Prognostic value of echocardiographic indices of left atrial morphology and function in dogs with myxomatous mitral valve disease

Background: The prognostic relevance of left atrial (LA) morphological and functional variables, including those derived from speckle tracking echocardiography (STE), has been little investigated in veterinary medicine. Objectives: To assess the prognostic value of several echocardiographic variables, with a focus on LA morphological and functional variables in dogs with myxomatous mitral valve disease (MMVD). Animals: One-hundred and fifteen dogs of different breeds with MMVD. Methods: Prospective cohort study. Conventional morphologic and echo-Doppler variables, LA areas and volumes, and STE-based LA strain analysis were performed in all dogs. A survival analysis was performed to test for the best echocardiographic predictors of cardiac-related death. Results: Most of the tested variables, including all LA STE-derived variables were univariate predictors of cardiac death in Cox proportional hazard analysis. Because of strong correlation between many variables, only left atrium to aorta ratio (LA/Ao > 1.7), mitral valve E wave velocity (MV E vel > 1.3 m/s), LA maximal volume (LAVmax > 3.53 mL/kg), peak atrial longitudinal strain (PALS < 30%), and contraction strain index (CSI per 1% increase) were entered in the univariate analysis, and all were predictors of cardiac death. However, only the MV E vel (hazard ratio [HR], 4.45; confidence interval [CI], 1.76-11.24; P <.001) and LAVmax (HR, 2.32; CI, 1.10-4.89; P =.024) remained statistically significant in the multivariable analysis. Conclusions and Clinical Importance: The assessment of LA dimension and function provides useful prognostic information in dogs with MMVD. Considering all the LA variables, LAVmax appears the strongest predictor of cardiac death, being superior to LA/Ao and STE-derived variables

Prevalence and prognostic role of L wave and selected clinical and echocardiographic variables in dogs with atrial fibrillation

Background: Information regarding the frequency of L waves and their prognostic relevance in dogs with secondary atrial fibrillation (AF) is limited. Hypothesis/objectives: To determine whether L waves occur and ascertain their prognostic role, as well as the role of other clinical and echocardiographic variables in dogs with AF. Animals: Fifty-five dogs with AF associated with myxomatous mitral valve disease or dilated cardiomyopathy. Methods: Retrospective, multicenter observational study. In addition to L waves analysis, other clinical and echocardiographic variables, including type of antiarrhythmic treatment, were evaluated. A survival analysis was performed to test for predictors of cardiac death and all-cause mortality using Cox proportional hazards regression models. Results: L waves were evident in 33/55 dogs (60%, 95% confidence interval [CI]&nbsp;=&nbsp;47%-72%) but their presence did not influence outcome. Increased left ventricular end-systolic diameter normalized for body weight (LVSDn) was a significant predictor of both cardiac death (hazard ratio [HR]&nbsp;=&nbsp;4.41, 95% CI&nbsp;=&nbsp;1.18-16.54; P&nbsp;=&nbsp;.03) and all-cause mortality (HR&nbsp;=&nbsp;9.39, 95% CI&nbsp;=&nbsp;2.49-35.32; P &lt; .001). Heart rate assessed during echocardiography (Echo-HR) represented an additional significant predictor of cardiac death (HR&nbsp;=&nbsp;1.01, 95% CI&nbsp;=&nbsp;1.00-1.01; P&nbsp;=&nbsp;.04) and all-cause mortality (HR&nbsp;=&nbsp;1.01, 95% CI&nbsp;=&nbsp;1.00-1.01; P&nbsp;=&nbsp;.04). Conclusions and clinical importance: L waves occurred frequently in dogs with AF, but held no prognostic relevance. Conversely, LVSDn and Echo-HR represented independent predictors of negative outcome in these animals

Echocardiographic predictors of first onset of atrial fibrillation in dogs with myxomatous mitral valve disease

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Endothelial dysfunction in patients with spontaneous venous thromboembolism

