Impact of repaired aortic coarctation in left ventricular myocardial work

AimsMyocardial strain analysis enables more precise assessment of cardiac performance but is relatively load dependent. New tools have been developed with afterload adjustment. Our objective was to assess myocardial work (MW) in patients with repaired aortic coarctation (rACo).MethodsProspective study of consecutive patients with rACo who underwent a routine transthoracic echocardiogram in 2018 and 2019 at our center. Patients with significant aortic valve disease, pacemaker, or other congenital heart diseases (except for mild bicuspid aortic valve disease) were excluded. Global longitudinal strain with two dimensional speckle tracking analysis and MW were obtained (GWI:Global Work Index; GCW: Global Constructive Work; GWW: Global Wasted Work; GWE: Global Work Efficiency). Blood pressure was measured in the patient's right arm.ResultsWe included 42 patients in the analysis, mean age of 37±10 years, 38% males. In this group, 52% had hypertension and 64% had a concomitant bicuspid aortic valve. In comparison to previously published reference values, patients with rACo had significantly lower GWI (1807 vs. 1896 mmHg%) and GCW (2173 vs. 2232 mmHg%) (p<0.001), particularly in males. Systolic blood pressure is an independent predictor for GWI (β=0.432) and for GCW (β=0.534) and GLS an independent predictor of all MW parameters (β>0.594). Neither age nor gender were independent predictors.ConclusionsIn patients with rACo, there are some signs of left ventricular dysfunction with a reduction in GCW and GWI and with preserved GWE, despite normal ejection fraction and strain.     

衰减伪影对冠心病患者门控心肌灌注显像图像质量及灌注结果的影响

目的探讨衰减伪影对冠心病患者门控心肌灌注显像(GMPI)图像质量及灌注结果的影响。资料与方法回顾性分析2020年3月—2021年3月在郑州大学第一附属医院核医学科经冠状动脉造影证实且于造影前后1周行GMPI的99例冠心病患者的图像,定性及半定量分析衰减校正前后GMPI图像结果,比较衰减校正前后左心室各壁段平均放射性计数及灌注结果的差异,进一步分析衰减校正前后灌注结果不一致部分的受检者的节段性室壁运动及增厚情况。结果与衰减校正前比较,衰减校正后左心室间隔、下后壁及侧壁的平均放射性计数较高(Z=-7.302、-8.014、-3.991,P均<0.001),心尖部较低(Z=-8.021,P<0.001)。其中女性衰减校正后前壁平均放射性计数减低(Z=-2.314,P=0.021)。男性衰减校正前后下后壁放射性计数差值明显高于女性(t=-8.408,P<0.05)。衰减校正后44%(44/99)的左前降支及37%(37/99)的右冠状动脉分支供血区域显像结果发生改变,结合超声心动图及GMPI结果显示其中85%(35/41)的左前降支及81%(29/36)的右冠状动脉分支供血区域室壁运动及室壁增厚率均正常。结论衰减伪影对GMPI的图像质量和灌注结果有较大影响,结合室壁运动和增厚情况等有助于鉴别衰减伪影,提高诊断准确度与特异度。     

Interrelationships between Cellular Density,Mosaic Patterning,and Dendritic Coverage of VGluT3 Amacrine Cells

Amacrine cells of the retina are conspicuously variable in their morphologies, their population demographics, and their ensuing functions. Vesicular glutamate transporter 3 (VGluT3) amacrine cells are a recently characterized type of amacrine cell exhibiting local dendritic autonomy. The present analysis has examined three features of this VGluT3 population, including their density, local distribution, and dendritic spread, to discern the extent to which these are interrelated, using male and female mice. We first demonstrate that Bax-mediated cell death transforms the mosaic of VGluT3 cells from a random distribution into a regular mosaic. We subsequently examine the relationship between cell density and mosaic regularity across recombinant inbred strains of mice, finding that, although both traits vary across the strains, they exhibit minimal covariation. Other genetic determinants must therefore contribute independently to final cell number and to mosaic order. Using a conditional KO approach, we further demonstrate that Bax acts via the bipolar cell population, rather than cell-intrinsically, to control VGluT3 cell number. Finally, we consider the relationship between the dendritic arbors of single VGluT3 cells and the distribution of their homotypic neighbors. Dendritic field area was found to be independent of Voronoi domain area, while dendritic coverage of single cells was not conserved, simply increasing with the size of the dendritic field. Bax-KO retinas exhibited a threefold increase in dendritic coverage. Each cell, however, contributed less dendrites at each depth within the plexus, intermingling their processes with those of neighboring cells to approximate a constant volumetric density, yielding a uniformity in process coverage across the population.SIGNIFICANCE STATEMENT Different types of retinal neuron spread their processes across the surface of the retina to achieve a degree of dendritic coverage that is characteristic of each type. Many of these types achieve a constant coverage by varying their dendritic field area inversely with the local density of like-type neighbors. Here we report a population of retinal amacrine cells that do not develop dendritic arbors in relation to the spatial positioning of such homotypic neighbors; rather, this cell type modulates the extent of its dendritic branching when faced with a variable number of overlapping dendritic fields to approximate a uniformity in dendritic density across the retina.     

Coronary Artery Embolism: Two Case Reports and a Review of the Literature

Coronary embolism (CE) is an uncommon and unique cause of acute myocardial infarction. In this report, we review 216 cases of CE including 2 new cases from our institution. The mean patient age was 52.5 years and 62% of the patients were males. Chest pain was the most common presenting symptom followed by dyspnea, and the most commonly affected vessel was the left anterior descending artery. Leading etiologies of the embolus were atrial fibrillation, septic emboli, and iatrogenic causes. Treatment approaches varied with thrombus aspiration being used in 30% of cases. In-hospital mortality rate was 36% and 13% of the cases were complicated by cerebrovascular accident. CE is a unique pathology that leads to acute myocardial infarction. It portends a high mortality rate and requires a high level of suspicion as symptoms may be misleading. Further research is needed in order to improve recognition and management and to lower associated mortality.     

Morphological,Functional, and Tissue Characterization of Silent Myocardial Involvement in Patients With Primary Biliary Cholangitis

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