Establishment of a canine model of pulmonary arterial hypertension induced by dehydromonocrotaline and ultrasonographic study of right ventricular remodeling.

OBJECTIVE: Pulmonary arterial hypertension (PAH) means high blood pressure in the lungs. We aimed to observe the right ventricular size, wall thickness and characteristic functional changes and their associations with PAH in an established model of beagle dogs, and to explore convenient, reliable and sensitive ultrasound indicators for assessing right ventricular remodeling. METHODS: Twenty healthy beagle dogs (8-10 kg) were randomly divided into control group (N-dimethylformamide, n = 10) and dehydromonocrotaline (DHMCT) group (DHMCT, n = 10). N-dimethylformamide or DHMCT was injected through a catheter into the right atrium, and then right heart catheterization, routine echocardiography and two-dimensional speckle tracking imaging (2D-STI) were performed before modeling (0 weeks) and 8, 14 weeks after modeling. Hemodynamic parameters and right ventricular function-related ultrasound data were acquired. At the end of the experiment, the animals were killed and the lung tissues were taken for HE staining. Left and right ventricular walls were separated and weighed respectively, and right ventricular hypertrophy index (RVHI) was measured. The associations of the routine ultrasound data and 2D-STI data at each time point with hemodynamic parameters and RVHI were analyzed. RESULTS: At 0, 8 and 14 weeks, gradual decreases in the right ventricular global longitudinal strain (RVLS) were found in DHMCT group. RVH occurred in DHMCT group, and DHMCT group had a significantly higher RVHI than that of control group (49.83 ± 4.83% vs. 39.80 ± 1.40%, P < .001) and larger pulmonary artery media thickness. RVLS had significant positive correlations with RVSP (r = 0.74, P < .001), mRVP (r = 0.72, P < .001), PASP (r = 0.75, P < .001), mPAP (r = 0.72, P < .001) and PVR (r = 0.68, P < .001). There was a significant positive correlation between RVLS and RVHI (r = 0.74, P < .001). CONCLUSION: The right ventricular function in PAH can be effectively assessed by echocardiography, and RVLS measured by 2D-STI sensitively reflects right ventricular remodeling following PAH.

Myocardial Work Measurement With Functional Capacity Evaluation in Primary Systemic Hypertension Patients: Comparison Between Left Ventricle With and Without Hypertrophy.

OBJECTIVE: Noninvasive measurement of myocardial work (MW) incorporates left ventricular (LV) pressure, and, therefore, allows correction of global longitudinal strain for changing afterload conditions. We sought to investigate MW as a tool to detect early signs of LV dysfunction in primary systemic hypertension patients, particularly with different predictive indices. METHODS AND RESULTS: None left ventricular hypertrophy (NLVH) and left ventricular hypertrophy (LVH) patients established were all primary systemic hypertension with preserved ejection fraction. Forty in NLVH and forty in LVH according to left ventricular end-diastolic mass index (LVEDmassI) were prospectively enrolled. The following indices of MW were assessed: global work index, global constructive work, global wasted work (GWW), and global work efficiency (GWE). Both global work index (P=0.348) and global constructive work (P=0.225) were increased in NLVH and decreased in LVH, and GWW (P<0.001) was increased significantly in NLVH and increased more in LVH, while GWE (P<0.001) was decreased significantly in NLVH and decreased more in LVH. The clinical utility of GWW (95% CI: 0.802-0.951) and GWE (95% CI: 0.811-0.950) were verified by receiver-operating characteristic curve analysis showing larger net benefits as evaluated with LVH and control comparisons. In multivariate linear regression analysis, 4-dimenaional LVEDmassI was independently associated with GWE (P=0.018) in systemic hypertension patients. Assessment of intraobserver and interobserver variability in the MW echocardiographic data documented good interclass correlation coefficients (all >0.85). CONCLUSION: GWW and GWE derived from MW are more accurate, sensitive, and reproducible predictors to detect early LV dysfunction in primary systemic hypertension patients, especially in distinguishing the potential functional abnormality of NLVH and LVH, even though the ejection fraction is preserved.

Influence of Heat Stress on Intestinal Epithelial Barrier Function, Tight Junction Protein, and Immune and Reproductive Physiology.

