Objective To determine the effect of the phosphodiesterase-5 inhibitor sildenafil compared with placebo on exercise capacity and clinical status in HFPEF. Design Multicenter, double-blind, placebo-controlled, parall... Objective To determine the effect of the phosphodiesterase-5 inhibitor sildenafil compared with placebo on exercise capacity and clinical status in HFPEF. Design Multicenter, double-blind, placebo-controlled, parallel-group, randomized clinical trial of 216 sta- ble outpatients with HF, ejection fraction ≥ 50%, elevated N-terminal brain-type natriuretic peptide or elevat- ed invasively measured filling pressures, and reduced exercise capacity. Participants were randomized from October 2008 through February 2012 at 26 centers in North America. Follow-up was through August 30, 2012.展开更多
Background Heart failure （HF） is a common disease with complex pathophysiological causes. The diagnosis of HF commonly relies on comprehensive analyses of medical history and symptoms, and results from echocardiogra...Background Heart failure （HF） is a common disease with complex pathophysiological causes. The diagnosis of HF commonly relies on comprehensive analyses of medical history and symptoms, and results from echocardiography and biochemical tests. Galectin-3, a rela-tively new biomarker in HF, was approved by the US Food and Drug Administration in 2010 as a marker in the stratification of risk for HF. We assessed galectin-3 as a biomarker for HF diagnosis in patients with preserved ejection fraction （pEF） and compared its performance with that of B-type natriuretic peptide （BNP）. Methods Thirty-five pEF patients with HF （HFpEF group） and 43 pEF patients without HF （control group） were enrolled. Plasma levels of galectin-3 and BNP in HFpEF and control subjects were determined. Sensitivity, specificity, pre dictive values, and accuracy of galectin-3 and BNP as markers for HF diagnosis were calculated and compared. Results Levels of galec- tin-3 and BNP were 23.09 ±6.97 ng/mL and 270.46 ± 330.41 pg/mL in the HFpEF group, and 16.74 ± 2.75 ng/mL and 59.94 ± 29.93 pg/mL in the control group, respectively. Differences in levels of galectin-3 and BNP between the two groups were significant （P 〈 0.01）. As a bio- marker for HF diagnosis in study subjects, galectin-3 showed sensitivity and specificity of 94.3% and 65.1%, respectively, at a cutoff value of 17.8 ug/mL. BNP showed sensitivity and specificity of 77.1% and 90.7%, respectively, at a cutoff value of 100 pg/mL. Galectin-3 was a significantly more sensitive （P 〈 0.05） but less specific （P 〈 0.01） biomarker compared with BNP. Differences in positive predictive value, negative predictive value, and accuracy between galectin-3 and BNP markers were not significant （P 〉 0.05）. Areas under the receiver operating characteristic curve （95% confidence interval） were 0.891 （0.808-0.974） and 0.896 （0.809-0.984） for galectin-3 and BNP, respec- tively, with no significant difference between the two values （P 〉 0.05）. Co展开更多
Background Postconditioning has been shown to reduce infarct size, ischemic/reperfusion injury and myocardial injury in patients with acute myocardial infarction （AMI） undergoing percutaneous coronary intervention ...Background Postconditioning has been shown to reduce infarct size, ischemic/reperfusion injury and myocardial injury in patients with acute myocardial infarction （AMI） undergoing percutaneous coronary intervention （PCI）. This study tested the hypothesis that postconditioning attenuates the elevation of tumor necrosis factor-a （TNF-a） and improves heart function in patients with AMI after PCI. Methods A total of 75 patients were randomly assigned to 1 of 3 groups： the routine group （n=-26）, in which no intervention was given at the onset of reperfusion; and the Postcon-30s （n=25） or Postcon-60 s （n=24） groups, in which 3 cycles of 30- or 60-second balloon deflation and inflation were repetitively performed. TNF-a serum concentration was measured by ELISA. Global and regional left ventricular systolic function was determined by echocardiography at 1 year. Thirty-four normal controls （NC） were enrolled in the study. Results The TNF-a concentration in patients with AMI was significantly elevated at baseline compared