tested in 12 normal volunteers in the semirecumbent position using duplex ultrasound. Baseline and augmented flow velocity and volume flow were measured at the level of the common femoral vein, above the saphenofemoral junction. Refilling time was determined from velocity recordings of the common femoral vein. Total and peak volume of blood expelled per hour during compression were calculated using flow data and the individual cycling rate. RESULTS: Both devices increased venous flow velocity, up to 3.8 times the baseline (all P<0.001). Refill time of the rapid inflation device was shorter in comparison with the sequential compression device (15+/-2.2 vs 25+/-4 s; P<0.001), suggesting incomplete vein evacuation. The sequential compression device, by augmenting flow throughout a significantly longer compression period per cycle (10.9 s vs 6.3 s), expelled significantly more venous blood (121+/-68 vs 81+/-63 mL; P<0.001). Similarly, the total volume of blood expelled per hour with the sequential compression device was 100% higher than the rapid inflation device (9685+/-5426 vs 4853+/-3658 mL; P<0.001). Although peak velocity enhancement was higher with the rapid inflation device, flow augmentation (a product of average blood flow velocity) was comparable (669+/-367 vs 771+/-574 cm/s; P=0.223) with the sequential compression device, mainly because the rapid inflation device failed to maintain flow enhancement beyond the initial flow surge. CONCLUSIONS: Sequential compression showed hemodynamic superiority compared to a rapid inflation device. This was enhanced further by the sensing of refill time, which resulted in more compression cycles over time. The relative efficacy of the two devices in deep vein thrombosis prevention should be tested in future studies.

Blood Flow Velocity↗
PubMed2003

Prevention of venous thrombosis with elastic stockings during long-haul flights: the LONFLIT 5 JAP study.

The aim of this study was to evaluate deep venous thrombosis (DVT) prophylaxis with specific elastic stockings in long-haul flights (11-13 hours), in high-risk subjects. A group of 300 subjects was included; 76 were excluded for several problems including concomitant treatments; 224 were randomized into two groups (stockings vs. controls) to evaluate prophylaxis with below-knee stockings. An exercise program was used in both groups. Scholl (UK) Flight Socks (14-17 mmHg of pressure at the ankle) were used. DVT was diagnosed with ultrasound scanning. The femoral, popliteal, and tibia] veins were scanned before and within 90 minutes after the flights. Of the 205 included subjects, 102 controls and 103 treated subjects completed the study. Drop-outs were due to flight connection problems. Age, gender, and risk distributions were comparable in the two groups. In the treatment group (103 subjects; mean age, 42; SD 9; M:F, 55:48), one limited, distal DVT was observed (0.97%). In the control group (102 subjects; mean age, 42.1; SD 10.3; M:F, 56:46), six subjects (5.8%) had a DVT. There were no superficial thromboses. The difference in DVT incidence is significant (p<0.0025; six times greater in the control group). Intention-to-treat analysis counts 18 failures in the control group (12 lost to follow-up + six thromboses) of 112 subjects (15.8%) versus eight failures (7.3%) in the treatment group (p<0.05). The tolerability of the stockings was very good and there were no complaints or side effects. All events were asymptomatic. Considering these observations, Scholl Flight Socks are effective in reducing the incidence of DVT in high-risk subjects.

Adult↗
PubMed2003

[Treatment of a femoral venous aneurysm with foam-sclerotherapy].

Venous aneurysms are uncommon. Venous dilatation and large varices could be treated with injections of foam and sclerosing agents followed by local compression which obliterate or thrombose the aneurysmal space. However, the use of foam-sclerotherapy to obliterate venous aneurysms has never been reported before. The obstruction or sclerosis of the aneurysmal space should be obtained without altering the femoral flow. The patient is a 65-year old lady without history of trauma involving the femoral region. A compressible lump is present at the third, internal part of the left femoral fold. The lump is painless and easily obliterated by compression. Color duplex shows a large cavity (4 x 4 x 6 cm) and venous flow is visible. Flow produces a venous jet, visible with color and ejecting from the common femoral vein. A first injection is made under ultrasound guide using a foaming agent: 10 ml of foam including 4 ml of 3% sclerosing solution are injected. During the injection the femoral vein is compressed with the probe to avoid passage of the sclerosing foam into the femoral vein. After 2 weeks, ultrasound indicate only a partial occlusion of the aneurysm. The procedure is repeated and after 2 more weeks the ultrasound scan shows a complete occlusion of the aneurysm. The femoral vein and the long saphenous vein are patent. After 12 weeks the situation is unchanged and the results appear to be permanent. This new method, never described before is an important, minimally invasive method in case of venous aneurysms. Results from larger studies should be available to define indications and modalities of treatment.