The potential threat of global warming in the 21st century is on the ecosystem through many aspects, including the negative impact of rising global temperature on the health of humans and animals, especially domestic animals. The damage caused by heat stress to animals has been more and more significant as the worldwide climate continues to rise, along with the breeding industry's expanding scale and stocking density, and it has become the most important stress-causing factor in southern China. In this review, we described the effects of heat stress on animal immune organs and immune system. The much-debated topic is how hyperthermia affects the tight junction barrier. Heat stress also induces inflammation in the body of animals causing low body weight and loss of appetite. This review also discussed that heat stress leads to hepatic disorder, and it also damages the intestine. The small intestine experiences ischemia, and the permeability of the intestine increases. Furthermore, the oxidative stress and mitogen-activated protein kinase (MAPK) pathways have a significant role in stress-induced cellular and organ injury. The study has shown that MAPK activity in the small intestine was increased by heat stress. Heat stress caused extreme small intestine damage, enhanced oxidative stress, and activated MAPK signaling pathways.

Epicardial adipose tissue and right ventricular function in type 2 diabetes mellitus using two-dimensional speckle tracking echocardiography.

BACKGROUND: Epicardial adipose tissue is an emerging cardiovascular risk factor. The aim of this study was to evaluate right ventricular function and investigate its association with EAT in T2DM patients. METHODS: 154 T2DM patients were divided into two groups according to EAT thickness: T2DM with EAT <5 mm and T2DM with EAT ≥5 mm. Seventy non-T2DM patients were enrolled as control group. RV function was evaluated using both conventional echocardiography as well as two-dimensional speckle tracking echocardiography. EAT thickness was measured as the echo-free space between the free wall of the right ventricle and the visceral layer of pericardium at end-systole. RESULTS: Compared to control group, EAT thickness was significantly higher and RV systolic function and early diastolic function are all impaired in all T2DM patients. In T2DM with EAT ≥5 mm group, RV systolic function and early diastolic function suffered more severe impairment when compared with T2DM with EAT <5 mm group. Multivariate linear regression analysis revealed that EAT was associated with RV systolic and early diastolic dysfunction independent of traditional cardiovascular risk factors. CONCLUSIONS: Our research suggest that in T2DM patients RV systolic function and early diastolic function are all impaired which are associated with the thickened EAT.

Exploring the relative contribution of flood regimes and climatic factors to Carex phenology in a Yangtze River-connected floodplain wetland.

Hydrological regimes can combine with climatic factors to affect plant phenology; however, few studies have attempted to quantify their complex influences on plant phenology in floodplain wetlands. We obtained phenological information on Carex vegetation through MODIS normalized difference vegetation index (NDVI) data during 2001-2020, and monthly field investigation during 2011-2020. We then explored how these data were correlated with climatic factors and flood regimes in a Yangtze River-connected floodplain wetland (Dongting Lake, China). Our results showed that warmer temperature tended to advance the start of the pre-flooding growing season (SOS1), with a relative contribution of 76.1 %. Flood rising time strongly contributed to controlling the end of the pre-flooding growing season. Flood recession time and inundation duration were dominant factors determining the start of the post-flooding growing season (SOS2). Earlier flood recession time and shortened inundation duration tended to advance the SOS2. Shortened inundation duration, earlier flood recession time, and lower solar radiation tended to advance the end of the post-flooding growing season. The phenology of Carex distributed at high-elevation areas was more affected by hydrology than that of Carex distributed at low-elevation areas. Thus, climatic factors strongly affect the phenology of Carex during the pre-flooding growing season, whereas flood regimes play a dominant role in determining the phenology in the post-flooding growing season. The different responses of Carex phenology to climatic and flooding factors may provide insights for the conservation and management of floodplain wetlands in Yangtze River because Carex are primary food source and habitat for herbivorous waterfowls.

Association between epicardial adipose tissue and left ventricular function in type 2 diabetes mellitus: Assessment using two-dimensional speckle tracking echocardiography.

