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At least 793 records · Page 44Linked to original sources
PubMed2006

Invasive assessment of the coronary microcirculation: superior reproducibility and less hemodynamic dependence of index of microcirculatory resistance compared with coronary flow reserve.

BACKGROUND: A simple, reproducible invasive method for assessing the coronary microcirculation is lacking. A novel index of microcirculatory resistance (IMR) has been shown in animals to correlate with true microvascular resistance and, unlike coronary flow reserve (CFR), to be independent of the epicardial artery. We sought to compare the reproducibility and hemodynamic dependence of IMR with CFR in humans. METHODS AND RESULTS: Using a pressure-temperature sensor-tipped coronary wire, thermodilution-derived CFR and IMR were measured, along with fractional flow reserve (FFR), in 15 coronary arteries (15 patients) under the following hemodynamic conditions: (1) twice at baseline; (2) during right ventricular pacing at 110 bpm; (3) during intravenous infusion of nitroprusside; and (4) during intravenous dobutamine infusion. Mean CFR did not change during baseline measurements or during nitroprusside infusion but decreased during pacing (from 3.1+/-1.1 at baseline to 2.3+/-1.2 during pacing, P<0.05) and during dobutamine infusion (from 3.0+/-1.0 to 1.7+/-0.6 with dobutamine, P<0.0001). By comparison, mean values for IMR and FFR remained similar throughout all hemodynamic conditions. The mean coefficient of variation between 2 baseline measurements was significantly lower for IMR (6.9+/-6.5%) and FFR (1.6+/-1.6%) than for CFR (18.6+/-9.6%; P<0.01). Mean correlation between baseline measurements and each hemodynamic intervention was superior for IMR (r=0.90+/-0.05) and FFR (r=0.86+/-0.12) compared with CFR (r=0.70+/-0.05; P<0.05). CONCLUSIONS: Compared with CFR, IMR provides a more reproducible assessment of the microcirculation, which is independent of hemodynamic perturbations. Simultaneous measurement of FFR and IMR may provide a comprehensive and specific assessment of coronary physiology at both epicardial and microvascular levels, respectively.

Adult↗
PubMed2002

Heart rate effect on hemodynamics during mechanical assistance by the intra-aortic balloon pump.

UNLABELLED: Heart rate (HR) has been characterized as an important cardiovascular parameter that affects acute hemodynamic performance of intra-aortic balloon counterpulsation (IABC). However, the effect of HR on hemodynamics during mechanical assistance by the IABC has neither been clarified nor quantified. We sought to evaluate the relationship between IABC and HR and also to examine whether there is a range of HR with optimum hemodynamic response to IABC. METHODS: 20 patients (14 males--6 females, mean age 64.4 +/- 11.4 years) with post-infarction cardiogenic shock undergoing IABC treatment were evaluated. Hemodynamics were recorded for each patient once per day during the assistance period; 131 measurements were taken and thus a wide range of heart rates was obtained (64-141 bpm). The following changes in aortic pressures were used to evaluate acute IABC performance on: a) the maximal increase of diastolic aortic pressure induced by IABC and b) the reduction in systolic and end-diastolic aortic pressure. RESULTS: Non-linear regression analysis and analysis of variance revealed that a significant correlation exists between IABC performance indices and heart rate. At HR<80 bpm, IABC performance tended to be reduced, whereas the increase in HR above 110 bpm resulted in a significant reduction of all IABC performance indices. In contrast, IABC operating at 80-110 bpm resulted in optimum hemodynamic performance. In conclusion, the effect of heart rate on IABC performance is non-linear indicating that IABC may be more effective when operating within 80-110 bpm.

Aged↗
PubMed2003

Regulation of oxygen transport during brain activation: stimulus-induced hemodynamic responses in human and animal cortices.

