The hemodynamics changes of the common carotid arteries in 10 SD rats were measured with a color doppler flowmetry in an attempt to define the changes resulting from end-to-end anastomosis. The left common carotid arteries were divided and followed by end-to-end anastomosis. The systolic mean peak velocities in the left arteries were measured at the proximal, distal and anastomotic sites and in the right intact arteries as well at 6, 12, 24, 48, 72 and 120 hours after repair. The percentage of area reduction at anastomosis was calculated from these data. The results indicated that the systolic mean peak velocity at the anastomotic sites was significantly increased as compared to the velocity at the proximal, distal and contralateral sites (P lt; 0.05). The velocity at the distal sites was significantly lower than that from the proximal and contralateral sites (P lt; 0.05), the mean percentage of the reduction was 33.18% and 33.33%, respectively. From 6 hours to 120 hours after anastomosis of arteries there was various degree of narrowing at the site of anastomosis. The mean per cent of stenosis was 42.48%. It was concluded that from 6 to 120 hours after end-to-end anastomosis of the small arteries, the velocity at the anastomotic site was increased as compared to the velocities at pre- and post-anastomotic sites. The increase of velocity at the site of anatomosis was caused by stenosis at the anastomosis.
ObjectiveTo investigate the expression of tumor necrosis factor α(TNF-α ) in isolated rat heart at different time points after myocardial hypoxia/reoxygenation.
MethodsThe isolated langendorff perfused rat heart model was established. Forty-eight SD rats were randomly divided into four groups: a sham group, hypoxia/reoxygenation groups including a H/R 0.5 h group, a 1 h group and a 2 h group. The heart rate(HR), the 1eft ventricular development pressure(LVDP), maximal rates of increase/decrease of the left ventricular pressure(±dp/dtmax) were continuously recorded. The concentrations of TNF-α and creatine kinase-MB(CK-MB) in myocardium, mRNA expression of TNF-α in myocardium were tested. Ultra structure of myocardium was observed under electron microscope.
ResultsThe levels of LVDP, ±dp/dtmax, and HR of hypoxia/reoxygenation group were significantly lower than those in the sham group(P<0.05).The levels of TNF-α and CK-MB and the expressions of TNF-α at mRNA level in the hypoxia/reoxygenation group were higher than those in the sham group(P<0.05).There were significant differences in the above parameters among the H/R 0.5 h group, the 1 h group, the 2 h group(P<0.05).The concentrations of TNF-α and CK-MB, the mRNA expression of TNF-α were higher in the I/R 2 h group than those in the other two groups.
ConclusionThe high expression of TNF-α in myocardium after myocardial hypoxia/reoxygenation in rats is related to the degree of myocardium damage and may lead to myocardial injury.
Objective To investigate the hemodynamic performance of valved bovine jugular vein conduits (BJVC) for right ventricular outflow tract reconstruction in canine model. Methods The BJVC that were treated with the glutaraldehyde were implanted between the pulmonary artery and right ventricle in seven young canines. Right ventricular and pulmonary artery pressures were measured directly before and after the implantation. Hemodynamic evaluations were carried out by echocardiography and cardiac catheterization after the implantation. Results Seven canines were survival one year after the implantation. The pulmonary artery pressures (including systolic pressure, diastolic pressure and mean pressure) had not significantly changed after reconstruction with the conduits. The right ventricular diastolic pressures had not increased after the reconstruction, but the right ventricular systolic pressure and mean pressure had increased. One year later, the echocardiography showed valve motion with no obvious thickening of the leaflets. No graft kinking or obvious regurgitation of the valve was observed. Cardiac catheterization and angiography showed that the pressure gradients between the right ventricle and the conduits varied from 3 to 19mmHg, the diastolic pressures in the conduits were higher than that of right ventricle((Plt;)0.01), and the conduits and pulmonary arteries had no obvious obstruction. Conclusion The glutaraldehyde-fixed bovine jugular vein conduit has good hemodynamic performance in the pulmonary circulation.
