Impaired Hyperemic Response to Exercise Post Stroke

Individuals with chronic stroke have reduced perfusion of the paretic lower limb at rest; however, the hyperemic response to graded muscle contractions in this patient population has not been examined. This study quantified blood flow to the paretic and non-paretic lower limbs of subjects with chronic stroke after submaximal contractions of the knee extensor muscles and correlated those measures with limb function and activity. Ten subjects with chronic stroke and ten controls had blood flow through the superficial femoral artery quantified with ultrasonography before and immediately after 10 second contractions of the knee extensor muscles at 20, 40, 60, and 80% of the maximal voluntary contraction (MVC) of the test limb. Blood flow to the paretic and non-paretic limb of stroke subjects was significantly reduced at all load levels compared to control subjects even after normalization to lean muscle mass. Of variables measured, increased blood flow after an 80% MVC was the single best predictor of paretic limb strength, the symmetry of strength between the paretic and non-paretic limbs, coordination of the paretic limb, and physical activity. The impaired hemodynamic response to high intensity contractions was a better predictor of lower limb function than resting perfusion measures. Stroke-dependent weakness and atrophy of the paretic limb do not explain the reduced hyperemic response to muscle contraction alone as the response is similarly reduced in the non-paretic limb when compared to controls. These data may suggest a role for perfusion therapies to optimize rehabilitation post stroke.     

Comparing subjective and objective assessments of the severity of vibration induced white finger

The present staging of the disease severity of vibration induced white finger (VWF) is based on the patients' symptoms. Forty patients, with a history of VWF, with disease severity stage III or stage IV, on the Taylor-Pelmear scale, were investigated. Total, reactive hyperaemic blood flow to the hands was measured using an isotope limb blood flow (ILBF) technique. Skin blood flow patterns were assessed using a cold provocation test, followed by thermographic assessment of hand rewarming. Thermographic abnormalities were detected in 39 patients (97%). Decreased post-occlusive, reactive hyperaemic blood flow occurred in 29 patients (73%). There was no difference in skin blood flow patterns or in total hand blood flow between the stage III and stage IV groups. Reduction of postocclusive reactive hyperaemic blood flow may be indicative of occlusive lesions of the digital vessels. We conclude that the classification of the severity of VWF using subjective assessment, needs to be augmented by objective evidence of altered blood flow.     

沙格雷酯治疗2型糖尿病伴下肢动脉硬化闭塞症患者的疗效评估

目的:探讨沙格雷酯治疗2型糖尿病伴下肢动脉硬化闭塞症(ASO)患者的临床疗效。方法:选择2014年4月~2015年5月我院2型糖尿病伴下肢ASO患者80例,给予口服沙格雷酯100 mg,3次/日,连续8周,监测治疗前后患肢的症状与体征、双下肢动脉峰值血流速度、血糖、血脂及血液流变学等指标的变化。结果:口服沙格雷酯8周后,患者疼痛感、冷感、间歇性踱行、麻木感及下肢溃疡等主观症状有效率均大于91%,临床总有效率为93.75%。治疗后患者左、右下肢动脉血管直径与治疗前比较,差异无统计学意义(P0.05),但左、右下肢动脉峰值血流速度比治疗前显著降低,差异有统计学意义(P0.05)。治疗后患者的甘油三酯、总胆固醇、低密度脂蛋白、全血高切黏度及全血低切黏度比治疗前降低,差异有统计学意义(P0.05)。结论:沙格雷酯可改善2型糖尿病伴下肢ASO患者的症状,降低双下肢动脉峰值血流速度,临床疗效确切,值得临床推广应用。     

Cerebral perfusion changes in patients with internal carotid artery stenoses after surgical revascularization