BACKGROUND: The correlation between regional changes in neuronal activity and changes in hemodynamics is a major issue for noninvasive neuroimaging techniques such as functional magnetic resonance imaging (fMRI) and near-infrared optical imaging (NIOI). A tight coupling of these changes has been assumed to elucidate brain function from data obtained with those techniques. In the present study, we investigated the relationship between neuronal activity and hemodynamic responses in the occipital cortex of humans during visual stimulation and in the somatosensory cortex of rats during peripheral nerve stimulation. METHODS: The temporal frequency dependence of macroscopic hemodynamic responses on visual stimuli was investigated in the occipital cortex of humans by simultaneous measurements made using fMRI and NIOI. The stimulus-intensity dependence of both microscopic hemodynamic changes and changes in neuronal activity in response to peripheral nerve stimulation was investigated in animal models by analyzing membrane potential (fluorescence), hemodynamic parameters (visible spectra and laser-Doppler flowmetry), and vessel diameter (image analyzer). RESULTS: Above a certain level of stimulus-intensity, increases in regional cerebral blood flow (rCBF) were accompanied by a decrease in regional cerebral blood volume (rCBV), i.e., dissociation of rCBF and rCBV responses occurred in both the human and animal experiments. Furthermore, the animal experiments revealed that the distribution of increased rCBF and O2 spread well beyond the area of neuronal activation, and that the increases showed saturation in the activated area. CONCLUSIONS: These results suggest that above a certain level of neuronal activity, a regulatory mechanism between regional cerebral blood flow (rCBF) and rCBV acts to prevent excess O2 inflow into the focally activated area.

Journal Article↗
PubMed2006

Hemodynamic optimization of sepsis-induced tissue hypoperfusion.

Sepsis is associated with cardiovascular changes that may lead to development of tissue hypoperfusion. Early recognition of sepsis and tissue hypoperfusion is critical to implement appropriate hemodynamic support and prevent irreversible organ damage. End points for resuscitation need to be defined and invasive hemodynamic monitoring is usually required. Targets for hemodynamic optimization should include intravascular volume, blood pressure, and cardiac output. Therapeutic interventions aimed at optimizing hemodynamics in patients with sepsis include aggressive fluid resuscitation, the use of vasopressor agents, inotropic agents and in selected cases transfusions of blood products. This review will cover the most important aspects of hemodynamic optimization for treatment of sepsis induced tissue-hypoperfusion.

Biomarkers↗
PubMed1978

Hemodynamic monitoring in patients with hypotension after myocardial infarction. The role of the medical center in relation to the community hospital.

Patients who develop hypotension after acute myocardial infarction are frequently transferred to medical centers for hemodynamic monitoring. To see if this practice is justified, we reviewed our experience with hemodynamic monitoring over a two-year period. Of 40 patients who underwent hemodynamic monitoring for hypotension, 28 were transferred from other institutions. Eleven (39 percent) of these 28 patients had a pulmonary capillary wedge pressure of 16 mm Hg or less. Ten (91 percent) of these 11 survived, compared with one survivor (8 percent) in the 13 transferred patients with a pulmonary capillary wedge pressure of 17 mm Hg or more (P less than 0.001). The pulmonary capillary wedge pressure did not correlate well with the presence of a third heart sound on physical examination or with chest x-ray films. All hypotensive patients with a low pulmonary capillary wedge pressure received fluids to expand the blood volume as their major form of therapy. Thus, hemodynamic monitoring in patients with hypotension clarifies their status regarding blood volume and identifies those who will benefit from expansion of this volume. Transfer of hypotensive patients for hemodynamic monitoring seems justified, as their status regarding volume of blood is frequently difficult to ascertain by noninvasive means.

Adult↗
PubMed2006

Hemodynamic and vascular endothelium function studies in healthy pigs after intravenous bolus infusion of methylene blue.