Aged↗
PubMed2002

Platelet activation during carotid endarterectomy and the antiplatelet effect of Dextran 40.

OBJECTIVE: To determine changes in platelet activation during carotid endarterectomy (CEA) and the antiplatelet effect of Dextran 40. METHODS: Prospective study in 40 patients undergoing CEA. Platelet activity was measured by whole blood flow cytometry and platelet aggregometry during CEA. The expression of P-selectin and the PAC-1 antigen were used as markers of platelet activation and aggregation. Patients received aspirin (75-300 mg) preoperatively and 5,000 units unfractionated heparin during surgery. High intensity transient signals (HITS) in the ipsilateral middle cerebral artery were monitored using transcranial Doppler (TCD) perioperatively. RESULTS: P-selectin expression increased after carotid clamping (P < 0.01) and clamp release (P < 0.05). There was higher expression of PAC-1 after carotid clamping (p < 0.05). Spontaneous and ADP-induced platelet aggregation increased after carotid clamping (P< 0.01) and release (P < 0.01). TCD monitoring showed an increased HITS count from preoperative levels, after clamp release (P < 0.01) and during recovery (P < 0.01). After the operation, patients with more than 50 HITS per 30 min were started on an infusion of dextran 40 (n = 6). P-selectin expression decreased 24 h after dextran 40 (P < 0.01). CONCLUSION: Significant platelet activation and aggregation occurs during CEA despite the current use of antiplatelet treatment. Dextran 40 had an antiplatelet effect after CEA providing further evidence that it may contribute to reducing thromboembolic complications.

Aged↗
PubMed2002

[Treatment of severe intermittent claudication: ORACLE-PGE1 short term study. A randomised 40-week study. Evaluation of efficacy and costs].

BACKGROUND: The efficacy and cost of prostaglandin E1 (PGE1) in severe intermittent claudication was studied comparing a long-term protocol (LTP) with a short-term protocol (STP) in a randomised 40-week study. METHODS: Phase 1 was a 2-week run-in phase (no treatment) for both protocols. In LTP, phase 2 was the main treatment phase. Treatment was performed with 2-hour infusions (60 micro g PGE1, 5 days each week for 4 weeks. In phase 3 (4-week interval period), PGE1 was administered twice a week (same dosage). In phase 4 (40 weeks), no PGE1 were used. In STP, phase 2 treatment was performed in two days by a 2-hour infusion (60 micro g PGE1 twice a day in 2 days). The same cycle was repeated every 4 weeks. A treadmill test was performed at inclusion, at the beginning of each phase and at the end of weeks 12, 16, 20 32 and 40. A progressive training plan (walking) and reduction in risk factors plan was used in both groups. RESULTS: Out of the 1276 included patients 1165 completed the study (606 in LTP group; 559 in the STP). Drop-outs were 111. The two groups were comparable in distribution, risk factors and smoking. Intention-to-treat analysis indicated an increase in pain free walking distance (PFWD). The absolute and percent increase in pain-free walking distance (PFWD) was comparable in both LTP and STP groups with a significative increase in TWD at 4 weeks. At 20 and 40 weeks increase was up to 219% in the LTP and 460% in the STP group (p<0.02). Comparable results concerning PFWD were obtained in the two groups. Both treatments were well tolerated. No side effect was observed. Local effects were observed in 8.5% of the treated subjects in the LTP and 4% in the STP. The average cost of the LTP protocol was 8786 Euro. For STP the costs was 946 (10.8% of LTP). For both protocols the cost of the infusion was 24% of the total for the LTP and 35% in the STP. Therefore 75% of the cost is not drug-related. CONCLUSIONS: In conclusion between-group-analysis favours STP considering walking distance and costs. Results indicate good efficacy and tolerability of PGE1 treatment particularly STP.

Alprostadil↗
PubMed2002

Out of a recent CVI consensus: some features of a basic statement.