Changes of cerebral perfusion and the condition of collateral blood supply in patients with internal carotid artery stenoses may have a prognostic value for effective blood flow restoration after revascularization of the internal carotid arteries (ICAs). To determine the patterns of cerebral perfusion changes in patients with ICA stenoses before and after surgical treatment, a clinical CT perfusion study of 41 patients with moderate to severe ICA stenoses was performed. Perfusion CT (PCT) had been conducted in 17 patients with moderate ICA stenoses (50–69%) and in 24 patients with severe ICA stenoses (70–99%) 3 times: before intervention (balloon angioplasty with stenting or carotid endarterectomy), on the 3rd to 7th day, and within 1 to 3 months after surgery. Scanning was performed at the level of the basal ganglia and semioval centers. In patients without ICA stenosis (control group of 39 individuals), PCT was conducted once. We found that surgical recanalization of the ICA leads to normalization of the cerebral blood flow parameters in the perfusion area of the middle cranial artery, as evidenced by a decrease of MTT and CBV and an increase of CBF to values comparable to those in the control group. However, blood flow restoration in the anterior and posterior watershed areas, which are known to be mostly affected under chronic hypoperfusion conditions, was observed only in patients with a complete circle of Willis (CW) and moderate ICA stenosis. Therefore, severe stenosis (>70%) and the incomplete CW are the prognostic factors for inadequate blood flow restoration after revascularization in patients with ICA stenoses.     

匹伐他汀对Klotho基因敲除杂合子小鼠血管新生的促进作用

目的：探讨匹伐他汀对Klotho基因敲除杂合子小鼠血管新生的促进作用及其作用机制。方法：建立Klotho基因敲除杂合子小鼠（hetero kl＋／-）和同窝出生野生型小鼠（wild kl＋／＋）下肢缺血模型并分为4组：①hetero正常组;②hetero匹伐他汀组;③wild正常组;④wild匹伐他汀组。使用激光多普勒血流测定仪测定klotho（kl＋／-,kl＋／＋）小鼠投药前、下肢缺血手术后双下肢血流。免疫荧光组化SP法计数Klotho（kl＋／-,kl＋／＋）小鼠缺血肢毛细血管数。免疫酶组化直接法计数Klotho（kl＋／-,kl＋／＋）小鼠缺血肢磷酸化Akt阳性细胞数。蛋白印迹杂交方法检测Klotho（kl＋／-）小鼠缺血肢VEGF蛋白表达。结果：匹伐他汀使Klotho（kl＋／-,kl＋／＋）小鼠术后缺血肢血流恢复明显,缺血肢与非缺血肢血流面积比明显增加;匹伐他汀使Klotho（kl＋／-、kl＋／＋）小鼠缺血肢毛细血管密度增加、p-Akt阳性细胞数明显增加;匹伐他汀使Klotho（kl＋／-）缺血肢VEGF蛋白表达增强。结论：匹伐他汀有促进Klotho基因敲除杂合子小鼠血管新生的作用。其作用机制可能是通过VEGF—p—Akt—NO径路实现的。     

Association between coronary lesion severity and distal microvascular resistance in patients with coronary artery disease

Homogeneity of microvascular resistance in different perfusion areas of the same heart is generally assumed. We investigated the effect of the severity of an epicardial stenosis on microvascular resistance in 27 patients with coronary artery disease and stable angina. All patients had an angiographically normal coronary artery, an artery with an intermediate lesion, and an artery with a severe lesion; the latter was treated with angioplasty. In each patient, distal blood flow velocity and pressure were measured during baseline and maximal hyperemia (induced by intracoronary adenosine) using a Doppler and pressure guide wire, respectively. The ratio of mean distal pressure to average peak blood flow velocity was used as an index for the microvascular resistance (MRv). Within patients, the hyperemic MRv was higher in arteries with more severe stenosis (P = 0.021). After percutaneous transluminal coronary angioplasty (PTCA), the hyperemic MRv decreased (pre-PTCA, 2.6 vs. post-PTCA, 1.9 mmHg.cm(-1)s(-1), P < 0.01) toward the value of the reference artery (1.7 mmHg.cm(-1)s(-1); P = 0.67). We conclude that there is a positive association between coronary lesion severity and variability of distal microvascular resistance that normalizes after angioplasty. This study challenges the concept of uniform distribution of hyperemic MRv that is relevant for the interpretation of both noninvasive and invasive diagnostic tests.     