OBJECTIVE: Clinical benefit of methylene blue (MB) treating NO-induced vasoplegia has been reported in sepsis, systemic inflammatory response syndrome (SIRS) in cardiac surgery and anaphylactic shock, but its safety is sometimes questioned, mainly regarding its hemodynamic effects and the possibility of causing endothelium dysfunction. To examine the nitric oxide plasma levels and cardiovascular effects of the infusion of MB in vivo and its effects on endothelium-dependent and endothelium-independent in vitro vascular relaxation. METHODS: The study protocol included two experimental groups of female pigs: Group I (Control) - the animals (n=6) did not receive MB; Group II (MB)--the animals received 3 mg/kg of MB intravenous bolus infusion. After fifteen minutes of hemodynamic parameter recording the animals were sacrificed by exsanguination, and in vitro studies were conducted using segments of coronary, hepatic, superior mesenteric and renal arteries, to determine the effect of MB on the arterial endothelium function with regard to NO release. Nitric oxide plasma levels (NOx) were measured in each of the experimental groups. RESULTS: The results obtained in the present investigation were: 1) intravenous infusion of MB (3.0 mg/kg) caused no hemodynamic changes; 2) absolute and percent plasma NOx values did not differ between the experimental groups; and 3) in vitro study of vascular relaxation showed no significant difference between groups. These results show that MB intravenous infusion seems to be safe. This finding agrees with data from clinical experiments where MB was used to treat vasoplegic syndrome after cardiopulmonary bypass, systemic inflammatory response syndrome (SIRS) and anaphylaxis. These results were not unexpected because, as in healthy subjects, hemodynamics is only fine tuned and not fully under NO control; therefore, MB inhibiting guanylyl cyclase is not expected to do anything. CONCLUSION: Intravenous use of MB, at the investigated dose, did not cause any abnormal hemodynamic responses or impairment of endothelium-dependent relaxation.

Animals↗
PubMed2004

Relationships between a proprietary index, bispectral index, and hemodynamic variables as a means for evaluating depth of anesthesia in dogs anesthetized with sevoflurane.

OBJECTIVE: To evaluate relationships among various techniques for monitoring anesthetic depth in sevoflurane-anesthetized dogs undergoing orthopedic surgery. ANIMALS: 10 dogs. PROCEDURE: Dogs were medicated with acepromazine (0.05 mg/kg, IM), buprenorphine (0.01 mg/kg, IM), and atropine (0.04 mg/kg, IM). Anesthesia was induced and maintained with sevoflurane. Cardiovascular and respiratory responses were monitored. Anesthetic depth was monitored by use of the bispectral index (BIS), and a proprietary index was used to monitor activity of the autonomic nervous system. RESULTS: A significant decrease in BIS was seen after induction but concurrent changes were not observed for the other techniques. The proprietary index increased significantly after intubation, but no changes were seen for the other techniques. No significant changes were detected during incision or when higher nociceptive stimuli were applied. We did not identify a correlation between BIS and the proprietary index, the proprietary index and hemodynamic variables, or the BIS and hemodynamic variables during induction and maintenance. A significant increase in the proprietary index and BIS was detected at the time of resumption of reflexes. During anesthetic recovery, a correlation was found between the proprietary index and BIS but not between hemodynamic variables and the other techniques. CONCLUSIONS AND CLINICAL RELEVANCE: A significant increase in the proprietary index, but not the BIS or hemodynamic variables, was detected during intubation. Anesthetic induction with sevoflurane did not prevent the sympathetic stimulus attributable to tracheal intubation. Monitoring of hemodynamic variables does not provide sufficient information to allow clinicians to evaluate stress during anesthetic recovery.

Acepromazine↗
PubMed2006

Hemodynamic changes with liver fibrosis measured by dynamic contrast-enhanced MRI in the rat.