to controls （P 〈0.01）. Concentration levels increased in the routine and Postcon-30s, but not in Postcon-60s group at 7 days （P 〈0.05）. As for linear associations among the three groups, left ventricular ejection fraction （LVEF） and wall motion score index （WMSI） were ranked as follows： Postcon-60s 〉Postcon-30s〉routine （P values all 〈0.05, 65% vs. 57% vs. 52% and 1.10 vs. 1.27 vs. 1.53） after 1 year. More importantly, there was a significant relevance between the soluble TNF-a serum concentration at 7 days and LVEF or WMSI after 1 year （Pvalues all 〈0.0001）. Conclusions Postconditioning, in particular Postcon-60s was associated with long-term cardioprotective effects for inhibition of the inflammatory response and reperfusion injury. The soluble TNF-a serum concentration provided powerful prognostic information of global and regional left ventricular systolic function in patients with AMI.展开更多
Heart failure with preserved ejection fraction(HFpEF)is a clinical syndrome characterized by symptoms and sings of heart failure with elevated left ventricular filling pressures at rest or during exercise.It is the mo...Heart failure with preserved ejection fraction(HFpEF)is a clinical syndrome characterized by symptoms and sings of heart failure with elevated left ventricular filling pressures at rest or during exercise.It is the most common type of heart failure in the elderly and its prevalence increases with age and is higher in females at any given age.HFpEF is frequently accompanied of comorbid conditions such as diabetes mellitus,obesity,atrial fibrillation and renal dysfunction.The diagnosis relies in the integration of clinical information,laboratory data and interpretation of cardiac imaging and hemodynamic findings at rest and during exercise.Conditions that have a specific treatment such as coronary artery disease,valvular disease,cardiac amyloidosis and constrictive pericarditis should be considered and evaluated as appropriate.Aggressive management of comorbidities,optimization of blood pressure control and volume status using diuretics as needed are among the current treatment recommendations.There are no specific therapies that have shown to decrease mortality in HFpEF.In symptomatic patients with history of hospital admission for decompensated heart failure,the implantation of a wireless pulmonary artery pressure monitor should be considered.Finally,given the high mortality of this condition,goals of care discussion should be initiated early and involvement of palliative care medicine should be considered.展开更多
micro RNAs(mi RNAs) are powerful regulators of posttranscriptional gene expression and play an important role in pathophysiological processes. Circulating mi RNAs can be quantified in body liquids and are promising bi...micro RNAs(mi RNAs) are powerful regulators of posttranscriptional gene expression and play an important role in pathophysiological processes. Circulating mi RNAs can be quantified in body liquids and are promising biomarkers in numerous diseases. In cardiovascular disease mi RNAs have been proven to be reliable diagnostic biomarkers for different disease entities. In cardiac fibrosis(CF) and heart failure(HF) dysregulated circulating mi RNAs have been identified,indicating their promising applicability as diagnostic biomarkers. Some mi RNAs were successfully tested in risk stratification of HF implementing their potential use as prognostic biomarkers. In this respect mi RNAs might soon be implemented in diagnostic clinical routine. In the young field of mi RNA based research advances have been made in identifying mi RNAs as potential targets for the treatment of experimental CF and HF. Promising study results suggest their potential future application as therapeutic agents in treatment of cardiovascular disease. This article summarizes the current state of the various aspects of mi RNA research in the field of CF and HF with reduced ejection fraction as well as preserved ejection fraction. The review provides an overview of the application of circulating mi RNAs as biomarkers in CF and HF and current approaches to therapeutically utilize mi RNAs in this field of cardiovascular disease.展开更多
