Doppler Ultrasonographic Assessment of Abdominal Aortic Flow to Evaluate the Hemodynamic Relevance of Left-to-Right Shunting Patent Ductus Arteriosus in Dogs

In this multicenter, prospective, observational study, abdominal aortic flow was examined with pulsed-wave Doppler ultrasound in dogs with a left-to-right shunting patent ductus arteriosus (PDA) and in apparently healthy dogs. Forty-eight dogs with a PDA and 35 controls were included. In the dogs with a PDA, 37/48 had hemodynamically significant PDAs (hsPDAs) while 11/48 had non-hsPDAs, based on the presence or absence of echocardiographic signs of left-sided volume overload, respectively. In 12 dogs (4/35 control dogs, 7/37 dogs with an hsPDA and 1/11 dogs with a non-hsPDA), the diastole was too short to visualize the end-diastolic flow. Antegrade end-diastolic flow was observed in 30/35 controls and 6/11 dogs with a non-hsPDA. Absent end-diastolic flow was observed in 1/35 control dogs and 3/11 dogs with a non-hsPDA. Retrograde end-diastolic flow was observed in 30/37 dogs with an hsPDA and 1/11 dogs with a non-hsPDA. Twenty-one dogs (15 with an hsPDA and 6 with a non-hsPDA) were reassessed after PDA closure, and, in 19/21, end-diastolic flow was visualized: 17/19 showed an antegrade flow, 1/19 an absent flow and 1/19 a retrograde flow. Sensitivity and specificity of retrograde end-diastolic flow for detection of hsPDAs were 100% and 90%, respectively. In conclusion, ultrasonographic assessment of abdominal aortic flow was feasible in dogs with PDA. However, end-diastolic flow was not always visualized. The presence of a retrograde end-diastolic flow was an accurate finding for discriminating hsPDAs and non-hsPDAs.

Atipamezole Reverses Cardiovascular Changes Induced by High-Dose Medetomidine in Cats Undergoing Sedation for Semen Collection

This study aimed at describing the change in echocardiographic variables after high-dose medetomidine and the reversal with atipamezole in six cats undergoing sedation for semen collection. Further cardiac Troponin I (cTnI) concentration and the effect of repeated sedation were assessed. Echocardiography was performed before and 20 min after sedation with 0.1 mg/kg medetomidine intramuscularly (IM) for urethral catheterisation. Prior to epididymectomy, S-ketamine was administered intravenously. Twenty minutes after reversal with 0.5 mg/kg atipamezole IM, the third echocardiography was performed. Sedation with medetomidine and reversal with atipamezole was repeated on day 7, 14, 21 and 28. Heart rate (HR) and rhythm were monitored throughout all sedations. On day 0 and 28 cTnI concentrations were measured before and after the procedure. After normality testing, the values were compared over time. The administration of medetomidine led to a marked reduction in HR, cardiac output and ventricular systolic function and a significant increase in left ventricular dimensions. Rhythm abnormalities, such as ventricular premature complexes and idioventricular rhythm, could be observed. The administration of atipamezole completely reversed sedation and the changes in haemodynamic variables. No significant increase in cTnI concentrations could be detected, although two out of six cats showed values above the reference range.

Risk factors for atrial fibrillation in dogs with dilated cardiomyopathy

Introduction

Atrial 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.

Methods

In 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.

Results

We 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 >4.66 cm. After multivariable stepwise logistic regression analysis, only increased left atrial diameter (OR = 3.58, 95% CI = 1.87-6.87; p < 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.

Discussion

Atrial fibrillation is a common complication of DCM in the dog and is significantly associated with increased absolute left atrial diameter and right atrial enlargement.

Radiographic features of cardiogenic pulmonary oedema in cats with left-sided cardiac disease: 71 cases

OBJECTIVES

The aims of this study were to describe the radiographic features of cardiogenic pulmonary oedema (CPE) in a large group of cats with left-sided cardiac disease, and to determine the association between the radiographic features of CPE and the underlying cardiac disease.

METHODS

Thoracic radiographs of cats with CPE and echocardiographic evidence of left-sided cardiac disease and left atrial enlargement (LAE) were reviewed, and cardiac silhouette, pulmonary vessels and pulmonary parenchyma evaluation were performed. Interstitial and/or alveolar patterns were classified according to their distribution (ie, diffuse, multifocal or focal) and location (ie, craniodorsal, cranioventral, caudodorsal, caudoventral and perihilar). A Student's t-test and Mann-Whitney U-test, or the two-proportion z-test, were used to compare continuous or categorical variables, respectively, between cats affected by the two most represented cardiac diseases, namely hypertrophic cardiomyopathy (HCM) and restrictive cardiomyopathy (RCM).