PURPOSE: To evaluate the hemodynamic changes of liver cirrhosis in the rat and investigate the relationship between hemodynamic changes and properties of fibrotic change in the liver. MATERIALS AND METHODS: Three rats with cirrhosis induced by thioacetamide (TAA), three with disease induced by carbon tetrachloride (CCl4), and three with no treatment were measured on dynamic MRI using a 1.5T scanner. Compartment and moment analysis were used to quantitate hemodynamic changes. RESULTS: Compartment model analysis showed that increased transition speed from vessels to the liver correlated with grade of liver fibrosis. Moment analysis demonstrated that decrease of area under the curve (AUC), mean residence time (MRT), variance of residence time (VRT), half life (T1/2) and increased total clearance (CL) correlated with grade of liver fibrosis. CONCLUSIONS: Hemodynamic changes in injured fibrotic liver may be influenced by the grade of fibrosis. Compartment model and moment analysis may be useful for evaluating hemodynamic changes in injured liver.

Animals↗
PubMed2003

Effects of perfluorocarbon associated high frequency oscillatory ventilation on hemodynamics and gas exchange in the newborn piglets with respiratory distress.

We sought to know whether there is a further improvement in gas exchange when partial liquid ventilation (PLV) is added to high-frequency oscillatory ventilation (HFOV) in a piglet model of saline lavage-induced acute lung injury. Seven 7-9 day-old newborn piglets of mixed strain were treated with repeated saline lavage to achieve a uniform degree of acute lung injury. Then, HFOV were applied to the subject. Four animals received two consecutive doses (15 mL/kg) of perfluorodecalin at 30-min interval (PFC+HFOV group). The other three animals remained on HFOV alone (HFOV-only group). Repetitive lung lavage led to a significant acute aggravation in both gas exchange and hemodynamic parameters. Subsequent application of HFOV produced a significant rapid recovery in both gas exchange and hemodynamic parameters to near baseline levels. During and after perfluorodecalin dosing, there were no significant changes in gas exchange or hemodynamic parameters over time in both groups, and no significant differences in gas exchange or hemodynamic parameters between groups. We concluded that the addition of 30 mL/kg of perfluorodecalin to HFOV showed no detrimental effect on hemodynamics, but did not produce a significant improvement in gas exchange over a three-hour period.

Animals↗
PubMedDate not supplied

Portal hemodynamics in chronic liver disease.

Portal hypertension is a result of interplay of numerous static and dynamic forces. Portal hemodynamic characterization involves pressure and flow studies which in turn estimate portal pressure. Hepatic venous pressure gradient is the gold standard for determining portal pressure. Portal hemodynamic measurement has helped to understand the pathogenesis and prognosis of chronic liver disease and to define clinically important hepatic venous pressure gradients. Management strategies for ascites and prevention of variceal hemorrhage have been influenced by hemodynamic studies in animals and humans. The hemodynamics in non-cirrhotic portal fibrosis is ambiguous. The role of portal hemodynamic studies outside clinical trials needs further study.

Animals↗
PubMed1999

Advances in continuous, noninvasive hemodynamic surveillance. Impedance cardiography.

In the current climate of shrinking health care reimbursement and increasing importance of patient centered care, impedance cardiography is one method of enhancing quality of patient care and appropriate use of resources. Hemodynamic and thoracic fluid status data may be obtained quickly, accurately, and without risk, providing a global clinical perspective. Patients benefit from the ability to immediately obtain real time hemodynamic data, particularly those patients who otherwise may not be afforded a high level of monitoring or those needing hemodynamic monitoring when assessment and treatment are delayed because of inaccessibility of critical care beds or in the cardiac catheterization laboratory. Application of a technology assessment model to impedance cardiography illustrates the utility of this method of hemodynamic monitoring. Careful review and critique of the literature differentiates the available impedance technologies, supports use in areas not traditionally associated with hemodynamic monitoring, such as the home and emergency department, and validates the use of impedance cardiography in place of, or as an indication for, pulmonary artery catheterization.

Cardiac Output↗
PubMed2005

Effects of different vasopressors on hemodynamics in patients undergoing orthotopic liver transplantation.