Background Regional ejection fraction （EFR） measured by real-time three-dimensional echocardiography （RT-3DE） provides a novel method for quantifying left-ventricular （LV） regional systolic function. We aimed to...Background Regional ejection fraction （EFR） measured by real-time three-dimensional echocardiography （RT-3DE） provides a novel method for quantifying left-ventricular （LV） regional systolic function. We aimed to explore the diagnostic value of regional ejection fraction （EFR） derived from RT-3DE in detecting LV aneurysms in patients with myocardial infarction. Methods Thirty-eight patients with myocardial infarction were prospectively enrolled and underwent electrocardiography （ECG）, two-dimensional echocardiography （2-DE）, RT-3DE and left ventriculography （LVG）. Subjects with a negative EFR in at least one segment on RT-3DE were considered as having a ventricular aneurysm. We compared the sensitivity, specificity, Youden＇s index, and positive and negative predictive values of ECG, 2-DE and RT-3DE in determining LV aneurysm with detection by LVG. Results On LVG an LV aneurysm was diagnosed in 16 （42.1%） patients. The sensitivity and specificity were 62.5% and 86.4% for ECG, 81.2% and 95.4% for 2-DE, and 100.0% and 90.9% for RT-3DE in diagnosing LV aneurysm. Youden＇s indexes for ECG, 2-DE and RT-3DE were 0.49, 0.77 and 0.91, respectively. Positive and negative predictive values were 76.9% and 76.0% for ECG, 92.9% and 87.5% for 2-DE, and 88.9% and 100.0% for RT-3DE. Conclusions RT-3DE-derived EFR provides a novel, reliable index in the diagnosis of LV aneurysm and has excellent sensitivity and specificity.展开更多
Background Postprandial hypotension （PPH） occurs frequently in elderly people and may lead to syncope, falls, dizziness, weakness, angina pectoris, and stroke. Some studies suggest that the magnitude of the postpran...Background Postprandial hypotension （PPH） occurs frequently in elderly people and may lead to syncope, falls, dizziness, weakness, angina pectoris, and stroke. Some studies suggest that the magnitude of the postprandial fall in blood pressure （BP） is influenced by the rate at which glucose enters the small intestine. We hypothesized that acarbose （α-glucosidase inhibitor）, a hypoglycemic agent that decreases the rate of glucose absorption in the small intestine, would attenuate PPH in the elderly, and would be safe in the treatment. Methods Forty-three elderly in-patients with PPH were recruited. All of them were in relatively stable conditions. They had semi-liquid standard meals without and with acarbose for the two following days： screening day and intervention day. Blood pressure and heart rate （HR） were recorded at baseline and every 15 minutes for 120 minutes using a non-invasive ambulatory blood pressure monitoring system during the study, and ejection fraction （EF） and fractional shortening （FS） were measured by two dimensional echocardiography. Results Compared with the screening day, the falls in systolic, diastolic and mean arterial blood pressure （SBP, DBP, MAP） （all P 〈0.05） were significantly attenuated after taking acarbose during breakfast, so were MAP （P 〈0.05） during lunch, DBP （P 〈0.05） and MAP （P 〈0.05） during supper. The change of HR was not statistically significant after taking acarbose in three meals. EF and FS were positively correlated with the relief rate. The effective power was 63%, and the incidence of adverse drug reaction （ADR） was 9%. Conclusion Acarbose is effective and safe in the treatment of elderly patients with PPH.展开更多
Background: The recanalization of a chronic total coronary occlusion is the possible way to improve left ventricular (LV) function through the recovery of hibernating myocardium. Aim: The aim of this study is to evalu...Background: The recanalization of a chronic total coronary occlusion is the possible way to improve left ventricular (LV) function through the recovery of hibernating myocardium. Aim: The aim of this study is to evaluate the role of 2D speckle tracking in evaluation of the left ventricular (LV) systolic function in chronic total occlusion (CTO) patients before and at 1 day as well as 3 months after percutaneous coronary intervention (PCI). Patients and Methods: A prospective observational study included 40 patients diagnosed with coronary angiography