Background and Objectives A high incidence of atherosclerotic lesions and cardiovascular events has been reported in patients with spontaneous venous thromboembolism. Endothelial dysfunction is an early marker of atherosclerosis and has predictive value for ischemic events. We have evaluated endothelial function in patients with a history of spontaneous venous thromboembolism.Design and Methods Patients with a history of symptomatic, objectively confirmed, spontaneous venous thromboembolism were included in a case-control study. Exclusion criteria were any known risk factors for cardiovascular diseases, other conditions associated with endothelial dysfunction, estro-progestinic therapy or pregnancy. Controls were age-(±5 years) and sex-matched subjects with the same exclusion criteria but without previous venous thromboembolism. Endothelial function was evaluated by the non-invasive measurement of flow-mediated vasodilation of the brachial artery and of plasma markers of endothelium activation; platelet activation parameters were also measured.Results Twenty-eight cases (8 females; mean age 59±15 years) and 28 controls (8 females; mean age 58±15) were studied. Flow-mediated vasodilation was 3.5±0.6% in cases (95% CIs: 2.2 to 4.8) and 5.7±0.6% (4.2 to 6.8) in controls (p=0.015). Brachial artery blood flow and hyperemic blood flow did not differ between the two groups. Plasma von Willebrand factor and soluble P-selectin levels were significantly higher in patients with venous thromboembolism, while plasma soluble CD40 ligand and urinary 11-dehydro-TxB2 levels were similar in cases and controls.Interpretation and Conclusions Patients with spontaneous venous thromboembolism have endothelial dysfunction, unlike age- and sex- matched controls. This finding suggests that spontaneous venous thromboembolism may be a condition associated with an enhanced risk of atherosclerosis

Risk factors for atrial fibrillation in dogs with dilated cardiomyopathy

IntroductionAtrial fibrillation secondary to dilated cardiomyopathy (DCM) frequently affects large-breed dogs. The aim of the present study was to identify risk factors for the development of atrial fibrillation in dogs of different breeds with an echocardiographic diagnosis of DCM.MethodsIn this multicenter retrospective study, we searched the electronic databases of five cardiology referral centers for dogs with an echocardiographic diagnosis of DCM. A comparison of clinical and echocardiographic variables was performed between dogs developing atrial fibrillation and those not developing atrial fibrillation and the ability to distinguish between these two groups of dogs was evaluated by receiver operating characteristic curve analysis. Univariate and multivariable logistic regression analysis estimated the odds ratio (OR) with 95% confidence interval (CI) of developing atrial fibrillation.ResultsWe included 89 client-owned dogs with occult and overt echocardiographic DCM. Of these, 39 dogs (43.8%) had atrial fibrillation, 29 dogs (32.6%) maintained a sinus rhythm, and 21 dogs (23.6%) showed other cardiac arrhythmias. Left atrial diameter had high accuracy (area under the curve = 0.816, 95% CI = 0.719–0.890) to predict the development of atrial fibrillation at the cut-off of &gt;4.66 cm. After multivariable stepwise logistic regression analysis, only increased left atrial diameter (OR = 3.58, 95% CI = 1.87–6.87; p &lt; 0.001) and presence of right atrial enlargement (OR = 4.02, 95% CI = 1.35–11.97; p = 0.013) were significant predictors of atrial fibrillation development.DiscussionAtrial fibrillation is a common complication of DCM in the dog and is significantly associated with increased absolute left atrial diameter and right atrial enlargement

Io. Baptistae Guglielmini de Diurno terrae motu experimentis physico-mathematicis confirmato opusculum

Giovanni Battista Guglielmin

Kiri prof. Francesconi'le

Guglielmini, Giovanni Battista, ?-1817, itaalia matemaatikFrancesconi, Daniello, 1761-1835, filosoofiaprofessor Padua

Elementi di trasmissione del calore

Introduzione ; concetti fondamentali di conduzione termica ; conduzione termica in regime stazionario ; conduzione termica in regime variabile ; analisi numerica nei problemi do conduzione ; concetti fondamentali di convezione termica ; convezione forzata ; convezione naturale ; scambio termico in ebollizione e condensazione ; concetti fondamentali di radiazione termica ; scambio termico per radiazione ; scambiatori di calore ; problemi termici negli edifici

Atrial fibrillation in the dog

Atrial fibrillation is the most common supraventricular arrhythmia in the dog and is most frequently observed in animals with cardiac disease associated with remodelling of the left atrium. Increased body weight is a risk factor for the development of this arrhythmia, whereas sex and age do not, differently from humans. The development of atrial fibrillation is a negative prognostic factor in dogs with myxomatous mitral valve disease and dilated cardiomyopathy associated with congestive heart failure. Treatment of canine atrial fibrillation aims at reducing the heart rate, because arrhythmia is usually long-standing persistent or permanent, and restoration of a stable sinus rhythm can be difficult