RESULTS

Seventy-one cats were included; among them, 46 (64.7%) and 13 (18.3%) had presented for HCM and RCM, respectively. Subjective and objective cardiomegaly, and subjective and objective LAE were detected in 97.2% and 91.9% of cats and in 80.3% and 40.6% of cats, respectively. Pulmonary artery abnormalities, in particular caudal pulmonary artery dilation, were found in 77.5% of cats. Pulmonary artery to pulmonary vein ratio = 1 was found in 71.8% and 55% cats on right lateral and ventrodorsal or dorsoventral views, respectively. Interstitial (57.8%) and mixed interstitial-alveolar (38%) pattern, multifocal (84.5%) and symmetrical (75%) distribution with prevalent ventrocaudal (65.6% of cats) and ventrocranial (60.9% of cats) locations were most frequently observed. No difference was found for any of these radiographic features between cats with HCM and RCM.

CONCLUSIONS AND RELEVANCE

Moderate-to-severe cardiomegaly and LAE, caudal pulmonary artery and vein dilation, as well as a ventral, multifocal and symmetrical interstitial pulmonary pattern, were the main radiographic features of CPE in evaluated cats. Underlying cardiac disease did not influence the aforementioned radiographic features.

Retrospective evaluation of hypertrophic cardiomyopathy in 68 dogs

BACKGROUND

There is a lack of clinical data on hypertrophic cardiomyopathy (HCM) in dogs.

HYPOTHESIS/OBJECTIVES

To investigate signalment, clinical signs, diagnostic findings, and survival in dogs with HCM.

ANIMALS

Sixty-eight client-owned dogs.

METHODS

Retrospective multicenter study. Medical records were searched between 2003 and 2015. The diagnosis of left ventricular (LV) hypertrophy was made by echocardiographic examination.

RESULTS

Three hundred and forty-five dogs with LV hypertrophy were identified, of which 277 were excluded. The remaining 68 dogs were 0.3 to 14 years old and predominantly <10 kg (85%), and without a sex predilection. Twenty-four % were Shih Tzu and 24% terrier breeds. Most (80%) had a systolic heart murmur. Owner-determined exercise intolerance (37%) and syncope (18%) were most commonly reported signs. The majority (84%) of dogs had symmetrical LV hypertrophy, whereas asymmetrical septal and LV free wall hypertrophy was observed in 9% and 6% of dogs, respectively. Isolated basal interventricular septal hypertrophy was not observed. Commonly recorded were systolic anterior motion of the mitral valve (60%) and LV diastolic dysfunction (89% of dogs where diastolic function was evaluated). Six dogs died unexpectedly, and 3 developed congestive heart failure. Known survival times were between 1 day and 114 months after diagnosis.

CONCLUSIONS AND CLINICAL IMPORTANCE

Hypertrophic cardiomyopathy in dogs should be considered as a differential diagnosis if LV hypertrophy is identified. Small breed dogs are overrepresented, and it is uncommon for dogs with HCM to develop CHF although sudden death can occur.

Plasmatic Dimethylarginines in Dogs With Myxomatous Mitral Valve Disease

Plasmatic dimethylarginines, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) are considered biomarkers of endothelial and renal dysfunction, respectively, in humans. We hypothesize that plasmatic concentration of dimethylarginines in dogs with myxomatous mitral valve disease (MMVD) is influenced by heart disease stage. Eighty-five client-owned dogs with MMVD, including 39, 19, and 27 dogs in ACVIM stages B1, B2, and C+D, respectively, and a control group of 11 clinically healthy dogs were enrolled. A prospective, multicentric, case-control study was performed. Each dog underwent a complete clinical examination, arterial blood pressure measurement, thoracic radiography, six-lead standard electrocardiogram, transthoracic echocardiography, CBC, biochemical profile, and urinalysis. Plasmatic concentration of dimethylarginines was determined through high-performance liquid chromatography coupled with tandem mass spectrometry. Median ADMA was significantly increased in dogs of group C+D (2.5 μmol/L [2.1–3.0]) compared to those of group B1 (1.8 μmol/L [1.6–2.3]; p < 0.001) and healthy dogs (1.9 μmol/L [1.7–2.3]; p = 0.02). Median SDMA was significantly increased in dogs of group C+D (0.7 μmol/L [0.5–0.9]) compared to those of groups B1 (0.4 μmol/L [0.3–0.5]; p < 0.001), B2 (0.4 μmol/L [0.3–0.6]; p < 0.01), and the control group (0.4 μmol/L [0.35–0.45]; p = 0.001). In the final multivariable analysis, ADMA and SDMA were significantly associated with left atrium to aorta ratio (p < 0.001), and creatinine (p < 0.001), respectively. Increased plasmatic concentrations of dimethylarginines suggest a possible role as biomarkers of disease severity in dogs with decompensated MMVD.