In March 1997 at the Abbaye des Vaux de Cernay, France, a multidisciplinary meeting of venous specialists, to do guidelines on venous management was held. Subsequently the faculty members revised the document and a consensus statement was published in Circulation, in November 2000, based on wide-ranging and authoritative research into the investigation of chronic venous insufficiency (CVI). The statement gives information on the epidemiology and pathophysiology of CVI including the changes in the major veins as well as in the microcirculation and the associated hematological changes. It sets out the methods used for morphologic and hemodynamic investigations into venous disease and for the study of the microcirculation stating their usefulness and limitations, and indicating their place in clinical practice and research. A section deals also with the rare venous malformations. It concludes with an application of the methods in the investigation on CVI based on the CEAP classification that gives a uniform way of reporting venous disorders. The document is intended both for the clinician and the researcher. A shortened version appears below.

Chronic Disease↗
PubMed2002

Spectrum and prevalence of prothrombotic single nucleotide polymorphism profiles in the Greek Cypriot population.

BACKGROUND: This study was performed to establish the allele, genotype and genotype combination/SNP (single nucleotide polymorphism) profile frequencies in the general population of Cyprus for 6 genes implicated in thrombotic disorders. The genes with their respective functional polymorphisms were the following: factor V (G1691A), prothrombin/factor II (G20210A), methylenetetrahydrofolate reductase (C677T), platelet glycoprotein receptor IIIa (P1A1/A2), b-fibrinogen (G/A-455) and plasminogen activator inhibitor-type 1 (4G/5G). METHODS: DNA samples from 121 unrelated individuals were used for this epidemiological study. The polymerase chain reaction followed by restriction digestion were used to genotype the 6 different polymorphic loci. Allele and genotype frequencies were established and shown to be in Hardy-Weinberg equilibrium. RESULTS: Mutant allele frequencies for the 6 genes were as follows: factor V-4%, prothrombin-2%, methylenetetrahydrofolate reductase -39%, platelet glycoprotein receptor IIIa-16%, beta-fibrinogen-17% and plasminogen activator inhibitor - type 1-46%. Combined defects occurred which may increase the risk for vascular events, 33% of individuals (39/118) had 3 or more of the above mutations. CONCLUSIONS: As in other European populations, prospective case-control studies to estimate the risk for deep vein thrombosis (DVT) and ischemic episodes with respect to genetic and environmental risk factors should be performed. Thrombophilia screening should be applied for primary and secondary prevention of thrombotic episodes in susceptible individuals on the island of Cyprus. Individuals targeted for such screening include those with the following: a positive family history for thrombosis; a previous DVT or other ischemic episode; prior exposure to circumstantial risk factors and in the presence of echolucent plaques.

Adult↗
PubMed2002

Association of the HLA antigens with early atheromatosis in subjects with type 2 diabetes mellitus.

BACKGROUND: Inflammation plays an important role in the pathogenesis of atherosclerosis. The major histocompatibility complex, as expressed by the human leukocyte antigens (HLA) is considered to regulate the immune response. The aim of this study was to investigate the association of the HLA antigens with vascular remodeling estimated by the carotid intima-media thickness (IMT) in subjects with type 2 diabetes mellitus (DM). METHODS: We evaluated 197 patients with type 2 DM, 80 males and 117 females, mean age 61.8+/-7.8 years, with no history of cardiovascular events. The presence of other major cardiovascular risk factors was recorded. The currently identified HLA class I (-A, -B, -Cw) and class II (DR, -DQ) antigens were studied by a classical 2 step microlymphocytotoxic technique in peripheral blood T and B lymphocytes. Measurements of the IMT were performed in the right and left common carotid arteries, 15-20 mm proximal to the dilatation of the carotid bulb in an end-diastolic "frozen" and magnified B-mode ultrasonographic image. Glycosylated hemoglobin A1c (HbA1c) and C-reactive protein (CRP) were also measured. The results are presented as mean +/-1 standard deviation. RESULTS: Regarding the HLA phenotypes in the final analysis we tested a total of 24 HLA antigens that exhibited a frequency of at least 5% in our diabetic population. Only HLA A3 was found to be significantly associated with the carotid IMT. Forty-nine (24.9%) diabetics were HLA A3 positive (group A), while 148 (75.1%) were HLA A3 negative (group B) and had mean IMT of 0.89+/-0.16 mm and 0.98+/-0.21 mm, respectively (p<0.01). Also the two groups differed significantly in respect to CRP, with group A exhibiting lower serum levels (1.1+/-0.4 mg/dl vs 2.6+/-0.7 mg/dl for group A and B, respectively, p<0.05). However, no differences were observed between the two groups as far as blood glucose control, arterial hypertension and dyslipidaemia were concerned. CONCLUSIONS: Human leukocyte antigen A3 is associated with less vascular damage, as expressed by carotid wall thickness, in subjects with type 2 DM. These subjects may be characterized by a milder inflammatory response, as shown by the lower serum levels of CRP.

