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Background: Progression to combined post‐ and pre‐capillary pulmonary hypertension (PH) provides prognostic information in human patients with post‐capillary PH. Pulmonary vascular resistance estimated by echocardiography (PVRecho) is useful for the stratification of dogs with myxomatous mitral valve disease (MMVD) and detectable tricuspid regurgitation. Objectives: To evaluate the prognostic value of PVRecho in dogs with MMVD. Animals: Fifty‐four dogs with MMVD and detectable tricuspid regurgitation. Methods: Prospective cohort study. All dogs underwent echocardiography. The PVRecho was calculated based on tricuspid regurgitation and the velocity‐time integral of the pulmonary artery flow. To evaluate the influence of echocardiographic variables on cardiac‐related deaths, Cox proportional hazard analysis was performed. Additionally, Kaplan‐Meier curves classified by PVRecho tertiles were made and compared using log‐rank tests to evaluate the influence of PVRecho on all‐cause mortality and cardiac‐related death. Results: The median follow‐up time was 579 days. Forty‐one dogs with MMVD (PH severity [number]: no or mild, 21/33; moderate, 11/11; severe, 9/10) died during the study. In the multivariable Cox proportional hazard analysis adjusted for age, sildenafil administration, and American College of Veterinary Internal Medicine stage of MMVD, left atrial to aortic diameter ratio and PVRecho remained significant (adjusted hazard ratio [95% confidence interval]: 1.2 [1.1‐1.3] and 2.1 [1.6‐3.0], respectively). Higher PVRecho showed a significant association with lower survival rates. Conclusions and Clinical Importance: Left atrial enlargement and high PVRecho were independent prognostic factors in dogs with MMVD and detectable tricuspid regurgitation. [ABSTRACT FROM AUTHOR]

An 8‐month‐old domestic short‐haired female cat presented with acute tachypnea, poor growth, hypothermia, and lethargy. Thoracic radiography showed cardiomegaly with mild pleural effusion, and transthoracic echocardiography identified dilatation of both atria and left ventricular systolic dysfunction. Although clinical signs improved temporarily with treatment, the cat died of pulmonary edema 135 days after the first visit. At necropsy, the heart was grossly enlarged. Microscopic examination of the heart identified severe vacuolization of cardiac muscle cells in histologic sections stained with hematoxylin and eosin. Examination of periodic acid‐Schiff stained preparations of formalin‐fixed heart tissue disclosed coarse granules within vacuoles that disappeared on predigestion with diastase, indicating that they were glycogen. On the basis of these findings, a necropsy diagnosis of glycogen storage disease type II (Pompe disease) was made. This report is the first case of a young cat with clinical signs closely resembling infantile Pompe disease of humans. [ABSTRACT FROM AUTHOR]

Adipose tissue-derived mesenchymal stem cells (ADSCs) have anti-inflammatory and immunomodulatory characteristics. Many studies have suggested that the immunomodulation of ADSCs is largely mediated by secreted paracrine factors. Various factors are secreted from ADSCs, among which extracellular vesicles are considered to play a major role in the communication between ADSCs and target cells. Several studies have reported the function of canine ADSC-derived extracellular vesicles (cADSC-EVs), but few studies have reported the immunomodulatory effects of cADSC-EVs on immune cells. The purpose of this study was to investigate the effects of cADSC-EVs on in vitro-stimulated CD4+ T cells isolated from peripheral blood mononuclear cells (PBMCs). cADSC-EVs were isolated from cADSCs under naive conditions or primed conditions by tumor necrosis factor-α (TNFα) and interferon-γ (IFNγ). The expression levels of several microRNAs in cADSC-EVs were altered by priming with TNFα and IFNγ. Culturing PBMCs stimulated with concanavalin A in the presence of naive or primed cADSC-EVs inhibited the differentiation of PBMCs and CD4+ T cells and promoted apoptosis of PBMCs. CD4+, CD8+, and CD4+CD8+ T cells were decreased, while CD3+CD4-CD8- T cells were increased. T helper (Th) 1, Th2, Th17, and regulatory T (Treg) cells were analyzed by flow cytometry. cADSC-EVs inhibited the proliferation of Th1 and Th17 cells and enhanced Th2 and Treg cell proliferation. However, CD4+ T cells that had incorporated labeled cADSC-EVs comprised only a few percent of all cells. Therefore, these responses of stimulated CD4+ T cells may be due to not only direct effects of cADSC-EVs but also to indirect effects through interactions between cADSC-EVs and other immune cells. In conclusion, cADSC-EVs exert immunosuppressive effects on stimulated CD4+ T cells in vitro. These findings may be useful for further studies of immune diseases. [ABSTRACT FROM AUTHOR]