Behavior of calf blood flow in normal subjects and in patients with intermittent claudication during a 24-h time span.

Calf basal resting and reactive hypercemia blood flow were measured at 4-h intervals during a day in fifteen healthy subjects and in fifteen patients with intermittent claudication by means of a venous occlusion plethysmograph. Mathematical-statistical analysis of the data failed to demonstrate circadian periodicity of calf blood flow in healthy subjects, but proved the existence of a 24-h rhythm of calf basal resting and reactive hyperemia blood flow in patients with intermittent claudication. This different behavior of calf blood flow can be understood if one considers that in healthy subjects the voluntary muscles in the extremities have a blood supply which can be instantaneously adjusted over a large area. In patients with peripheral arterial disease, on the other hand, the vascular responses in voluntary muscles of the limbs to various endogenous or exogenous stimuli are impaired and reduced. The circadian rhythm observed in patients with intermittent claudication has early evening peaks and a nocturnal trough with a nadir occurring after midnight and before 0400. This rhythm displays marked similarities with those of all other circulatory values. As to the mechanism of rhythm, it is hard to decide whether or not it has an independent endogenous origin. It is known that many of the circulatory variables are interrelated and that some are clearly related to other circadian rhythms. Perhaps the rhythmic reduction of limb blood flow which occurs during the night is the mechanism underlying the nocturnal pain of subjects with limb ischemia by peripheral arterial disease.     

Intramuscular gene transfer of FGF-2 attenuates endothelial dysfunction and inhibits intimal hyperplasia of vein grafts in poor-runoff limbs of rabbit

We previously demonstrated that sustained disturbance of endothelium-dependent vasorelaxation and poor distal runoff in ischemic limbs were critical factors affecting the neointimal development of autologous vein grafts (VGs). Also, we recently showed the superior therapeutic potential of basic fibroblast growth factor (bFGF/FGF-2) boosted by the recombinant Sendai virus (SeV) for severe limb ischemia compared with that of vascular endothelial growth factor. Here, the effect of FGF-2 on neointimal hyperplasia of VGs was examined in a rabbit model of poor-runoff limbs. Two weeks after initial surgery for the induction of poor-runoff, SeV-expressing human FGF-2 (SeV-hFGF2) or that encoding firefly luciferase (109 plaque-forming units/head) was injected into the thigh and calf muscle. At that time, the femoral vein was implanted in the femoral artery in an end-to-end manner in some groups. FGF-2 gene-transferred limbs demonstrated significantly increased blood flow assessed not only by laser Doppler flow image but also by ultrasonic transit-time flowmeter (USTF). USTF also showed a significant increase in the blood flow ratio of the deep femoral artery to external iliac artery, indicating that collateral flow was significantly restored in the thigh muscles (P < 0.01). Reduction of neointimal hyperplasia was also observed in the VGs treated by SeV-hFGF2; these grafts demonstrated significant restoration of endothelium-dependent vasorelaxation. These findings thus extend the indications of therapeutic angiogenesis using SeV-hFGF2 to include not only limb salvage but also prevention of late graft failure.     