to have a chronic total occlusion. Percutaneous coronary revascularization was performed according to standard practices with the femoral approach. Conventional 2D echocardiography was used to assess LV functions and wall motion abnormalities scoring index (WMAI). Using speckle-tracking echocardiography was to measure global longitudinal strain (GLS) and. Follow-up of patients was done at day 1 and 3 months later after PCI. Results: Forty patients were included in this study, with a mean age of 58.55 ± 7.98 years. GLS and WMAI difference at baseline and follow-up shows a positive correlation with left ventricular ejection fraction (LVEF) changes at baseline and follow-up (p Conclusion: The results of this study provide evidence to support the clinical use of 2D-STE to monitor the early changes of LV function. In patients undergoing CTO revascularization, change in GLS was more sensitive predictors for LV function improvement at 3-month follow-up.展开更多
Cluster warhead dispersing technique is analyzed with gas dynamic theory. It is seen that the front cover opening and two stage dispersing system is suitable for guided sub missiles whose number is not so large. Th...Cluster warhead dispersing technique is analyzed with gas dynamic theory. It is seen that the front cover opening and two stage dispersing system is suitable for guided sub missiles whose number is not so large. The interior ballistic performances of this system are calculated with numerical calculation method. The performances such as the pressure in the pressure chambers and the velocity of the sub missiles are obtained in curve form.展开更多
The ejection velocity of rock fragments during rock burst, one of the important indexes representing the rock burst strength, is used most conveniently in the supporting design of tunnel with rock burst tendency and i...The ejection velocity of rock fragments during rock burst, one of the important indexes representing the rock burst strength, is used most conveniently in the supporting design of tunnel with rock burst tendency and is often determined by means of observation devices. In order to calculate the average ejection velocity of rock fragments theoretically, the energy of rock burst was divided into damage consuming energy and kinetic energy gained by unit volume of rock firstly, and then the rock burst kinetic proportional coefficient η was brought up which could be determined according to the rock-burst damage energy index W_D , at last the expression of the average ejection velocity of rock fragments during rock burst was obtained and one deep level underground tunnel was researched using the mentioned method. The results show that the calculation method is valid with or without considering the tectonic stress of tunnels, and that the method can be a reference for supporting design of deep mining.展开更多
Heart failure with preserved ejection fraction(HFPEF)is common and represents a major challenge in cardiovascular medicine.Most of the current treatment of HFPEF is based on morbidity benefits and symptom reduction.Va...Heart failure with preserved ejection fraction(HFPEF)is common and represents a major challenge in cardiovascular medicine.Most of the current treatment of HFPEF is based on morbidity benefits and symptom reduction.Various pharmacological interventions available for heart failure with reduced ejection fraction have not been supported by clinical studies for HFPEF.Addressing the specific aetiology and aggressive risk factor modification remain the mainstay in the treatment of HFPEF.We present a brief overview of the currently recommended therapeutic options with available evidence.展开更多
文摘 Objective To determine the effect of the phosphodiesterase-5 inhibitor sildenafil compared with placebo on exercise capacity and clinical status in HFPEF. Design Multicenter, double-blind, placebo-controlled, parallel-group, randomized clinical trial of 216 sta- ble outpatients with HF, ejection fraction ≥ 50%, elevated N-terminal brain-type natriuretic peptide or elevat- ed invasively measured filling pressures, and reduced exercise capacity. Participants were randomized from October 2008 through February 2012 at 26 centers in North America. Follow-up was through August 30, 2012.