BACKGROUND AND AIMS: Epicardial adipose tissue (EAT) is the visceral fat between the myocardium and the visceral pericardium. Dysfunctional EAT can cause cardiovascular diseases. The aim of this study was to investigate the association between EAT and left ventricular function in type 2 diabetes mellitus (T2DM) patients by two-dimensional speckle tracking echocardiography (2D-STE). METHODS: We prospectively enrolled 116 T2DM patients who were divided into two groups according to their left ventricular global longitudinal strain (GLS): 53 with GLS <18% and 63 with GLS ≥18%. The thickness of EAT was measured as the echo-free space between the free wall of the right ventricle and the visceral layer of pericardium at end-systole. LV systolic function was evaluated by GLS measured by 2D-STE. LV diastolic function was defined as the ratio of the early diastolic transmitral flow velocity (E) to average mitral annular velocity (e¯). RESULTS: Compared with patients with GLS ≥18% group, the age, body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure (DBP), low-density lipoprotein cholesterol (LDL-C), glycosylated hemoglobinA1c (HbA1c), E/e¯, and thickness of EAT were higher in patients with GLS <18% group (all P < 0.05). Multivariate linear regression analysis revealed that the thickness of EAT was independently associated with left ventricular GLS and E/e¯. CONCLUSIONS: Thickened EAT is associated with impaired left ventricular function in T2DM patients. To investigate the association between EAT and left ventricular function can help us gain a deeper understanding of the pathogenesis of impaired cardiac function in T2DM patients.

Quantitative Differentiation of Left Atrial Performance in Hypertrophic Cardiomyopathy: Comparison Between Nonobstruction and Occult Obstruction With 4-dimensional Volume-strain.

OBJECTIVE: The objective of this study was to describe the different components of left atrial (LA) dysfunction predictors in nonobstructive and occult obstructive hypertrophy cardiomyopathy (HCM) patients especially with preserved left ventricular (LV) ejection fraction, particularly using LA 4-dimensional (D) longitudinal and circumferential strains. METHODS: Twenty-eight nonobstructive HCM patients and 30 occult obstructive HCM patients according to LV outflow tract gradient at rest and after exercise were prospectively enrolled. 4D echocardiographic evaluation was performed in 58 HCM patients, both nonobstructive and occult obstructive, and 38 control subjects. LA reservoir, conduit, contractile functions were performed by 4D volume-strain with volumes and longitudinal, circumferential strains. RESULTS: Optimal correlation coefficients obtained between LV 4D mass (index) and LA 4D longitudinal/circumferential strain (r=-0.860 to 0.518, all P<0.001). Both nonobstructive and occult obstructive HCM patients had increased volumes and significantly decreased longitudinal, circumferential strain values with lower reservoir, conduit, contractile functions than the controls (all P<0.001). Occult obstructive HCM patients presented incremented volumes compared with nonobstructive ones (P<0.001 to 0.003). Lower conduit function and higher contractile function indicated with lower reservoir function revealed by circumferential strain in occult obstructive HCM patients than nonobstructive ones (P<0.001 to 0.017). Interclass correlation coefficients of intraobserver and interobserver in the LV and LA 4D value evaluations were >0.75 and >0.85, respectively. CONCLUSIONS: LA volumes were significantly increased and LA reservoir, conduit, and contractile functions were significantly impaired in HCM patients. Furthermore, different performances of LA functional analyses in nonobstruction and occult obstruction patients with 4D volume-strain echocardiography may facilitate the recognition of subtle LA dysfunctional differentiation in HCM patients.

Heart transplantation ten-year follow-ups: Deformation differentiation comparison of myocardial performance in left ventricle and right ventricle.