SPECT 对症状性颅内动脉狭窄支架成形术的疗效评价

目的:通过SPECT脑血流灌注显像,对症状性颅内动脉粥样硬化性狭窄行颅内支架成形术,进行血流动力学的疗效评价。方法:对42例症状性颅内动脉粥样硬化性狭窄(狭窄程度>50%)患者,术前通过SPECT,分为低灌注组和正常灌注组。术后3月复查SPECT,做出血流动力学的疗效评价。通过术前及术后1年mRS评分,比较两组的远期疗效。结果:低灌注组发病症状一般为缺血性卒中,正常灌注组一般为TIA(P<0.01)。低灌注组术后血流灌注较术前改善明显(P<0.01)。正常灌注组复发性TIA的发生率较低灌注组高(P<0.05)。低灌注组术前术后mRS评分有统计学差异(P<0.05)。结论:颅内支架成形术可以明确改善颅内低灌注区的血流灌注,对低灌注组术后缺血事件的预防效果好,并有改善神经功能作用。因此,存在颅内低灌注区的患者更具有颅内支架成形术的手术适应症。     

Caloric restriction stimulates revascularization in response to ischemia via adiponectin-mediated activation of endothelial nitric-oxide synthase

Caloric restriction (CR) can extend longevity and modulate the features of obesity-related metabolic and vascular diseases. However, the functional roles of CR in regulation of revascularization in response to ischemia have not been examined. Here we investigated whether CR modulates vascular response by employing a murine hindlimb ischemia model. Wild-type (WT) mice were randomly divided into two groups that were fed either ad libitum (AL) or CR (65% of the diet consumption of AL). Four weeks later, mice were subjected to unilateral hindlimb ischemic surgery. Body weight of WT mice fed CR (CR-WT) was decreased by 26% compared with WT mice fed AL (AL-WT). Revascularization of ischemic hindlimb relative to the contralateral limb was accelerated in CR-WT compared with AL-WT as evaluated by laser Doppler blood flow and capillary density analyses. CR-WT mice had significantly higher plasma levels of the fat-derived hormone adiponectin compared with AL-WT mice. In contrast to WT mice, CR did not affect the revascularization of ischemic limbs of adiponectin-deficient (APN-KO) mice. CR stimulated the phosphorylation of endothelial nitric-oxide synthase (eNOS) in the ischemic limbs of WT mice. CR increased plasma adiponectin levels in eNOS-KO mice but did not stimulate limb perfusion in this strain. CR-WT mice showed enhanced phosphorylation of AMP-activated protein kinase (AMPK) in ischemic muscle, and administration of AMPK inhibitor compound C abolished CR-induced increase in limb perfusion and eNOS phosphorylation in WT mice. Our observations indicate that CR can promote revascularization in response to tissue ischemia via an AMPK-eNOS-dependent mechanism that is mediated by adiponectin.     

Tissue kallikrein and kinin infusion promotes neovascularization in limb ischemia

Adenovirus-mediated kallikrein delivery has been shown to promote blood vessel growth in the limb under both ischemic and normoperfused conditions. Here we investigated whether a continuous supply of kallikrein and kinin peptide can induce neovascularization in a rat model of hindlimb ischemia. Rats underwent femoral artery ligation and localized injection of tissue kallikrein, bradykinin or B1 receptor agonist, followed by infusion of proteins by osmotic minipump. Regional blood flow was monitored weekly by laser Doppler perfusion imaging. Three weeks after surgery, rats receiving kallikrein and kinins showed a significant increase in the perfusion ratio of ischemic vs. normoperfused limb compared to control rats. Similarly, a microsphere assay showed that kallikrein and kinins significantly increased regional blood flow without altering blood pressure. Moreover, kallikrein and kinins significantly augmented capillary and arteriole densities, as quantified by immunostaining with CD-31 and smooth muscle alpha-actin. Both tissue kallikrein and bradykinin increased hemoglobin content in Matrigel implants in mice, providing further evidence of the angiogenic properties. Kinins, when delivered subcutaneously via Matrigel in rats, also increased regional perfusion. This is the first demonstration that local application of tissue kallikrein protein or kinin peptide has therapeutic value in the treatment of ischemic disease by promoting neovascularization.     