文摘Background Heart failure （HF） is a common disease with complex pathophysiological causes. The diagnosis of HF commonly relies on comprehensive analyses of medical history and symptoms, and results from echocardiography and biochemical tests. Galectin-3, a rela-tively new biomarker in HF, was approved by the US Food and Drug Administration in 2010 as a marker in the stratification of risk for HF. We assessed galectin-3 as a biomarker for HF diagnosis in patients with preserved ejection fraction （pEF） and compared its performance with that of B-type natriuretic peptide （BNP）. Methods Thirty-five pEF patients with HF （HFpEF group） and 43 pEF patients without HF （control group） were enrolled. Plasma levels of galectin-3 and BNP in HFpEF and control subjects were determined. Sensitivity, specificity, pre dictive values, and accuracy of galectin-3 and BNP as markers for HF diagnosis were calculated and compared. Results Levels of galec- tin-3 and BNP were 23.09 ±6.97 ng/mL and 270.46 ± 330.41 pg/mL in the HFpEF group, and 16.74 ± 2.75 ng/mL and 59.94 ± 29.93 pg/mL in the control group, respectively. Differences in levels of galectin-3 and BNP between the two groups were significant （P 〈 0.01）. As a bio- marker for HF diagnosis in study subjects, galectin-3 showed sensitivity and specificity of 94.3% and 65.1%, respectively, at a cutoff value of 17.8 ug/mL. BNP showed sensitivity and specificity of 77.1% and 90.7%, respectively, at a cutoff value of 100 pg/mL. Galectin-3 was a significantly more sensitive （P 〈 0.05） but less specific （P 〈 0.01） biomarker compared with BNP. Differences in positive predictive value, negative predictive value, and accuracy between galectin-3 and BNP markers were not significant （P 〉 0.05）. Areas under the receiver operating characteristic curve （95% confidence interval） were 0.891 （0.808-0.974） and 0.896 （0.809-0.984） for galectin-3 and BNP, respec- tively, with no significant difference between the two values （P 〉 0.05）. Co
文摘Background Postconditioning has been shown to reduce infarct size, ischemic/reperfusion injury and myocardial injury in patients with acute myocardial infarction （AMI） undergoing percutaneous coronary intervention （PCI）. This study tested the hypothesis that postconditioning attenuates the elevation of tumor necrosis factor-a （TNF-a） and improves heart function in patients with AMI after PCI. Methods A total of 75 patients were randomly assigned to 1 of 3 groups： the routine group （n=-26）, in which no intervention was given at the onset of reperfusion; and the Postcon-30s （n=25） or Postcon-60 s （n=24） groups, in which 3 cycles of 30- or 60-second balloon deflation and inflation were repetitively performed. TNF-a serum concentration was measured by ELISA. Global and regional left ventricular systolic function was determined by echocardiography at 1 year. Thirty-four normal controls （NC） were enrolled in the study. Results The TNF-a concentration in patients with AMI was significantly elevated at baseline compared to controls （P 〈0.01）. Concentration levels increased in the routine and Postcon-30s, but not in Postcon-60s group at 7 days （P 〈0.05）. As for linear associations among the three groups, left ventricular ejection fraction （LVEF） and wall motion score index （WMSI） were ranked as follows： Postcon-60s 〉Postcon-30s〉routine （P values all 〈0.05, 65% vs. 57% vs. 52% and 1.10 vs. 1.27 vs. 1.53） after 1 year. More importantly, there was a significant relevance between the soluble TNF-a serum concentration at 7 days and LVEF or WMSI after 1 year （Pvalues all 〈0.0001）. Conclusions Postconditioning, in particular Postcon-60s was associated with long-term cardioprotective effects for inhibition of the inflammatory response and reperfusion injury. The soluble TNF-a serum concentration provided powerful prognostic information of global and regional left ventricular systolic function in patients with AMI.