BACKGROUND: We try to investigate whether the values of three-dimensional principal longitudinal strain present differently between the left and right ventricles in patients with long-time follow-ups after heart transplantation (HTx). METHODS AND RESULTS: Transthoracic echocardiography with three-dimensional speckle tracking was performed at one-, five- and ten-year follow-ups in 62 "healthy" HTx patients together with routine echocardiographic evaluation in 32 control group (CG) individuals. Longitudinal strain was applied in all subjects assessing without myocardium wall motion abnormality. Firstly, left ventricular ejection fraction preserved in HTx and had no significant difference in comparison with the controls (p > .05). 3D measurement showed obvious reduction in global (%: CG: -20.5 ± 3.5 vs. HT1y: -13.7 ± 4.6, HT5y: -14.4 ± 4.5, HT10y: -14.6 ± 4.7. p < .01) and horizontal segmental (basal, mid, apical, CG vs. HTx: all p < .01) strain values of the left compared HTx with control subjects. Secondly, tissue Doppler imaging s' velocity and tricuspid annular plane systolic excursion reduced in HTx as compared to the controls in right ventricle (p < .01). Longitudinal strain presented a more distinctive reduction in global (%: CG: -24.5 ± 4.6 vs. HT1y:-14.8 ± 7.5, HT5y: -15.5 ± 6.4, HT10y: -15.9 ± 6.8. p < .01) and horizontal segmental (basal, mid, apical, CG vs. HTx: all p < .01) average values of the right compared HTx with control subjects. Thirdly, there weren't any significant changes between one-, five- and ten-year of all the values with HTx inter-group comparison in both the left and right ventricles (p > .05). Fourthly, the global and segmental strain of the right ventricle decreased more than that of the left ventricle in all HTx groups, with the global decreased differentiation rates of 7%, 7%, 6%, respectively. CONCLUSIONS: Compared HTx with control subjects in both ventricles, conventional evaluation showed preserved or decreased functions in the left and right separately. Myocardial function evaluating by 3D longitudinal strain reduced after HTx, but the deformation of the right ventricle reduced more than those of the left ventricle. Additionally, 3D strain values almost remained with stable decreased differentiation rates during the long-time follow-ups.

Four-Dimensional Volume-Strain Expression in Asymptomatic Primary Hypertension Patients Presenting with Subclinical Left Atrium-Ventricle Dysfunction.

OBJECTIVE: The purpose of this study was to evaluate the different components of left atrial (LA) dysfunction predictors in asymptomatic primary systemic hypertension patients with preserved left ventricular (LV) ejection fraction, particularly using LA 4-dimensional (4D) longitudinal and circumferential strain values. METHODS AND RESULTS: Patients with no left ventricular hypertrophy (NLVH) and left ventricular hypertrophy (LVH) are all asymptomatic regarding primary blood hypertension. Thirty NLVH patients and 30 LVH patients according to LV mass index and 40 controls analyzed by 4D echocardiography were prospectively enrolled. LA volumes and longitudinal and circumferential strains were measured using 4D volume-strain echocardiography with a Vivid E95 Version 203 instrument. Correlation analysis indicated a significant relation between LV 4D mass index and LA 4D longitudinal/circumferential strain (r = -0.446 to 0.381, p = 0.000-0.042). LVH patients had a reduced LA emptying fraction compared with NLVH patients and control subjects (p < 0.01). NLVH patients had an impaired LA conduit function and increased contractile function compared with the control group (p < 0.01). LVH patients had increased LA volumes and significantly decreased reservoir, conduit and contractile functions compared with the controls (p < 0.01). LVH patients had increased LA volumes and decreased reservoir and contractile functions compared with NLVH patients (p < 0.01). The clinical utility of LA 4D volume-strain measurement was verified by receiver-operating characteristic curve analysis showing larger net benefits as evaluated with NLVH, LVH and control group comparisons. Interclass correlation coefficients of interobserver and intraobserver assessments in the LV and LA 4D value evaluations were >0.75 and >0.85, respectively. CONCLUSIONS: LVH patients showed increased LA volumes and decreased LA emptying fractions. LA reservoir, conduit and contractile functions were significantly impaired in LVH patients. Decreased LA conduit function and increased contractile function were revealed in NLVH patients. LA volumetric and functional analyses with 4D volume-strain echocardiography may facilitate the recognition of subtle LA and LV dysfunctions in asymptomatic systemic hypertension patients.

Left and right ventricular function detection and myocardial deformation analysis in heart transplant patients with long-time follow-ups.

