Myocardial contraction fraction by echocardiography and mortality in cardiac intensive care unit patients.

BACKGROUND: The myocardial contraction fraction (MCF) is proposed as an improved measure of left ventricular (LV) systolic function that overcomes important limitations of the left ventricular ejection fraction (LVEF). We sought to determine whether a low MCF was associated with higher mortality in cardiac intensive care unit (CICU) patients. METHODS: We retrospectively analyzed unique Mayo Clinic CICU patients from 2007 to 2018 with MCF calculated as the ratio of the stroke volume to the left ventricular myocardial volume from a transthoracic echocardiogram within 1 day of CICU admission. Multivariable logistic regression analyzed the association between MCF and hospital mortality, after adjustment for LVEF and clinical variables. RESULTS: We included 4794 patients with a mean age of 68.0 ± 14.8 years (37.1% females). The mean MCF was 0.41 ± 0.16, and was lower in the 6.6% of patients who died in the hospital (0.32 ± 0.14 versus 0.42 ± 0.16, p < 0.001). On multivariable analysis, higher MCF remained associated with lower hospital mortality (adjusted OR 0.78 per 0.1 higher, 95% CI 0.69-0.89, p < 0.001), whereas LVEF was not significantly associated with hospital mortality (unadjusted OR 0.91 per 10% higher, OR 95% CI 0.82-1.02, p = 0.09). Patients with MCF <0.2 had the highest in-hospital mortality, and those with MCF ≥0.5 had the lowest in-hospital mortality, irrespective of admission diagnosis or LVEF. CONCLUSIONS: MCF demonstrated a strong, inverse relationship with hospital mortality in CICU patients, even after adjusting for LVEF and clinical variables. MCF can be used to identify prognostically-relevant myocardial dysfunction at the bedside, even among patients with preserved LVEF.

Radial Motion Estimation of Myocardium in Rats with Myocardial Infarction: A Hybrid Method of FNCCGLAM and Polar Transformation.

Ultrasound elastography is a novel approach of evaluating regional myocardial systolic function and detecting infarcted area. This study aims to evaluate the radial motion of myocardial infarction (MI) area in left ventricular parasternal short axis (PSAX) view using a hybrid method of fast normalized cross-correlation and global analytic minimization (FNCCGLAM) and polar transformation. Fifteen rats were randomly selected for sham group, MI group and ischemia-reperfusion (IR) group (N = 5 for each group). The ultrasound radiofrequency data of the PSAX view of rat heart were acquired. After polar transformation of the data, the infarcted myocardium with the change of mechanical property was tracked over one myocardial systolic phase by the proposed method in comparison with fast normalized cross-correlation (FNCC) and dynamic programming analytic minimization (DPAM). To obtain a clear visualization of the myocardium, the inverse polar transformation was performed. The results indicated that the use of FNCCGLAM refined the myocardial displacements to obtain high-quality myocardial elastographic map with a higher contrast-to-noise ratio and dynamically tracked the infarcted myocardial segment with a higher success rate in comparison with FNCC and DPAM. It was found that the radial systolic motion of the infarcted anterior segment in the MI group reduced significantly (p < 0.05) in comparison with the sham group, while the systolic function of that myocardial segment in the IR group recovered at some extent. The results in this study suggest that FNCCGLAM is superior to FNCC and DPAM with the improved accuracy and robustness of motion estimation and has potentials as displacement estimator in ultrasound elastography.

Remifentanil attenuates cardiac dysfunction, lipid peroxidation and immune disorder in rats with isoproterenol-induced myocardial injury via JNK/NF-KB p65 inhibition.

BACKGROUND: Myocardial injury caused by myocardial ischemia (MI) is still a severe condition that can result in apoptosis, oxidative stress, and inflammation. Remifentanil is a selective, ultra-short-acting, µ-opioid receptor agonist opioid. It can improve sinusoidal heart rate patterns in the fetus, for bupivacaine-induced cardiotoxicity, and with lipopolysaccharide (LPS)-induced cardiomyocytes injuries. This study aimed to explore the cardioprotective effects of remifentanil in MI model rats. METHODS: Sprague Dawley (SD) rats were split into five groups at random, including a control group, Isop group, low-dose remifentanil treatment group (10 µg/kg), medium-dose remifentanil treatment group (20 µg/kg), and a high-dose remifentanil treatment group (40 µg/kg). The MI model was achieved by subcutaneously injecting rats with isoproterenol (85 mg/kg) for two consecutive days. With the expression of apoptotic molecules, myocardial systolic function index, inflammation, antioxidant enzymes, and the myocardial enzyme taken into account, the data was analyzed. RESULTS: After treatment with remifentanil, the left ventricular wall thickness (LVWT), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), fraction shortening (FS), and heart rate (HR) were significantly increased in comparison with the Isop group. Creatine kinase-MB (CK-MB), Mb, and cTnl expressions were decreased. Meanwhile, the levels of cleaved caspase-3 and caspase-9 were decreased. Remarkably, the levels of reactive oxidative species (ROS), malondialdehyde (MDA), and lactate dehydrogenase (LDH) were observed to be repressed, while the levels of superoxide dismutase (SOD) was significantly increased. More importantly, the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, IL-6, and interferon (IFN)-γ were decreased. CONCLUSIONS: Remifentanil has significant potential as a therapeutic intervention strategy for ameliorating myocardial injury after MI and these findings provide the rationale for further clinical studies.