Objective To explore the influence of dexmedetomidine on wake-up test during spinal orthopaedic surgery. Methods All 80 patients taking spinal orthopaedic surgery were randomly divided into the trial group and the control group, with 40 cases in each group. The endotracheal intubation anesthesia was adopted in both groups with same anesthesia induction. Additionally, dexmedetomidine 0.8 μg/ (kg·h) was infused within 10 min in the trial group before anesthesia induction, and then another 0.5 μg/ (kg·h) was also infused from the intraoperation to suture of incision. For the control group, the same amount of normal saline was infused, and all the narcotics were stopped pumping 15 min before the wake-up test, but then were continued pumping after the wake-up test. Finally, the following indexes were analyzed: wake-up time, wake-up quality, hemodynamic changes at the time of 15 min before wake-up (T1), recovery of spontaneous breathing (T2), wake-up (T3) and 15 min after wake-up (T4), dosage of narcotics, and the incidence of adverse events. Results There was no significant difference in the operation time before wake-up between the two groups (P=0.07). For the trial group, the dosage of sevoflurane (P=0.03) and sufentanil (P=0.00) used before wake-up was significantly lower, the wake-up time (P=0.04) and bleeding amount during wake-up (P=0.00) were significantly less, the wake-up quality (P=0.03) was significantly higher, the blood pressure (P=0.00) and heart rate (P=0.00) when wake-up were significantly lower, and the incidence of adverse events (P=0.04) was significantly lower, compared with the control group. Conclusion Dexmedetomidine adopted in spinal orthopaedic surgery can significantly improve patient’s wake-up quality, shorten wake-up time, reduce bleeding amount when wake-up and adverse events after wake-up, and maintain the hemodynamic stability, so it has better protective effects.
fter fracture of femoral neck , the head is often encountered ayascular necrosis. It was not clearwhether the causes of the necrosis was due to injury of the artery or stagnation of venous return orboth. We had observed the hmeodynamics of the blood circulation of both fermoral head of both sides in 27 cases of subcapital fracture by E. C. T. (Emission Computerized Tomography). The resultsshowed that either old, fresh, or heal fractures showed stagnation of venous return. There wasoblite...
Abstract: Objective To investigate the in vivo effective orifice area (EOA) and whether prosthesispatient mismatch (PPM) is going to happen after 19mm St.Jude Regent valves replacement were performed. Methods Twentythree patients with valvular heart diseases were divided into 2 groups according to aortic annular diameter. 19mm St. Jude Regent valves were replaced in aortic valve place (Regent valve group), and 21mm other doubleleaflet mechanical valves were replaced in aortic place (other valves group). All of the operations were accomplished under cardiopulmonary bypass in West China Hospital. All of the patients were followed up in 3 to 6 months after their surgery processes. Color Doppler echocardiography was used to measure the hemodynamic parameters in their followup. Then left ventricular mass (LV mass), EOA and effective orifice area index (EOAI) etc. were calculated and compared by using SPSS 12.0. Results No cardiac episodes were detected during the perioperative period and 36 months after operation. LVmass reduced in 36 months after operation in both groups. No statistical significance of EOA, EOAI and LVmass reduction were detected between the two groups. Conclusions (1)The EOA and in vivo hemodynamic effects of 19mm Regent valve are similar to 21mm other double leaflet mechanical valve. (2)It is safe to use 19mm Regent valve in those patients whose aortic annular diameter are small and need double valve replacement. Using 19mm Regent valve will not cause short time cardiac episodes and PPM. (3)More further works should be done to make sure what is the standard of PPM in Chinese people, such as enlarging the patients number and prolonging the followup time. (4) Further clinical and followup works should be done to make St.Jude Regent valve’s feature out.
The effcet of topical timolol maleate 0.5% on the coroidal circulation was investigaed in 22 normal subjects using the color Doppler,with one eyes as the timolo-treated eye and the contralateral eye as the auto-control eye in each individual.The result showed that,of the 2 groups of eyes,there was a sighificant increase in time average maximum velocity(TAMX),systolic peak velocity(Vs),and distolic velocity(Vd) in timolol-treated eyes.The resistance index in timolol-treated eyes was lower than in the control eyes(p＜0.05). Significant linear correlation in the timolol-treated eyesfound between perfusion and TAMX.It is thought that the increase in volumetric blood flow rate by timolol is due to two concurrent processes:1.an indrect effect on the choroidal circulation through the increase in perfusion pressure; 2.a dirct effect on choroidal vessels resulting from action of drug on adrenergic receptors that is present in the choroidal vasculature.