OBJECTIVE: We try to investigate whether the values of longitudinal strain present differences between the left and right ventricles in long-time follow-ups after heart transplantation (HTx) with dynamic changes in function. METHODS AND RESULTS: Follow-up transthoracic echocardiography was performed in 1- and 3-month and 1- and 5-year follow-ups in 50 "healthy" HTx patients and compared with 26 control subjects. The left ventricle with preserved ejection fraction evaluated by biplane Simpson (control group [CG] vs HT; P > .05) had an obvious reduction in global (CG: -20.49 ± 2.38 vs heart transplant 1 month [HT1m]: -13.06 ± 2.86, heart transplant 3 month [HT3m]: -13.61 ± 2.61, heart transplant 1 year [HT1y]: -13.69 ± 4.56, heart transplant 5 year [HT5y]: -14.41 ± 4.54; P < .001) and horizontal segmental (basal, mid, apical) (P < .001) together with chamber segmental (apical 4-chamber, apical 3-chamber, apical 2-chamber) (P < .001) average strain values. The right ventricle with reduced ventricular function measured by tissue Doppler imaging S' and tricuspid annular plane systolic excursion had a more distinctive reduction in global (CG: -24.53 ± 4.20 vs HT1m: -12.94 ± 5.03, HT3m: -13.68 ± 4.35, HT1y: -14.95 ± 7.50, HT5y: -15.20 ± 6.15; P < .001) with segmental lateral (P < .001) strain values. There were not any significant changes between 1- and 3-month follow-ups of all the values (P > .05). But it could be seen that values increased in 1- and 5-year follow-ups compared with the baseline of 1- and 3-month follow-ups (P < .05). The global and segmental strain of the right ventricle decreased more than that of the left ventricle in all HTx groups, and the strain values were decreased in the HTx groups compared with the CG, with the global decreased change rates being 11%, 10%, 6%, and 8%, respectively. CONCLUSIONS: The strain values decreased after HTx and almost remained stable in the long-time follow-ups. Compared with the CG in both ventricles, they were with preserved or reduced functions. In addition, the deformation values of the right ventricle decreased more than those of the left.

Age-related severity and distribution of haemophilic arthropathy of the knee, ankle and elbow among Chinese patients with haemophilia.

INTRODUCTION AND AIMS: Age-related severity and distribution of haemophilic arthropathy (HA) among Chinese patients with haemophilia using the Haemophilia Early Detection with Ultrasound (HEAD-US) system have not been extensively studied. METHODS: In our study, 89 patients with moderate and severe haemophilia were recruited. A total of 534 joints (knees, ankles and elbows on both sides included) were evaluated using musculoskeletal ultrasound (MSKUS) and scored using the HEAD-US system. RESULTS: Prevalence and average number of HA were 39.1% and 0.7, 90.6% and 3.2, 94.1% and 4.5, and 100% and 4.3 for ages ≤10, 11-20, 21-30 and 31-40 years, respectively. Prevalence and mean number of knee, ankle and elbow arthropathies also increased with age, although joint damages progressed in unparallel patterns. A significant difference in synovium subscores was observed between patients aged <10 and >10 years. An increasing tendency was observed in cartilage and subchondral bone subscores along with age before 30 years. No significant difference in mean joint scores was found between patients receiving on-demand therapy and those receiving on-demand to low-dose prophylactic therapy. CONCLUSIONS: Haemophilic arthropathy developed in early childhood and progressed mainly before 30 years of age among Chinese patients with haemophilia, although in different ways among the knee, ankle and elbow.

Crucial sites and environmental variables for wintering migratory waterbird population distributions in the natural wetlands in East Dongting Lake, China.

Dongting Lake is the second largest freshwater lake in China and is one of the globally important wintering sites for migratory waterbirds in the East Asian-Australasian Flyway. Crucial sites and environmental variables for wintering migratory waterbirds are of great concern in the Dongting Lake wetlands. In this research, based on annual (2003/2004-2016/2017) waterbird and habitat census data, we recognized the crucial sites for waterbirds during wintering seasons by comparing the difference of waterbird populations at the community, foraging guild and species levels in different natural wetlands within East Dongting Lake, and then identified the crucial environmental variables affecting waterbird distributions by analyzing the relationship between waterbird populations and the environmental variables, including vegetation area, mudflat area, water area with the depth of 0-20 cm, water area with the depth of 20-50 cm, water area with the depth of 50-100 cm, water area with the depth >100 cm, growth status of vegetation (Min, Mean and Max NDVI), and the human disturbance. Results indicated that five natural wetlands, i.e., Daxiaoxi, Chunfeng, Baihu lakes, Dingzi dyke and Tanjiaweizi, were recognized as the crucial wintering sites for migratory waterbirds in the East Dongting Lake. Among the ten selected environmental variables, water areas with the depth of 0-20 cm, 20-50 cm and >100 cm, human disturbance, Min and Mean NDVIs were identified as the crucial environmental variables overall. Waterbirds at different levels exhibited significant linear relationship with certain environmental variables, with the exception of Bean goose and Lesser White-fronted goose at the species level, which showed Gaussian distribution with changes in mean NDVI. The crucial environmental variables appeared to be foraging guild- and species-specific. These findings provide significant information for managers to understand the differences of wetlands and waterbird populations within East Dongting Lake, and to make more targeted conservation efforts.