Evaluation of left ventricular systolic transmural myocardial dysfunction of maintenance hemodialysis patients using ultrasonic layer‐specific strain technology / 中华超声影像学杂志

Objective To assess the clinical ultrasound value of layer‐specific strain in evaluation of left ventricular systolic myocardial dysfunction of uremia patients after long‐time dialysis at different time . Methods A total of 68 uremia patients accepted maintenance hemodialysis ( M HD ) were enrolled . T he patients were divided into two groups according to the dialysis duration :dialysis time ＜3 years ( group B , n＝31) and dialysis time ≥3 years ( group C , n ＝37) . T he age and sex mached healthy cases were selected as control group ( group A , n ＝ 30 ) . T he standard dynamic two‐dimensional echocardiographic viewes of apical four‐chamber ,three‐chamber ,two‐chamber and the short‐axis view at three levels of mitral valve , papillary muscle and apex were acquired for three cardiac cycles . T he highest value of peak systolic longitudinal strain ( LS ) ,circumferential strain ( CS ) at different levels ,left venrticular global longitudinal strain ( GLS ) and global circumferential strain ( GCS ) were respectively assessed from endocardium ,mid‐myocardium and epicardium using GE EchoPAC workstation . T he comparisons of those parameters were performed among the 3 groups for differences . T he efficacies of GLS and GCS at different myocardial layers in diagdosing the left ventricular systolic function of M HD patients were analyzed by the ROC curve . Results ① Global transmural parameters :compared with those in group A ,the values of GLS at three myocardial layers in both M HD groups were significantly decreased ( all P ＜ 0 .01 ) ,the value of GLS at three myocardial layers in group C was also decreased ,and was statistically different from that in group B ( P＜0 .01) . Compared with those in group A ,the values of GCS at mid‐myocardium in group B and three myocardial layers in group C were also decreased ( all P ＜0 .01) . T here was no significant difference of GCS between group B and C ( P ＞0 .05) . ②Longitudinal transmural parameters at different levels :the values of LS at three myocardial layers of mitral valve ,papillary muscle and apex were decreased in group B and C compared with those in group A ( P ＜0 .05 or P ＜0 .01) ; T he values of LS at three myocardial layers of mitral valve ,papillary muscle and apical levels were also decreased in group C compared with those in group B ( P ＜0 .05 or P ＜0 .001) . ③Short‐axis transmural parameters at different levels :compared with those in group A ,the value of CS at mid‐myocardium of mitral valve level was decreased in group B ( P ＜0 .05) ,the values of CS at three myocardial layers of the mitral valve level and mid‐myocardium of papillary muscle level and apical level were decreased in group C ( P ＜0 .05 or P ＜0 .01) . Besides ,compared with those in group B ,the values of CS at mid‐myocardium and epicardium of mitral valve level were also decreased in group C ( P ＜0 .05) . ④ROC curve showed that determining left ventricular systolic dysfunction in M HD patients using GLS ,GCS at different myocardial layers ,when the area under the curve ( AUC ) of GLS of intima was 0 .851 ,the cut‐off value was －21 .45% ,the sensitivity was 72 .7% ,and the specificity was 93 .3% ; when the AUC of GCS of mid‐myocardium was 0 .683 ,the cut‐off value was －17 .08% , the specificity was 58 .5% , and the specificity was 83 .3% . Conclusions T he left ventricular systolic myocardial function is progressively damaged with the extended dialysis duration time . Ultrasonic layer‐specific strain technology could be used to quantitatively evaluate left ventricular systolic transmural myocardial dysfunction and might contribute to the evaluation of the severity of left ventricular myocardial dysfunction clinically for a more accurate intervention .

Speckle tracking echocardiography to assess regional ventricular function in patients with apical hypertrophic cardiomyopathy.

