RESUMO
Objective To analyze the effectiveness and safety of chest pain centers in the management of patients with acute chest pain.Methods The clinical data of 315 patients with acute chest pain who presented to the Affiliated Hospital of Chengdu University of Traditional Chinese Medicine from January 2012 to December 2016 were retrospectively analyzed.The chest pain center of our hospital was established in December 2014.A total of 123 patients with acute chest pain who were treated before the establishment of the chest pain were included as the control group.From December 2014 to December 2016,192 patients with chest pain were admitted and included as the observation group.The percentages of acute myocardial infarction and patients receiving emergency intervention(percutaneous coronary intervention,PCI),the door-to-balloon(D to B)time,average length of hospital stay and rates adverse events between the two groups were compared.Results The percentages of acute myocardial infarction among patients with acute chest pain was 75.6％in the control group and 82.3％in the observation group(P=0.027).The emergency PCI rate was 83.9％in the control group and 92.4％in the observation group(P=0.001).The door-to-balloon time was(64.12±34.76)min in the control group and(58.08±16.26)min in the observation group(P=0.025).The average length of hospital stay was(10.09±4.03)days for the control group,and(7.41±3.78)days for the observation group(P=0.025).There was no statistical difference in the incidence of recurrent myocardial infarction between the 2 groups(P＞0.05).The rates of sudden cardiac death,heart failure,cardiogenic shock and adverse events were all significantly higher in the control group(all P＜0.05).Conclusions The establishment of chest pain center provides safer and more effective treatment to patients with acute chest pain.
RESUMO
Objective To determine the hyperelastic constitutive equation of biological soft tissues and study the mechanical responses during the clamping process of biological tissues. Methods The destructive uniaxial tensile test was performed on fresh porcine liver and the uniaxial tension experiment was simulated in ABAQUS. The hyperelastic constitutive equation of porcine liver was determined by comparing the simulation results with the experimental data. Based on this equation, the sharp teeth-shaped and wave-shaped chucks were used to simulate the clamping process. Results The simulation results of the tensile experiment with the 4th-order Ogden model were in good agreement with the experimental data. The results of tissue clamping simulation showed that stress concentration was more likely to occur when the sharp teeth-shaped chuck was adopted. Conclusions The 4th-order Ogden model can be used to describe the hyperelasticity of porcine liver and determine the relevant para-meters. Using the sharp-shaped chuck is more likely to cause tissue clamping damage, and there is a linear relationship between tissue stress and clamping feed distance. These research findings provide references for the design of surgical clamp.