Impacts of microhabitat changes on wintering waterbird populations.

Caisang Lake, a human-modified wetland, experienced dramatic habitat alterations from the planting of lotus and culturing of crab. Whether the Caisang Lake still maintains populations of wintering waterbirds is of great concern. Here, we compare the changes in waterbird populations before and after habitat alterations in Caisang Lake and assess the driving factors leading to the dramatic changes in waterbird populations. Results indicate that wintering waterbird populations were significantly impacted by altered forage availability, with species- and guild-specific responses. Dramatic habitat alterations from planting lotus caused significant declines in areas of native vegetation, mudflats, and water that may have caused associated declines in herbivores, insectivores, and fish-eating waterbirds, respectively. In contrast, the increased size of the lotus area appears to have led to an increase in omnivorous waterbirds. A food shortage, potentially caused by a large area of Caisang Lake being used for culturing crab, might be another cause of the observed decline in fish-eating waterbirds. This study demonstrates a powerful approach to systematically evaluate waterbird responses to wetland management policies. These findings are important as efforts are made to protect the wintering waterbirds from the effects of human intervention, particularly at other Ramsar wetlands.

Evaluation of left ventricular myocardial mechanics by three-dimensional speckle tracking echocardiography in the patients with different graded coronary artery stenosis.

To investigate the relationship between left ventricular (LV) myocardial mechanics evaluated by three-dimensional speckle tracking echocardiography (3D-STE) and degree of coronary artery stenosis in patients with coronary artery disease (CAD). Ninety-seven suspected CAD patients without LV regional wall motion abnormality (RWMA) observed visually form traditional echocardiography were divided into four groups according to coronary artery angiography (CAG): 23 patients in slight stenosis group [stenosis rate (SR) ≤25%], 26 patients in mild stenosis group (25< SR ≤50%), 28 patients in moderate stenosis group (50< SR ≤75%), and 20 patients in severe stenosis group (SR >75%). Global longitudinal strain (GLS), circumferential strain (GCS), radial strain (GRS), area strain (AS) and three dimensional strain (3D-Strain) were obtained. The parameters from 3D-STE were compared between different groups and then the diagnostic value of global strains indicating different graded coronary artery stenosis was analyzed by the receiver operating characteristic curve. (1) There were significant difference in GLS, GCS, GRS, GAS and 3D-Strain between the severe stenosis group and any other group while all 3D-STE parameters except GCS in the moderate stenosis group were remarkably different from those respectively in mild group. (2) Receiver operator characteristic curve (ROC) analysis showed that the area under the curve of GLS, GRS, GCS, GAS, 3D-Strain were 0.899, 0.873, 0.723, 0.856 and 0.863 respectively for the identification of stenosis rate >50%, and 0.896, 0.866, 0.797, 0.909 and 0.899 respectively for the identification of severe stenosis. GAS less than -29.13% allowed a sensitivity of 95% and a specificity of 71.4%, while 3D strain less than 41.35% allowed a sensitivity of 90% and a specificity of 80.5% for evaluating serve coronary artery stenosis. The myocardial mechanics from 3D-STE in the CAD patients were characteristic. It could be expected to identify serve coronary stenosis with a good sensitivity and an acceptable specificity by using GAS or 3D-strain especially in the suspected CAD patients without RWMA on conventional echocardiography.

Assessment of Left Ventricular Myocardial Viability by 3-Dimensional Speckle-Tracking Echocardiography in Patients With Myocardial Infarction.