Blue laser light increases perfusion of a skin flap via release of nitric oxide from hemoglobin

It has recently been shown that nitrosyl complexes of hemoglobin (NO-Hb) are sensitive to low-level blue laser irradiation, suggesting that laser irradiation can facilitate the release of biologically active nitric oxide (NO), which can affect tissue perfusion. The aim of this study was to evaluate the therapeutic value of blue laser irradiation for local tissue perfusion after surgical intervention. Blood was withdrawn from a rat, exposed to NO and infused back to the same rat or used for in vitro experiments. In vitro, an increase of NO-Hb levels (electron paramagnetic resonance spectroscopy) up to 15 microM in rat blood did not result in the release of detectable amounts of NO (NO selective electrode). Blue laser irradiation of NO-Hb in blood caused decomposition of NO-Hb complexes and release of free NO. Systemic infusion of NO-Hb in rats affected neither systemic circulation (mean arterial pressure) nor local tissue perfusion (Doppler blood flow imaging system). In contrast, a clear enhancement of local tissue perfusion was observed in epigastric flap when elevated NO-Hb levels in blood were combined with local He-Cd laser irradiation focused on the left epigastric artery. The enhancement of regional tissue perfusion was not accompanied by any detectable changes in systemic circulation. This study demonstrates that blue laser irradiation improves local tissue perfusion in a controlled manner stimulating NO release from NO-Hb complexes.     

Physiological and mechanical adaptation of periarticular cancellous bone after joint ligament injury.

The relation between blood flow and bone mineral density (BMD) of periarticular bone was examined in an in vivo model of joint instability. Eighty mature New Zealand White rabbits were randomly assigned to experimental [anterior cruciate ligament transection (ACLX)], sham-operated control, or age-matched normal control groups. Experimental rabbits underwent unilateral transection of the right anterior cruciate ligament, and the nonoperated left [contralateral (Cntra)] limb was a within-animal control. BMD and blood flow to the periarticular bone in the femoral condyles were assessed in each group at 2, 4, 6, 14, and 48 wk postsurgery, using quantitative computed tomography scanning and entrapment of colored microspheres. BMD was significantly lower (5%) in the ACLX compared with Cntra limbs. Periarticular bone blood flow in the ACLX limbs was significantly greater than in the Cntra limb (29%) in the early stages (6 wk) after injury. Up to 48 wk post-ACLX, a significant correlation was found between increased blood flow and decreased BMD in the periarticular bone of the femoral condyles in the ACLX limbs. This correlation suggested that heightened blood flow may be linked to mechanisms of bone adaptation in joints after ligament injury.     

激光多普勒血流仪在断指再植术后血运监测应用的效果研究

目的:为了提高临床断指再植手术效果,分析断指再植术后彩色多普勒血流成像仪的临床应用效果价值。方法:从2016年9月至2017年9月在我院接受断指再植术治疗的60例患者中,采用随机数表法随机将其分为实验组和对照组各30例。实验组:采用激光多普勒血流成像仪监测再植肢体血运;对照组:采用传统方法监测再植肢体血运。探讨断指再植术后彩色多普勒血流成像仪的临床应用价值。结果:研究结果显示,和对照组相比观察组患者断指再植术后血管栓塞率、血管危象发生率明显降低,而断指成活率以及成活再植指术后功能恢复情况则明显增加(P0.05)。结论:将彩色多普勒血流监测应用于断指再植术后,能够无创、实时、灵敏的反应再植指术后的血运情况,有助于及时发现各种不良事件的,提高再植成功率,效果显著,值得推广。     

Limb vasodilation provoked by stimulation of the carotid sinus. Importance of histaminergy in the dog