BACKGROUND: The hyperdynamic circulatory state in end-stage liver disease is similar to the hemodynamic state in endotoxic shock. Recent research indicated that proper use of norepinephrine (NE) in patients with endotoxic shock could improve the perfusion of visceral organs and raise the survival rate. In this study, dopamine (DA) or NE combined with DA was infused during the orthotopic liver transplantation (OLT) to observe and compare their effects on hemodynamics, oxygenation, and renal function during different stages of the operation. METHODS: Thirty American Society of Anesthesiology (ASA) III-IV patients undergoing OLT were randomly divided into group DA and group NE with 15 patients in each group. Vasopressors were infused after induction of anesthesia. DA was infused in group DA; DA and NE in group NE. Data of hemodynamics, oxygenation and renal function were collected after induction, 1 hour in preanhepatic, anhepatic, neohepatic phase and at the end of operation. RESULTS: Heart rate (HR) and mean arterial pressure (MAP) of the two groups were stable. In anhepatic phase, central venous pressure (CVP), mean pulmonary arterial pressure (MPAP), pulmonary arterial wedge pressure (PAWP), cardiac output (CO), and cardiac index (CI) decreased, whereas systemic vascular resistance (SVR) and systemic vascular resistance index (SVRI) increased significantly (P < 0.05). The hemodynamic variables of group NE were more stable than that of group DA. Pulmonary vascular resistance (PVR), pulmonary vascular resistance index (PVRI), power of hydrogen (pH), and mixed venous oxygen saturation (SvO2) had no significant changes. Oxygen delivery (DO2) and oxygen consumption (VO2) decreased during anhepatic phase (P < 0.05), but lactic acid (LAC) increased since anhepatic phase. Blood urea nitrogen (BUN) maintained relatively stable during different phases. Group NE had more urine output (F = 4.733, P = 0.039). CONCLUSIONS: During OLT, both DA and NE combined with DA can maintain hemodynamics stable, whereas the latter may create better condition. NE has positive effects on maintenance of renal function.

Adult↗
PubMed2006

Abdominal cluster transplantation and management of perioperative hemodynamic changes.

BACKGROUND: Multivisceral transplantation (MTX, or cluster transplantation) is defined as the transplantation of three or more abdominal organs en bloc, namely the liver together with the pancreatoduodenal complex, the stomach as well as the small bowel with/without the right hemicolon. Up to May 1999, only 72 cases were reported to the Intestinal Transplant Registry. Organ cluster transplantation may carry with complex hemodynamic alterations. Based on our experience in two cases of abdominal cluster transplantation, we describe the technical details of multivisceral transplantation and the management of hemodynamic changes. METHODS: A Swan-Ganz catheter was placed to assist in monitoring the patients' hemodynamic status. After the transplantation, the 2 patients were closely observed in the intensive care unit in terms of vital signs;disseminated intravascular coagulation (DIC) including activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), fibrinogen (Fg) and D-dimer, and arterial blood gas; and quantity and characteristics of drainage. Additionally, intra-abdominal hemorrhage was supervised by bedside B-ultrasonography or enhanced computed tomography (CT) examination. Whole blood viscosity was monitored 2 weeks after transplantation. The blood flow of the hepatic artery and portal vein and arterial resistant index were assessed routinely by Doppler ultrasonography. RESULTS: Hemodynamic changes were observed during perioperation. Liver and renal function recovered within one week after transplantation. Enteral feedings and oral intake were gradually increased with a reciprocal decrease in parenteral nutrition. Despite systemic antibiotics were given according to the results of frequent cultures, patient 1 died from cytomegalovirus (CMV) infection 4 months after transplantation and patient 2 died of a systemic sepsis 2 months after the operation. CONCLUSIONS: Many factors contribute to the success of multivisceral transplantation. In order to maintain hemodynamics stable during perioperation, preoperative coagulatory function should be corrected, and stable circulation, serum electrocyte balance, and normal body temperature should be kept during the operation in addition to the treatment of intra-abdominal hemorrhage and making up for the loss of body fluid. However, complications, infection and rejection are barriers for the improvement of graft survival.

