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.
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.
ObjectiveTo explore the effects of metoprolol on hemodynamics of early septic shock patients with myocardial injury.
MethodsWe prospectively recruited 22 septic shock patients with myocardial injury, who were admitted to the ICU of Xiaolan Hospital during March 2014 and February 2015.The metoprolol was injected through central venous catheter to reduce heart rate by 20% from baseline and maintain for 6h.Hemodynamic and oxygen metabolic parameters were collected to establish database.
ResultsHeart rate decreased significantly to (98±18), (95±16) and (92±18) beat/min respectively at 1h, 3h and 6h post-dosing, compared with (125±28) beat/min at pre-dosing (P < 0.05).Cardiac index decreased significantly to (3.2±1.5), (3.3±1.9) and (3.3±1.6) L·min-1·m-2 respectively at 1h, 3h and 6h post-dosing, compared with (3.9±2.5) L·min-1·m-2 at pre-dosing (P < 0.05).The mean blood pressure, central venous pressure, pulmonary artery wedge pressure, pulmonary vascular resistance index, systemic vascular resistance index and stroke volume index showed no significant changes between pre-dosing and post-dosing (all P > 0.05). Lactate concentration decreased significantly to (9.8±4.1) and (8.1±3.6)mmol/L respectively at 3h and 6h post-dosing, compared with (13.4±5.2)mmol/L at pre-dosing (all P < 0.05), but mixed venous oxygen saturation showed no significant changes (P > 0.05).
ConclusionMetoprolol may reduce heart rate and cardiac output in septic shock patients with myocardial injury, without obvious adverse effects on circulatory function and systemic perfusion.
Objective To analyze the effect of monitoring and modulating the portal vein pressure and blood flow during living donor liver transplantation （LDLT） on preventing small-for-size-syndrome (SFSS). Methods Data of forty-four LDLT recipients between Oct.2007 and Oct.2008 were reviewed. Actual graft-to-recipient weight ratio（GRWR）, portal vein flow and pressure during operation and syndrome of SFSS after operation were recorded. The patients received splenectomy or splenic artery ligation according to actual GRWR, portal vein flow and pressure and WBC. Relationships between patients’ GRWR, portal vein flow, portal vein pressure and occurrence of SFSS were analyzed. Results Six patients received splenectomy and 7 patients received splenic artery ligation to decrease the portal vein flow and pressure during the operation. The portal vein flow and pressure decreased after splenectomy （Plt;0.05）. The portal vein pressure decreased （Plt;0.05） and the portal vein flow had no significant change after splenic artery ligation （P＞0.05）. No SFSS occurred after operation. Conclusion Modulation of portal vein flow and pressure by splenectomy or splenic artery ligation during LDLT operation can decrease the portal vein flow and pressure, and which can prevent the incidence of SFSS.
By using noninvasive venous plethysmography, venography and skin morphology, 44 patients (57 limbs) with chronic venous insufficiency (CVI) in lower extremity were studied , and compared with 12 normal subjects (24 limbs). The results showed that dermal nutrient disturbance caused by deep venous insufficiency accounted for 68%, and followed by perforating venous insufficiency was 44%. Furthermore compared venous refill time (VRT), segmented venous capacitancy (SVC) and maximum venous outflow (MVO) of dermal nutrient disturbance with those of exterior normal skin and normal subjects; and compared VRT, SVC, MVO of deep vein 3-4 stage reflux with those of 1-2 stage reflux and normal subjects,the differences were very significant (Ｐ＜0.05). Compared the VRT of perforating incompetence with that of competence (Ｐ＜0.01). Dermal pathology and ultramicrostructure showed that leucocytes trapping in capillary was a cause of microangiopathy. These results suggest that deep vein 3-4 stage reflux followed by calf perforating insufficiency was a main cause for dermal nutrient disturbance; lower extremity VRT reduced obviously and SVC increased significantly were hemodynamic character, leucocytes trapping in capillary was pathology basis of skin damage.
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.
Objective To analyse the characteristic of hemodynamic changes during off-pump coronary artery bypass grafting （OPCAB）. Methods One hundred consecutive patients received OPCAB and the hemodynamic changes were monitored during the grafts was anastomosed. They were anastomosis of the left internal mammary artery （LIMA） to left anterior descending （LAD） in 97 patients, the anastomosis of saphenous vein （SV） or radial artery（RA） to right coronary artery （RCA） including posterior descending artery （PDA） and posterior left branch （PLB） in 84 patients, to left circumflex coronary artery （LCX） in 50 patients, to optuse marginal artery（OM） in 27 patients, to diagonal artery （DG） in 25 patients. The grafts number in each patient was 3. 1±0. 7. Results Hemodynamics changed when LAD and DG were anastomosed with significantly increase of heart rate （HR）, significantly decrease of mean arterial pressure （MAP） and left ventricular stroke work index （LVSWI, P〈0.05）. Hemodynamics changed when LCX,PDA,PLB,OM were anastomosed with significantly increase of HR and center veinous pressure （CVP, P 〈 0. 05）, significantly decrease of MAP, cardiac index （CI）, stroke index （SI）, right ventricular ejection fraction （RVEF）, right ventricular end-diastolic volume （RVEDV）, LVSWI and right ventricular stroke work index （RVSWI,P〈0.05）. Hemodynamics tended to be stable and CI improved at the end of operation. Conclusion There are no or little hemodynamic changes during the LAD and DG were anastomosed in OPCAB, while hemodynamics changed significantly during LCX, PDA, PLB and OM were anastomosed. Hemodynamics become stable and CI improves after operation.
To investigate the biomechanical effects of direct ventricular assistance and explore the optimal loading mode, this study established a left ventricular model of heart failure patients based on the finite element method. It proposed a loading mode that maintains peak pressure compression, and compared it with the traditional sinusoidal loading mode from both hemodynamic and biomechanical perspectives. The results showed that both modes significantly improved hemodynamic parameters, with ejection fraction increased from a baseline of 29.33% to 37.32% and 37.77%, respectively, while peak pressure, stroke volume, and stroke work parameters also increased. Additionally, both modes showed improvements in stress concentration and excessive fiber strain. Moreover, considering the phase error of the assist device's working cycle, the proposed assist mode in this study was less affected. Therefore, this research may provide theoretical support for the design and optimization of direct ventricular assist devices.
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.
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...