The vasodilator reflex induced by baroreceptor stimulation was studied on the hindlimbs of the dog. The reflex was induced by norepinephrine (1 microgram/kg) either by intravenous injection or by direct injection into the carotid sinus. In other experiences, the baroreceptor stimulation was obtained by distension of the sinus by rapid injection of 100 ml of physiological serum. The vascular response was studied by recording the hindlimbs blood flow. One of the limbs was previously pretreated by mepyramine and cimetidine (blockage of histaminergic H1 and H2 receptors). During the first minute after the baroreceptor stimulation, blood samples were collected from the venous blood of hindlimbs for histamine assay (fluorometric assay). Our results show: a much lower vasodilation on the limb pretreated by histamine antagonist, a significant increase during the reflex vasodilation of histamine blood levels measured in the efferent blood of hindlimbs. These results, obtained in experimental conditions as physiological as possible (blood perfusion of the limbs with "natural" hemodynamic parameters) permit to conclude that the vasodilation induced by baroreceptor reflex is at least partially histaminergic in the dog.     

Laser angioplasty of peripheral arteries after unsuccessful recanalization of the superficial femoral artery

AIM: To demonstrate the range of applying laser angioplasty after unsuccessful recanalization of the superficial femoral artery (SFA) with conventional interventional techniques. MATERIALS AND METHODS: In a prospective trial in 94 cases with occlusion of the SFA and formerly unsuccessful conventional percutaneous transluminal angioplasty, laser angioplasty for recanalization was applied. The average occlusion length of the SFA was 17.5 cm (range 4-36 cm). The recanalization attempt was made using the crossover technique in 78 patients, in eight patients with the antegrade technique and in another eight patients using the transpopliteal technique. The primary recanalization attempt was performed with Terumo wires (curved and straight) as well as different catheters (Multipurpose/Vertebralis/Cobra). After the unsuccessful recanalization attempt the laser catheter was applied. RESULTS: The application of laser angioplasty demonstrated a successful recanalization of the SFA in 76/94 patients (80.9%). In 18 patients (19.1%) the recanalization was not possible even with percutaneous transluminal laser angioplasty (PTLA). The reason for the unsuccessful PTLA was in 10 cases due to obstructing calcified material, which was resistant to PTLA application. In four cases obstructing calcifications caused the laser catheter to be positioned in subintimal tissue, resulting in perforation of the SFA. In another four patients there was an aberrant anatomy of the SFA which resulted in a direct vessel injury after advancing the laser catheter. After a follow-up period of 12 months primary, primary-assisted and secondary patency rates were 50.0%, 65.8% and 73.7%, respectively. DISCUSSION: In primarily unsuccessful recanalization of the SFA, PTLA allows in 80% of cases a successful recanalization of the SFA. The technical success rate and the patency rate support the application of PTLA.     

Autologous bone marrow cell implantation as therapeutic angiogenesis for ischemic hindlimb in diabetic rat model

The angiogenic effect induced by autologous bone marrow cell implantation (BMCI) was examined in the ischemic hindlimbs of diabetic and nondiabetic rats. Diabetes mellitus was induced by the systemic administration of streptozotocin. We investigated the production of angiogenic factors and endothelial differentiation from bone marrow cells and the native recovery of blood flow in the ischemic hindlimbs. To observe the angiogenic effect induced by BMCI treatment, 6 x 10(7) bone marrow cells were injected intramuscularly at six points into the ischemic limbs, and regional perfusion recovery was evaluated with colored microspheres 2 wk later. No difference was found between diabetic and nondiabetic rats in the release of angiogenic factors or endothelial differentiation from bone marrow cells in vitro. The levels of nitric oxide in plasma were significantly lower, and native perfusion recovery in the ischemic hindlimbs was significantly slower in the diabetic rats than in the nondiabetic rats. However, although perfusion recovery was achieved in the ischemic hindlimbs, there was no significant increase in systemic VEGF after BMCI treatment in either the diabetic or nondiabetic rats. Therefore, therapeutic angiogenesis induced by BMCI could be a safe and effective treatment for ischemic limb disease in diabetic patients.     