Adenomatous Polyps↗
PubMed2006

[CT perfusion in evaluation of cerebral hemodynamics in carotid artery stenosis].

OBJECTIVE: To study the clinical value of multi-slice spiral CT (MSCT) perfusion technique in evaluation of cerebral hemodynamics in patients with severe carotid stenooclusive lesions. METHODS: Twenty-three patients with severe carotid stenosis were enrolled for evaluation of cerebral hemodynamics, including 12 patients with carotid occlusion and 11 with severe carotid stenosis (> 70%). Among them, 16 patients had multiple arterial diseases, including contralateral carotid stenosis, vertebral arteries stenosis, and cerebral arteries stenosis or occlusion. All patients received CT perfusion examination. Ten normal persons received CT perfusion were regarded as the control group. RESULTS: Cerebral perfusion was bilaterally symmetrical in 10 normal persons. While in the patients group, cerebral hemodynamic impairments ipsilateral to the stenosis side were found by CT perfusion in 17 patients, including an delay of time to peak (TTP) (17 patients), increase of cerebral blood volume (CBV) (7 patients), and decrease of cerebral blood flow (CBF) (4 patients). No significant difference was found between occlusion group (n = 8) and stenosis group (n = 9) (P = 0.640), but incidences of hemodynamic impairment were significantly higher in multiple arterial diseases group (n = 14) than single arterial disease group (n = 3) (P = 0.045). CONCLUSION: CT perfusion technique can sensitively reveal the cerebral hemodynamic impairments in patients with severe carotid stenooclusive diseases, and therefore valuable for clinical application.

Adult↗
PubMedDate not supplied

Perioperative hemodynamic study of patients undergoing abdominal surgery using pulse dye densitometry.

BACKGROUND/AIMS: Pulse dye densitometry (PDD) using indocyanine-green (ICG) is a newly developed technique for monitoring cardiac output (CO), cardiac index (CI), circulating blood volume (BV) and ICG elimination rate (K-ICG). We measured hemodynamic changes during the perioperative period in patients undergoing digestive surgery to analyze relationships between hemodynamic changes and surgical procedures, blood loss, water balance and SIRS. METHODOLOGY: Eighty-seven patients who underwent gastrectomy (n=46) and colectomy (n=41) without postoperative complications were enrolled in this study. The corresponding data from 15 patients who underwent laparoscopic cholecystectomy were used as controls. CO, CI, BV and K-ICG were measured by PDD before operation, on the first postoperative day (POD 1), POD 3, POD 7 and POD 14. RESULTS: In all patients, CO and CI increased significantly until POD 3 compared with preoperative levels. BV on POD 1 decreased significantly compared to the preoperative level. K-ICG increased significantly until POD 14. Laparoscopic cholecystectomy resulted in less surgical stress than gastrectomy or colectomy as measured by hemodynamic changes. There were minimal differences in hemodynamics between the gastrectomy and colectomy groups. There were significant negative correlations between intraoperative blood loss and the [POD 1: preoperative values] ratios for CO, CI, BV or K-ICG. There was no correlation between changes in water balance from operation to POD 1 and [POD 1: preoperative value] BV ratio. CONCLUSIONS: An increase in CO and decrease in BV were observed at the early operative stage, especially in patients with systemic inflammatory response syndrome (SIRS). Interestingly, hepatic artery flow volume (K-ICG) remained high until POD 14. It is important to minimize intraoperative blood loss, since it markedly affects postoperative hemodynamics.

Abdomen↗
PubMed1989

Eicosanoids and the hemodynamic course of live Escherichia coli-induced sepsis in baboons.