OBJECTIVES: To determine whether 3-dimensional (3D) speckle-tracking echocardiography could provide a new way to assess myocardial viability in patients with myocardial infarction (MI). METHODS: Forty-five patients with MI underwent routine echocardiography, 2-dimensional (2D) speckle-tracking echocardiography, and 3D speckle-tracking echocardiography. Radionuclide myocardial perfusion/metabolic imaging was used as a reference standard to define viable and nonviable myocardia. RESULTS: Among 720 myocardial segments in 45 patients, 368 showed abnormal motion on routine echocardiography; 204 of 368 were categorized as viable on single-photon emission computed tomography/positron emission tomography (SPECT/PET), whereas 164 were defined as nonviable; 300 normal segments on SPECT/PET among 352 segments without abnormal motion on routine echocardiography were categorized as a control group. The radial, longitudinal, 3D, and area strain on 3D speckle-tracking echocardiography had significant differences between control and nonviable groups (P < .001), whereas none of the parameters had significant differences between control and viable groups. There were no significant differences in circumferential, radial, and longitudinal peak systolic strain from 2D speckle-tracking echocardiography between viable and nonviable groups. Although there was no significant difference in circumferential strain between the groups, radial and longitudinal strain from 3D speckle-tracking echocardiography decreased significantly in the nonviable group. Moreover, 3D and area strain values were lower in the nonviable segments than the viable segments. By receiver operating characteristic analysis, radial strain from 3D speckle-tracking echocardiography with a cutoff of 11.1% had sensitivity of 95.1% and specificity of 53.4% for viable segments; longitudinal strain with a cutoff of 14.3% had sensitivity of 65.2% and specificity of 65.7%; 3D strain with a cutoff of 17.4% had sensitivity of 70.6% and specificity of 77.2%; and area strain with a cutoff of 23.2% had sensitivity of 91.5% and specificity of 82.8%. CONCLUSIONS: Three-dimensional speckle-tracking echocardiography might have potential for detection of myocardial viability in patients with cardiac dysfunction due to MI.

[Viable myocardium evaluation by two dimensional speckle tracking imaging combined with adenosine stress echocardiography].

OBJECTIVE: Regional left ventricular (LV) function could be detected by measuring peak-systolic strain by speckle tracking imaging (STI). We evaluated the value of STI combined with adenosine stress echocardiography on assessing myocardial viability in patients with myocardial infarction (MI). METHODS: Two dimensional echocardiography was performed at rest and after adenosine stress echocardiography (infused at 140 µg×kg(-1)×min(-1) over a period of 6 min) in 39 stable patients with previous MI. Peak-systolic (Speak-sys) circumferential strain, radial strain and longitudinal strain were assessed by STI. Radionuclide myocardial perfusion/metabolic imaging served as the "gold standard" to detection of myocardial viability. RESULTS: (1) There were 215 viable and 153 non-viable regions among 368 abnormal motion segments out of 624 segments in 39 MI patients according to radionuclide imaging results. (2) Speak-sys was similar between viable and nonviable myocardium at rest (all P > 0.05). After adenosine infusion, radial Speak-sys [(37.98 ± 5.45)% vs. (30.22 ± 5.47)%], longitudinal Speak-sys [(-23.71 ± 4.53)% vs. (-17.52 ± 4.34)%] increased significantly (P < 0.05)in viable segments compared to baseline levels and were significantly higher than in nonviable segments radial Speak-sys [(37.98 ± 5.45)% vs. (30.12 ± 5.37)%] and longitudinal Speak-sys [(-23.71 ± 4.53)% vs. (-16.95 ± 4.62)%] (P < 0.05), while remained unchanged in nonviable segments before and after adenosine infusion. Circumferential Speak-sys was similar before and after adenosine infusion in both viable and nonviable segments (all P > 0.05). (3) Delta radial strain change > 9.8% has a sensitivity of 82.3% and a specificity of 81.1% whereas a delta change of longitudinal strain > 16.5% has a sensitivity of 83.5% and a specificity of 92.3% for detecting viable segments. CONCLUSIONS: Speckle tracking imaging combined with adenosine stress echocardiography could serve as a new and reliable method of assessing myocardial viability.

Clinic value of two-dimensional speckle tracking combined with adenosine stress echocardiography for assessment of myocardial viability.