（Chin J Ocul Fundus Dis,1996,12: 83- 85）
The implantation of biventricular assist device (BiVAD) is more challenging than that of left ventricular assist device for the interaction in the process of multiple input and output. Besides, ventricular assist device (VAD) often runs in constant speed (CS) mode in clinical use and thus BiVAD also faces the problems of low pulsation and imbalance of blood volume between systemic circulation and pulmonary circulation. In this paper, a delay assist mode for a VAD by shortening the support time of VAD was put forward. Then, the effect of the delay mode on cardiac output, pulsation and the function of the aortic valve was observed by numerical method and the rules of hemodynamics were revealed. The research showed that compared with VAD supported in CS mode, the VAD using delay mode in systolic and diastolic period proposed in this paper could meet the demand of cardiac output perfusion and restore the function of the arterial valves. The open ratio of aortic valve (AV) and pulmonary valve (PV) increased with the time set in delay mode, and the blood through the AV/PV helped to balance the left and the right cardiac volume. Besides, delay mode also improved the pulsation index of arterial blood flow, which is conducive to the recovery of the ventricular pulse function of patients.
Objective To observe the effect of ophthalmotonus intervention on ocular hemodynamics in patients with ischemic ophthalmopathy (IOP). Methods 106 IOP patients (106 eyes) were enrolled in this study, including 74 eyes with nonarteritic anterior ischemic optic neuropathy (NAION), 20 eyes with retinal artery occlusion (RAO) and 12 eyes with ocular ischemia syndrome (IOS). The patients were randomly divided into ophthalmotonus intervention group and control group. There were 37 NAION eyes, 10 RAO eyes and six IOS eyes in each group. The patients of ophthalmotonus intervention group received lowering intraocular pressure treatment in addition to the basic therapy to reduce the intraocular pressure to le;12 mm Hg (1 mm Hg=0.133 kPa) or decreased by 7-8 mm Hg, or in a 20%-30% reduction. The patients of control group avoided lowering intraocular pressure treatment. The arm-retinal circulation time (A-RCT) and the peak systolic velocity (PSV), end diastolic velocity (EDV) and resistance index (RI) of ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (PCA) before and one week after treatment were comparatively analyzed by fluorescence fundus angiography (FFA) and color Doppler flow imaging. Results The differences of A-RCT before treatment in ophthalmotonus intervention group and control group in NAION, RAO and IOS patients were not statistically significant (t=0.869, 0.119, 0.000; P＞0.05). The differences of PSV (OA:t=0.586, 0.040, 0.067; CRA:t=0.285, 0.057, 0.775; PCA:t=0.658, 0.653, 1.253), EDV (OA:t=0.274, 0.080, 0.093; CRA:t=0.781, 0.077, 0.277; PCA:t=0.200, 0.209, 0.299) and RI (OA:t=0.121, 0.153, 0.138; CRA:t=0.172, 0.242, 0.642; PCA:t=1.053, 1.066, 0.266) of OA, CRA and PCA before treatment in ophthalmotonus intervention group and control group were not statistically significant (P＞0.05). Compared with control group, A-RCT shortened obviously (t=2.573, 2.236, 2.607; P＜0.05) in ophthalmotonus intervention group one week after treatment. Compared with control group, PSV (OA:t=2.367, 2.368, 2.267; CRA:t=0.775, 1.927, 2.775; PCA:t=2.253, 2.353, 2.353) and EDV (OA:t=2.303, 2.236, 2.503; CRA: t=2.277, 2.377, 2.577; PCA:t=2.299, 2.399, 2.299) of OA, CRA and PCA increased obviously (P＜0.05), RI of OA, CRA and PCA decreased obviously (OA:t=2.238, 2.387, 2.228; CRA:t=2.342, 2.442, 2.542; PCA:t=2.266, 2.366, 2.266; P＜0.05) one week after treatment in treatment group. Conclusion Ophthalmotonus intervention can improve the ocular hemodynamics in IOP patients.
To explore the influence of bionic texture coronary stents on hemodynamics, a type of bioabsorbable polylactic acid coronary stents was designed, for which a finite element analysis method was used to carry out simulation analysis on blood flow field after the implantation of bionic texture stents with three different shapes (rectangle, triangle and trapezoid), thus revealing the influence of groove shape and size on hemodynamics, and identifying the optimal solution of bionic texture groove. The results showed that the influence of bionic texture grooves of different shapes and sizes on the lower wall shear stress region had a certain regularity. Specifically, the improvement effect of grooves above 0.06 mm on blood flow characteristics was poor, and the effect of grooves below 0.06 mm was good. Furthermore, the smaller the size is, the better the improvement effect is, and the 0.02 mm triangular groove had the best improvement effect. Based on the results of this study, it is expected that bionic texture stents have provided a new method for reducing in-stent restenosis.