Time-related changes in eicosanoid release and hemodynamic parameters were characterized in baboons during the early development of sepsis induced by intravenous (i.v.) infusion of live Escherichia coli (4 x 10(10) organisms/kg) in baboons. Plasma levels of thromboxane B2 (TxB2), a stable metabolite of thromboxane A2 (TxA2), rose rapidly in arterial, venous, and pulmonary arterial blood after infusion of live E. coli, attaining maximal increases at 30 min and returning to control values by 60 min. In contrast, plasma concentrations of 6-keto-PGF1 alpha rose slowly after infusion, reaching peak concentrations at 120 min, then slowly returned to control values between 4 and 5 hr after infusion of live E. coli. Hemodynamic values remained stable during the first 2 hr after infusion, although early changes in cellular energy metabolism and incipient hemodynamic failure were inferred from pyrexia, tachycardia, and metabolic acidosis. At 3 hr, signs of further hemodynamic compromise developed, including increased venous PCO2, reduced pulmonary capillary wedge pressure, and reduced stroke volume, followed by gradual increases in systemic and pulmonary vascular resistance. These factors coincided with progressive reductions in cardiac output and deteriorating circulatory efficiency. The time course of events following infusion of live E. coli indicates that alterations in cellular energy provision occurred early (within 1 hr), whereas central hemodynamic parameters decayed much more slowly. Additionally, TxA2 and PGI2 appear related to the early events in the development of sepsis as their release preceded cardiocirculatory failure.

6-Ketoprostaglandin F1 alpha↗
PubMedDate not supplied

Hemodynamic effect of percutaneous transluminal angioplasty for lower limb atherosclerosis. A study based on pulsed Doppler ultrasound flowmetry.

Measurements of ankle pressure index (API) and arterial flow velocity including calculation of pulsatility index (PI) from the common femoral and pedal arteries were performed in 89 limbs of 75 patients before and after percutaneous transluminal angioplasty (PTA) (63 iliac and 26 femoropopliteal). A pulsed wave Doppler ultrasound flowmeter was used. An increase of API at rest of at least 0.15 or the absence of pressure drop after exercise following PTA was used as criteria for a hemodynamically successful angioplasty. In patients with hemodynamically successful PTA of an iliac obstruction PI increased from 4.2 to 8.6 (p less than 0.001); 91 per cent of these patients improved clinically. When iliac angioplasty was hemodynamically unsuccessful, PI remained unchanged; 11 per cent of these patients improved clinically. All limbs with hemodynamically successful PTA of a femoropopliteal obstruction improved clinically and PI increased from 3.1 to 8.7 (p less than 0.001). After hemodynamically unsuccessful femoropopliteal PTA, PI remained unchanged though 25 per cent of these patients improved clinically. These results illustrate that measurement of arterial flow velocity with calculation of PI may be a useful supplement for the functional evaluation of the effect of PTA, since symptomatic response alone may be unreliable.

Aged↗
PubMed1994

[Effect of calcium antagonist (benidipine) and alpha 1 blocker (urapidil) on renal hemodynamic responses to two acute environmental stresses in spontaneously hypertensive rats (SHR)].

Renal hemodynamic responses were studied in spontaneously hypertensive rats (SHR) and Wistar-Kyoto Rats (WKY) to two acute stresses: environmental stress (foot shock (FS) and air jet (AS)). The effects of calcium channel blocker (benidipine) and alpha 1 blocker (urapidil) on these responses were studied using an ultrasonic pulsed Doppler flowmeter. The increments in mean arterial pressure (MAP) and renal vascular resistance (RVR) were greater in SHR during both stresses. On the other hand, the decrease in the renal blood flow (RBF) with these stresses almost disappeared with renal denervation. These renal hemodynamic responses in SHR disappeared with alpha 1 blocker (urapidil), but not with calcium channel blocker (benidipine). The sympathetic nervous system became hyperactive in SHR under environmental stress, Which induced specific renal hemodynamic change. These results suggest that investigations on essential hypertension should focus on clarifying not only systemic hypertensive reaction, but also changes in renal hemodynamics. Furthermore, it is necessary for antihypertensive therapy to take these hemodynamic changes into consideration.

Acute Disease↗