BACKGROUND: To evaluate whether myocardial strain under adenosine stress calculated from two-dimensional echocardiography by automatic frame-by-frame tracking of natural acoustic markers enables objective description of myocardial viability in clinic. METHODS AND RESULTS: Two-dimensional echocardiography and two-dimensional speckle tracking imaging (2D STI) at rest were performed first and once again after adenosine was infused at 140 ug/kg/min over a period of 6 minutes in 36 stable patients with previous myocardial infarction. Then radionuclide myocardial perfusion/metabolic imaging served as the "gold standard" to define myocardial viability was given in all patients within 1 day. Two-dimensional speckle tracking images were acquired at rest and after adenosine administration. An automatic frame-by-frame tracking system of natural acoustic echocardiographic markers was used to calculate 2D strain variables including peak-systolic circumferential strain (CS(peak-sys)), radial strain (RS(peak-sys)), and longitudinal strain (LS(peak-sys)). Those segments with abnormal motion from visual assessment of two-dimensional echocardiography were selected for further study. As a result, 126 regions were viable whereas 194 were nonviable among 320 abnormal motion segments in 36 patients according to radionuclide imaging. At rest, there were no significant changes of 2D strain between the viable and nonviable myocardium. After adenosine administration (140 ug/kg/min), CS(peak-sys) had a little change of the viable myocardium while RS(peak-sys) and LS(peak-sys) increased significantly compared with those at rest. In nonviable group, CS(peak-sys), RS(peak-sys), and LS(peak-sys) had no significant changes during adenosine administration. After adenosine administration, RS(peak-sys) and LS(peak-sys) in viable group increased significantly compared with nonviable group. Obtained strain data were highly reproducible and affected in small intraobserver and interobserver variabilities. A change of radial strain more than 9.5% has a sensitivity of 83.9% and a specificity of 81.4% for viable whereas a change of longitudinal strain more than 14.6% allowed a sensitivity of 86.7% and a specificity of 90.2%. CONCLUSIONS: 2D STI combined with adenosine stress echocardiography could provide a new and reliable method to identify myocardium viability.

Two-dimensional strain combined with adenosine stress echocardiography assessment of viable myocardium.

The objective of this study was to explore a new method for the identification of viable myocardium by means of two-dimensional (2D) strain imaging combined with adenosine stress echocardiography. A total of 15 anesthetized open-chest healthy mongrel dogs underwent left anterior descending coronary artery occlusion for 90 min followed by 120-min reperfusion. Adenosine was infused at 140 µg kg(-1) min(-1) over a period of 6 min. Images were acquired at baseline (when pericardial cradle was made), after reperfusion (when reperfusion finished) and after adenosine administration (while administration stopped). Measurements of the regional peak-systolic strain in radial, circumferential, and longitudinal motion on anterior wall and anterior septum were, respectively, performed under different conditions. The dogs were killed after the echocardiographic studies finished and then the area of infracted myocardium was defined by triphenyltetrazolium chloride histology. A segment with equal or less than 50% area of infracted myocardium was considered to be viable. As a result, 37 regions were viable whereas 53 were non-viable among 90 regions in 15 dogs. At baseline, there was no significant difference in peak-systolic radial strain (Rs), circumferential strain (Cs), and longitudinal strain (Ls) between the viable and non-viable groups. After reperfusion, Rs, Cs, and Ls in absolute value decreased compared to those at baseline in both groups, although there was no significant difference between these groups. Rs and Ls increased after adenosine administration compared to reperfusion (p < 0.01; p < 0.05) in viable group while there were no changes in non-viable group. Compared with non-viable group Rs, Cs and Ls in viable group increased significantly (p < 0.01; 0.05) after adenosine administration. There was a negative correlation between Rs and infarct size (r = -0.72). Cs and Ls correlated well with infarct size, respectively (r = 0.40; 0.67). A change of Rs more than 13.5% has a sensitivity of 83.8% and a specificity of 83.0% for viable whereas a change of Ls more than 11% allowed a sensitivity of 78.4% and a specificity of 88.7%. Combined with these two variables, the sensitivity and specificity could reach 91.9 and 79.2%. Two-dimensional strain imaging combined with adenosine stress echocardiography can provide a new way to distinguish viable myocardium from the non-viable.