文摘Heart failure with preserved ejection fraction(HFpEF)is a clinical syndrome characterized by symptoms and sings of heart failure with elevated left ventricular filling pressures at rest or during exercise.It is the most common type of heart failure in the elderly and its prevalence increases with age and is higher in females at any given age.HFpEF is frequently accompanied of comorbid conditions such as diabetes mellitus,obesity,atrial fibrillation and renal dysfunction.The diagnosis relies in the integration of clinical information,laboratory data and interpretation of cardiac imaging and hemodynamic findings at rest and during exercise.Conditions that have a specific treatment such as coronary artery disease,valvular disease,cardiac amyloidosis and constrictive pericarditis should be considered and evaluated as appropriate.Aggressive management of comorbidities,optimization of blood pressure control and volume status using diuretics as needed are among the current treatment recommendations.There are no specific therapies that have shown to decrease mortality in HFpEF.In symptomatic patients with history of hospital admission for decompensated heart failure,the implantation of a wireless pulmonary artery pressure monitor should be considered.Finally,given the high mortality of this condition,goals of care discussion should be initiated early and involvement of palliative care medicine should be considered.
基金Supported by The European Union,Biomar Ca RE,No.HEALTH-2011-278913
文摘micro RNAs(mi RNAs) are powerful regulators of posttranscriptional gene expression and play an important role in pathophysiological processes. Circulating mi RNAs can be quantified in body liquids and are promising biomarkers in numerous diseases. In cardiovascular disease mi RNAs have been proven to be reliable diagnostic biomarkers for different disease entities. In cardiac fibrosis(CF) and heart failure(HF) dysregulated circulating mi RNAs have been identified,indicating their promising applicability as diagnostic biomarkers. Some mi RNAs were successfully tested in risk stratification of HF implementing their potential use as prognostic biomarkers. In this respect mi RNAs might soon be implemented in diagnostic clinical routine. In the young field of mi RNA based research advances have been made in identifying mi RNAs as potential targets for the treatment of experimental CF and HF. Promising study results suggest their potential future application as therapeutic agents in treatment of cardiovascular disease. This article summarizes the current state of the various aspects of mi RNA research in the field of CF and HF with reduced ejection fraction as well as preserved ejection fraction. The review provides an overview of the application of circulating mi RNAs as biomarkers in CF and HF and current approaches to therapeutically utilize mi RNAs in this field of cardiovascular disease.
文摘Background Regional ejection fraction （EFR） measured by real-time three-dimensional echocardiography （RT-3DE） provides a novel method for quantifying left-ventricular （LV） regional systolic function. We aimed to explore the diagnostic value of regional ejection fraction （EFR） derived from RT-3DE in detecting LV aneurysms in patients with myocardial infarction. Methods Thirty-eight patients with myocardial infarction were prospectively enrolled and underwent electrocardiography （ECG）, two-dimensional echocardiography （2-DE）, RT-3DE and left ventriculography （LVG）. Subjects with a negative EFR in at least one segment on RT-3DE were considered as having a ventricular aneurysm. We compared the sensitivity, specificity, Youden＇s index, and positive and negative predictive values of ECG, 2-DE and RT-3DE in determining LV aneurysm with detection by LVG. Results On LVG an LV aneurysm was diagnosed in 16 （42.1%） patients. The sensitivity and specificity were 62.5% and 86.4% for ECG, 81.2% and 95.4% for 2-DE, and 100.0% and 90.9% for RT-3DE in diagnosing LV aneurysm. Youden＇s indexes for ECG, 2-DE and RT-3DE were 0.49, 0.77 and 0.91, respectively. Positive and negative predictive values were 76.9% and 76.0% for ECG, 92.9% and 87.5% for 2-DE, and 88.9% and 100.0% for RT-3DE. Conclusions RT-3DE-derived EFR provides a novel, reliable index in the diagnosis of LV aneurysm and has excellent sensitivity and specificity.
基金This work was supported by a grant from the National Natural Science Foundation of Hunan Province （No. 05JJ30158）.