Background: Tricuspid annular plane systolic excursion (TAPSE) is a common right ventricular (RV) function indicator. However, TAPSE was not decreased in dogs with myxomatous mitral valve disease (MMVD) and postcapillary pulmonary hypertension (PH) because of its load, angle, and body weight dependency, and TAPSE was considered a preload‐dependent index. Objectives: To evaluate the utility of TAPSE normalized by RV size in dogs with postcapillary PH. Animals Twenty healthy dogs and 71 MMVD dogs with or without PH. Methods: In this prospective observational study, end‐diastolic RV internal dimension (RVIDd), end‐diastolic and end‐systolic RV area, and end‐diastolic RV wall thickness were measured as RV size indices. The TAPSE was measured using B‐mode and M‐mode methods. Normalized TAPSE was calculated by dividing TAPSE by each RV size index. The RV strain was obtained as the detailed RV function using 2‐dimensional speckle tracking echocardiography. All indices were compared among the PH severity groups and in the presence of right‐sided congestive heart failure (R‐CHF). Results: Although nonnormalized TAPSE was higher with PH severity progression, each normalized TAPSE showed a significant decrease in the severe PH group (P <.05). The TAPSEB‐mode/RVIDd ratio had high area under the curve to predict R‐CHF and had moderate correlation with RV strain (P <.05). The TAPSEB‐mode/RVIDd and left atrial‐to‐aortic diameter ratios were independent predictors for R‐CHF. Conclusions and Clinical Importance: Normalized TAPSE could reflect RV systolic dysfunction in dogs with severe PH, which could not be detected by nonnormalized TAPSE. The TAPSEB‐mode/RVIDd ratio might predict R‐CHF with high sensitivity and reproducibility. [ABSTRACT FROM AUTHOR]

Background: Hypertrophic cardiomyopathy (HCM), a primary disorder of the myocardium, is the most common cardiac disease in cats. However, determination of layer‐specific myocardial function with 2D speckle‐tracking echocardiography in cats with asymptomatic HCM has not yet been reported. Objectives: To quantitatively measure layer‐specific myocardial function of asymptomatic cats with HCM. Animals Ten client‐owned, asymptomatic cats with obstructive HCM and 13 healthy cats. Methods: A retrospective, case‐control study. Cats underwent assessment of layer‐specific myocardial function (whole, endocardial, and epicardial) in the longitudinal and circumferential directions by using 2D speckle‐tracking echocardiography. Results: Longitudinal strains were significantly lower in cats with HCM than controls in the whole (−15.5% vs −19.1%), endocardial (−18.3% vs −21.8%), and epicardial (−13.1% vs −16.8%) layers. Circumferential strains in whole and epicardial layers also were significantly lower in cats with HCM as compared with controls (−15.0% vs −20.2% and − 4.4% vs −9.4%, respectively). However, no significant difference was found between cats with HCM and controls in the global circumferential strain in the endocardial layer (−31.2% vs −34.2%). The circumferential endocardial‐to‐epicardial strain ratio was significantly higher in cats with HCM than in controls (6.1 vs 3.5). Conclusions and Clinical Importance: Layer‐specific myocardial function assessed by 2D speckle‐tracking echocardiography differed in asymptomatic cats with obstructive HCM compared to controls despite their apparently normal systolic function, as determined by conventional echocardiography. The maintained endocardial circumferential strain and higher circumferential endocardial‐to‐epicardial strain ratio may reflect compensation for occult systolic dysfunction in cats with obstructive HCM. [ABSTRACT FROM AUTHOR]