AIM: To explore regional systolic strain of midwall and endocardial segments using speckle tracking echocardiography in patients with apical hypertrophic cardiomyopathy (HCM). METHODS: We prospectively assessed 20 patients (mean age 53 ± 16 years, range: 18-81 years, 10 were male), with apical HCM. We measured global longitudinal peak systolic strain (GLPSS) in the midwall and endocardium of the left ventricle. RESULTS: The diastolic thickness of the 4 apical segments was 16.25 ± 2.75 mm. All patients had a normal global systolic function with a fractional shortening of 50% ± 8%. In spite of supernormal left ventricular (LV) systolic function, midwall GLPSS was decreased in all patients, more in the apical (-7.3% ± -8.8%) than in basal segments (-15.5% ± -6.93%), while endocardial GLPPS was significantly greater and reached normal values (apical: -22.8% ± -7.8%, basal: -17.9% ± -7.5%). CONCLUSION: This study shows that two-dimensional strain was decreased mainly confined to the mesocardium, while endocardium myocardial deformation was preserved in HCM and allowed to identify subclinical LV dysfunction. This transmural heterogeneity in systolic strain had not been previously described in HCM and could be explained by the distribution of myofibrillar disarray in deep myocardial areas. The clinical application of this novel finding may help further understanding of the pathophysiology of HCM.

Myocardial perfusion before delayed percutaneous coronary intervention is valuable in predicting the systolic function recovery of patients with acute myocardial infarction / 中华医学超声杂志（电子版）

Objective To evaluated the value of myocardial perfusion before delayed percutaneous coronary intervention (PCI) for predicting the recovery of systolic function of patients with acute myocardial infarction (AMI).Methods A total of 64 patients with AMI receiving delayed PCI treatment in the First People's Hospital of Foshan from January 2014 to June 2015 were selected.One day prior to delayed PCI,all of the patients underwent two dimensional strain to measure the longitudinal peak systolic strain (LPSS) of each left ventricular segment and the global longitudinal strain (GLS) of the left ventricle.The myocardial perfusion score (MPS) and the perfusion score index (PSI) were measured by myocardial contrast echocardiography (MCE).Left ventricular myocardial perfusions were classified as good,reduced,or absent.The two dimensional strain measurements were again conducted at 6 months after the delayed PCI to assess LPSS and GLS.The change of GLS and LPSS between one day prior to delayed PCI and six months after delayed PCI was assessed by paired t-test.The differences of LPSS among good,reduced,or absent myocardial perfusion groups were analyzed by one-way ANOVA.LSD-t test was used to compare in pairs of groups that had different values.The correlations between PSI and GLS,MPS and LPSS were assessed by Spearman's rank-correlation test.Results The GLS of all patients were higher at six months after delayed PCI than at one day prior to delayed PCI [(-15.39±7.80)％ vs (-12.44±8.38)％,t=14.398,P ＜ 0.001].The LPSS of myocardial perfusion in good,reduced and absent groups at one day prior to delayed PCI were (-2.64±5.60)％,(-6.19±6.87)％ and (-12.07±5.86)％,respectively.The LPSS of myocardial perfusion in good,reduced and absent groups at six months after delayed PCI were (-2.97 ± 4.93)％,(-11.38± 7.26)％ and (-15.82 ± 5.97)％,respectively.The myocardial LPSS of left ventricular segment with good or reduced perfusion was significantly higher at six months after delayed PCI (t=13.013,10.821,both P ＜ 0.001),but the LPSS of left ventricular segment with absent perfusion was similar to that of pre-PCI.Whether at one day prior to delayed PCI or six months after delayed PCI,there were significant differences in LPSS parameters among the three groups (at one day prior to delayed PCI,myocardial perfusion absent vs reduced or good,t=4.201 and 11.771,both P ＜ 0.001;myocardial perfusion reduced vs good,t=12.561,P ＜ 0.001;at six months after delayed PCI,myocardial perfusion absent vs reduced or good,t=9.714 and 15.646,both P ＜ 0.001;myocardial perfusion reduced vs good,t=9.254,P ＜ 0.001).The LPSS both at one day prior to delayed PCI and six months after delayed PCI in myocardial perfusion good group ＞ those of myocardial perfusion reduced group ＞ those of myocardial perfusion absent group.PSI was positively correlated with GLS at both one day prior to delayed PCI and six months after delayed PCI (r=0.69,0.72,both P ＜ 0.001).MPS was positively correlated with LPSS at both one day prior to delayed PCI and six months after delayed PCI (r=0.49 and 0.45,both P ＜ 0.001).Conclusion Myocardial perfusion before delayed PCI,monitored by MCE,is correlated well with myocardial systolic function,and may be used to predict the recovery of myocardial systolic function after delayed PCI.