髓内钉固定联合骨水泥填充治疗四肢骨干转移癌伴病理性骨折的临床研究

目的:研究髓内钉固定联合骨水泥填充治疗四肢骨干转移癌伴病理性骨折的临床疗效。方法:选取2009年1月到2014年1月我院收治的四肢骨干转移癌伴病理性骨折患者90例,所有患者均给予髓内钉固定联合骨水泥填充进行治疗。应用视觉模拟评分法(VAS)评定术前、术后患者的疼痛情况,应用Enneking评分来评价患者的肢体功能,应用Kanofsky评分法评价患者的生活质量。结果:所有患者均成功随访,随访时间为10-48个月,平均随访时间为(33.8±2.5)个月。所有患者围手术期均无感染或者其他并发症。术后VAS评分、Enneking评分以及Kanofsky评分均显著优于手术前,比较差异具有统计学意义(P0.05);Enneking评分显示,32例优,34例良,22例中,2例差,优良率为73.3%。结论:髓内钉固定联合骨水泥填充治疗四肢骨干转移癌伴病理性骨折疗效确切,能显著改善肢体功能,减轻患者疼痛,提高患者的生活质量。     

The role of perfusion washout in limb revascularization procedures

Amputated rat hindlimbs were subjected to either normothermic (26 degrees C) or hypothermic (4 degrees C) ischemia. Experimental limbs had their microcirculation washed out (either before or after the ischemic insult) with a physiologic acellular plasma substitute previously reported to enhance flap survival following extended periods of warm ischemia. Control limbs were not washed out; i.e., stagnant blood remained in these limbs. Following the ischemic interval, amputated limbs were replanted. Monastral blue B, a colloidal pigment capable of labeling leaky blood vessels, was administered systemically to all rats just prior to vascular declamping. Limb biopsies of skin and muscle were harvested 30 minutes following revascularization in order to assess Monastral labeling and, therefore, the functional integrity of the microcirculation. Results confirm that stagnant blood under conditions of warm ischemia is detrimental to the functionality of the microcirculation in both skin (p less than 0.03) and muscle (p less than 0.007). Accordingly, perfusion washout, when performed prior to the ischemic period, enhances limb survival following 6 hours of warm ischemia (p less than 0.01). Hypothermia protects against the detrimental effects of stagnant blood; perfusion offers no benefit if hypothermic conditions prevail. Physiologic mechanisms responsible for these findings are discussed.     

Myocardial blood volume and coronary resistance during and after coronary angioplasty

Animal experiments have shown that the coronary circulation is pressure distensible, i.e., myocardial blood volume (MBV) increases with perfusion pressure. In humans, however, corresponding measurements are lacking so far. We sought to quantify parameters reflecting coronary distensibility such as MBV and coronary resistance (CR) during and after coronary angioplasty. Thirty patients with stable coronary artery disease underwent simultaneous coronary perfusion pressure assessment and myocardial contrast echocardiography (MCE) of 37 coronary arteries and their territories during and after angioplasty. MCE yielded MBV and myocardial blood flow (MBF; in ml · min(-1) · g(-1)). Complete data sets were obtained in 32 coronary arteries and their territories from 26 patients. During angioplasty, perfusion pressure, i.e., coronary occlusive pressure, and MBV varied between 9 and 57 mmHg (26.9 ± 11.9 mmHg) and between 1.2 and 14.5 ml/100 g (6.7 ± 3.7 ml/100 g), respectively. After successful angioplasty, perfusion pressure and MBV increased significantly (P < 0.001 for both) and varied between 64 and 118 mmHg (93.5 ± 12.8 mmHg) and between 3.7 and 17.3 ml/100 g (9.8 ± 3.4 ml/100 g), respectively. Mean MBF increased from 31 ± 20 ml · min(-1) · g(-1) during coronary occlusion, reflecting collateral flow, to 121 ± 33 ml · min(-1) · g(-1) (P < 0.01), whereas mean CR, i.e., the ratio of perfusion pressure and MBF, decreased by 20% (P < 0.001). In conclusion, the human coronary circulation is pressure distensible. MCE allows for the quantification of CR and MBV in humans.