文摘Background Postprandial hypotension （PPH） occurs frequently in elderly people and may lead to syncope, falls, dizziness, weakness, angina pectoris, and stroke. Some studies suggest that the magnitude of the postprandial fall in blood pressure （BP） is influenced by the rate at which glucose enters the small intestine. We hypothesized that acarbose （α-glucosidase inhibitor）, a hypoglycemic agent that decreases the rate of glucose absorption in the small intestine, would attenuate PPH in the elderly, and would be safe in the treatment. Methods Forty-three elderly in-patients with PPH were recruited. All of them were in relatively stable conditions. They had semi-liquid standard meals without and with acarbose for the two following days： screening day and intervention day. Blood pressure and heart rate （HR） were recorded at baseline and every 15 minutes for 120 minutes using a non-invasive ambulatory blood pressure monitoring system during the study, and ejection fraction （EF） and fractional shortening （FS） were measured by two dimensional echocardiography. Results Compared with the screening day, the falls in systolic, diastolic and mean arterial blood pressure （SBP, DBP, MAP） （all P 〈0.05） were significantly attenuated after taking acarbose during breakfast, so were MAP （P 〈0.05） during lunch, DBP （P 〈0.05） and MAP （P 〈0.05） during supper. The change of HR was not statistically significant after taking acarbose in three meals. EF and FS were positively correlated with the relief rate. The effective power was 63%, and the incidence of adverse drug reaction （ADR） was 9%. Conclusion Acarbose is effective and safe in the treatment of elderly patients with PPH.
文摘Background: The recanalization of a chronic total coronary occlusion is the possible way to improve left ventricular (LV) function through the recovery of hibernating myocardium. Aim: The aim of this study is to evaluate the role of 2D speckle tracking in evaluation of the left ventricular (LV) systolic function in chronic total occlusion (CTO) patients before and at 1 day as well as 3 months after percutaneous coronary intervention (PCI). Patients and Methods: A prospective observational study included 40 patients diagnosed with coronary angiography to have a chronic total occlusion. Percutaneous coronary revascularization was performed according to standard practices with the femoral approach. Conventional 2D echocardiography was used to assess LV functions and wall motion abnormalities scoring index (WMAI). Using speckle-tracking echocardiography was to measure global longitudinal strain (GLS) and. Follow-up of patients was done at day 1 and 3 months later after PCI. Results: Forty patients were included in this study, with a mean age of 58.55 ± 7.98 years. GLS and WMAI difference at baseline and follow-up shows a positive correlation with left ventricular ejection fraction (LVEF) changes at baseline and follow-up (p Conclusion: The results of this study provide evidence to support the clinical use of 2D-STE to monitor the early changes of LV function. In patients undergoing CTO revascularization, change in GLS was more sensitive predictors for LV function improvement at 3-month follow-up.
文摘Cluster warhead dispersing technique is analyzed with gas dynamic theory. It is seen that the front cover opening and two stage dispersing system is suitable for guided sub missiles whose number is not so large. The interior ballistic performances of this system are calculated with numerical calculation method. The performances such as the pressure in the pressure chambers and the velocity of the sub missiles are obtained in curve form.
文摘The ejection velocity of rock fragments during rock burst, one of the important indexes representing the rock burst strength, is used most conveniently in the supporting design of tunnel with rock burst tendency and is often determined by means of observation devices. In order to calculate the average ejection velocity of rock fragments theoretically, the energy of rock burst was divided into damage consuming energy and kinetic energy gained by unit volume of rock firstly, and then the rock burst kinetic proportional coefficient η was brought up which could be determined according to the rock-burst damage energy index W_D , at last the expression of the average ejection velocity of rock fragments during rock burst was obtained and one deep level underground tunnel was researched using the mentioned method. The results show that the calculation method is valid with or without considering the tectonic stress of tunnels, and that the method can be a reference for supporting design of deep mining.
文摘Heart failure with preserved ejection fraction(HFPEF)is common and represents a major challenge in cardiovascular medicine.Most of the current treatment of HFPEF is based on morbidity benefits and symptom reduction.Various pharmacological interventions available for heart failure with reduced ejection fraction have not been supported by clinical studies for HFPEF.Addressing the specific aetiology and aggressive risk factor modification remain the mainstay in the treatment of HFPEF.We present a brief overview of the currently recommended therapeutic options with available evidence.