Independent associations between resistin and left ventricular mass and myocardial dysfunction in a community sample with prevalent obesity.

BACKGROUND: Although the adipokine resistin may play a role in heart failure, the mechanisms of this effect are uncertain. Relations with left ventricular mass (LVM) and function are uncertain. METHODS: In 739 randomly selected participants from a community sample (43.6% obese), we assessed relations between circulating resistin concentrations and LVM index (LVMI), LVM beyond that predicted by stroke work (inappropriate LVMI [LVMinappr]) and systolic and diastolic LV function (echocardiography). RESULTS: Resistin concentrations were not independently associated with blood pressure (BP). However, resistin concentrations were associated with LVMI (partial r=0.12, p<0.0005), LVMinappr (partial r=0.18, p<0.0001) and LV hypertrophy (partial r=0.13, p<0.001) independent of BP, BMI, the homeostasis model of insulin resistance and additional confounders. Independent relations between resistin concentrations and LVMI and LVMinappr persisted with further adjustments for C-reactive protein concentrations. Resistin concentration (partial r=-0.12, p<0.002 in all and partial r=-0.15, p<0.0005 in untreated) was the only factor independently associated with LV midwall fractional shortening and these relations were enhanced at incremental concentrations of CRP. Resistin was not independently associated with transmitral and myocardial tissue Doppler indices of LV diastolic function. CONCLUSIONS: Resistin in-part explains variations in LVM, hypertrophy and myocardial systolic dysfunction, and these effects are independent of insulin resistance and general inflammatory changes.

Global and regional functional assessment of ischemic heart disease with cardiac MR imaging.

Cardiac MR imaging (CMR) combines assessment of myocardial function and tissue characterization, and is therefore ideally suited to evaluating patients with ischemic heart disease (IHD). This article discusses evaluation of left ventricular global function at CMR, reviewing the literature supporting global parameters in risk stratification and assessment of treatment response in IHD. Techniques for assessment of regional myocardial function are reviewed, and normal myocardial motion and fiber arrangement discussed. Despite barriers to clinical adoption, integration of this assessment into clinical routine should improve the ability to detect functional consequences of early myocardial structural alterations in patients with IHD.

Role of ILK in the dysfunction of myocardium contraction following hemorrhagic shock / 重庆医学

Objective To explore the effect of ILK on myocardium contraction following hemorrhagic shock .Methods With iso-lated cardiac papillary muscle and isolated heart ,the contraction of papillary muscle and hemodynamic parameters (left intraventricu-lar systolic pressure(LVSP) ,the maximal change rate of left intraventricular pressure were measured .Results Compared with nor-mal control hearts ,ILK activity ,contractile response of cardiac papillary muscle and hemodynamic parameter were decreased signifi-cantly gradually in shock heart at the 1 ,2 h(P<0 .05) ,and the change of ILK activity was positive correlative with contractile re-sponse and hemodynamic parametert .With ILK agonist [phosphatidylinositol(3 ,4 ,5)trisphosphate ,PLTP] the dysfunction of con-tractile response and hemodynamic parameter could be improved significantly (P<0 .05) ,while these improvement could be abol-ished by ILK specific inhibitor(P<0 .05) .Conclusion ILK play important role in the regulation of cardiac contractility following hemorrhagic shock .

Correlation between myocardial dysfunction and perfusion impairment in diabetic rats with velocity vector imaging and myocardial contrast echocardiography.

The purpose of this study was to investigate whether myocardial systolic dysfunction and perfusion impairment occur in diabetic rats, and to assess their relationship using velocity vector imaging (VVI) and myocardial contrast echocardiography (MCE). Forty-six rats were randomly divided into either control or the diabetes mellitus (DM) groups. DM was induced by intraperitoneal administration of streptozotocin. Twelve weeks later, 39 survival rats underwent VVI and MCE in short-axis view at the middle level of the left ventricle, both at rest and after dipyridamole stress. VVI-derived contractile parameters included peak systolic velocity (Vs ), circumferential strain (εc ), strain rate (SRc ), and their reserves. MCE-derived perfusion parameters consisted of myocardial blood flow (MBF) and myocardial flow reserve (MFR). At rest, SRc in the DM group was significantly lower than in the control group, Vs , εc , and MBF did not differ significantly between groups. After dipyridamole stress, all VVI parameters and their reserves in the DM group were significantly lower than those in the control group, MBF and MFR were substantially lower than those in the control group, too. Meanwhile, significant correlations between VVI parameter reserves and MFR were observed in the DM group. Both myocardial systolic function and perfusion were impaired in DM rats. Decreased MFR could be an important contributor to the reduction in myocardial contractile reserve.