Aged↗
PubMed2001

Carotid and femoral ultrasound morphology screening and cardiovascular events in low risk subjects: a 10-year follow-up study (the CAFES-CAVE study(1)).

BACKGROUND: Subclinical arteriosclerotic lesions at the carotid and femoral bifurcations may be related to the occurrence of future cardiovascular events and of occult arteriosclerotic coronary disease. B-mode ultrasound of carotid and femoral arteriosclerotic bifurcation lesions may provide a simple screening method to select asymptomatic subjects at risk of future events. METHODS AND RESULTS: 13221 low-risk, healthy, asymptomatic individuals were included in a 10-year, prospective, follow-up based on carotid and femoral bifurcation morphology defined by B-mode ultrasound. Four classes were considered at inclusion (I: normal wall, II: wall thickening, III: non-stenosing plaques, IV: stenosing plaques). When 10000 subjects (75.6% of included subjects; 6055 males, 3945 females) completed the 10-year follow-up the study was concluded. At 10 years there were 10 events (out of 7989 subjects) in class I and 81 events in II (930 subjects; incidence=8.6%); 239 events were observed in class III (611 subjects; 39.28%) and 381 events (470 subjects; 81.06%) in IV; 61 deaths occurred in classes III+IV (1081 subjects) producing a death rate within these two classes of 5.5% (51 out of 61=81.5% in class IV). The increased event rates in classes III and IV were significant (log rank; P<0.02) in comparison with I and II. CONCLUSIONS: Carotid and femoral morphology identified 2011 subjects (20.1% of the population) in classes II,III,IV including 98.6% of cardiovascular events and deaths in the following 10 years. A higher (P<0.05) rate of progression in classes III and IV in comparison with I and II was also observed. The ultrasound carotid and femoral classification was useful in selecting subjects at very low risk of cardiovascular events (class I), those at limited risk (class II) and a group at moderate risk (class III). A subpopulation at high risk of cardiovascular events (IV) was identified.

Adult↗
PubMed2001

Sympathetic autoregulation in peripheral vascular disease.

BACKGROUND: Lower limb venous pressure increases on dependency, stimulating a local sympathetic axon reflex which triggers precapillary and arteriolar vasoconstriction. The resulting decrease in arterial calf inflow, known as the venoarteriolar response (VAR), is impaired in critical leg ischaemia. The aim of the study was to evaluate the VAR in symptomatic non-critical leg ischaemia and after restoration of leg perfusion following successful revascularization. METHODS: The study included 30 normal subjects, 30 patients with stable intermittent claudication and 30 patients with severe ischaemia who had undergone successful infrainguinal revascularization. In all patients the foot skin blood flow (flux) in the horizontal (HBF) and sitting (SBF) positions was measured using laser Doppler fluxmetry. The VAR was calculated as (HBF - SBF)/HBF x 100 per cent. The pressure that elicited the reflex (pVAR) was evaluated in the horizontal position. RESULTS: The median VAR was significantly lower in patients with stable claudication than in normal subjects or patients following successful revascularization (29.1 versus 59.5 and 63.9 per cent respectively; P < 0.0001). Similar results were obtained for the pVAR (22 versus 45 and 40 mmHg respectively; P < 0.001). There was no difference, however, in either the VAR or pVAR between normal individuals and patients following a successful bypass. CONCLUSION: Patients with claudication had a significant impairment of orthostatic sympathetic autoregulation. After successful revascularization, and in spite of the extensive disease in the receiving circulation, this autoregulation returned to normal. Presented previously to the Vascular Surgical Society in London, November 1997 and published in abstract form as Br J Surg 1998; 85: 557

Aged↗