Radiographic and anatomical morphometric assessments of heart size in presumed healthy pet guinea pigs

Cardiac disease in guinea pigs has been reported in the literature; however, reference intervals for normal radiographic heart size obtained using objective measurement methods have not been provided for this species. The aim of this prospective, reference interval study was to describe cardiac dimensions in presumed healthy guinea pigs using the vertebral heart scale (VHS) from thoracic radiographs, as described for dogs and cats. Furthermore, an anatomical study was carried out to compare the radiographic and anatomical findings. Thoracic radiographs were acquired in right lateral recumbency for 30, client‐owned, conscious, presumed healthy guinea pigs and radiographs were acquired in left lateral recumbency for 10 presumed healthy guinea pigs as comparisons. The influence of sex, age, body weight (BW), and recumbency on the VHS and absolute cardiac measurements was investigated. The median (interquartile range; IQR) VHS was 7.4 (7.1‐7.6). No differences emerged between the VHS measured in right versus left lateral recumbency (P = .41) or between sexes (P = .16). The VHS values were not influenced by age (P = .53) or BW (P = .26). The anatomical study was carried out on 10 guinea pig cadavers, and in situ and ex situ cardiac measurements were taken using a caliper. A median (IQR) 7.5 (7.2‐8.0) VHS was assessed by this anatomical study. The reference intervals provided should be useful tools in the future for the radiographic interpretation of cardiac size in guinea pigs in clinical practice.

Contrast-enhanced ultrasonography in dogs with inflammatory bowel disease

Background

Contrast‐enhanced ultrasonography (CEUS) is used to evaluate vascularity of the gastrointestinal wall in neoplastic and inflammatory diseases.

Objective

To assess the feasibility of CEUS for the evaluation of duodenal perfusion in dogs with inflammatory bowel disease (IBD).

Animals

Forty‐two dogs with IBD and 20 clinically healthy dogs.

Methods

All CEUS studies of the duodenum were analyzed to obtain time‐intensity curves and perfusion parameters. The procedure was repeated in 12 IBD dogs 2 months after a standardized treatment.

Results

On CEUS, the duodenal wall showed a typical perfusion pattern characterized by a radial and simultaneous enhancement of the wall in all dogs. On qualitative assessment, no differences were observed in contrast medium distribution between healthy and affected dogs, or between dogs with IBD before and after treatment. Peak intensity (PI) and area under the curve (AUC) significantly differed between healthy (PI = 3.58 arbitrary units [au; 1.86‐4.93 au] and AUC = 47.63 au seconds [aus, 22.68‐62.15]) and affected dogs (PI = 5.10 au [0.63‐15.16 au] and AUC = 63.62 aus [5.31‐212.20 aus]; P = .03 and .03, respectively). No significant differences were found for the perfusion parameters before and after treatment.

Conclusions and Clinical Importance

We showed that CEUS allows discrimination between IBD affected dogs and healthy dogs by evaluation of time‐intensity curves, but did not provide useful information for monitoring therapeutic response. The qualitative assessment identified no significant differences between healthy and affected dogs, or between dogs before and after treatment.

CT measures of adrenal gland length and caudal pole diameter are reproducible in large breed dogs: A pilot study

Computed tomography (CT) is increasingly available to evaluate dogs with suspected adrenal disease, however, published studies describing the reproducibility of CT methods for quantifying adrenal gland (AG) measurements are lacking. This prospective, pilot, observer agreement study aimed to evaluate reproducibility and repeatability of two different methods of measurement of AGs on CT to establish a usable technique and define standard reference ranges. Multiplanar reformatted (MPR) CT images of both AGs of six large breed dogs were obtained with the MPR axis parallel to the spine and parallel to the long axis of the AG. Ten measurements were performed: maximal length and diameter at cranial and caudal poles on dorsal, sagittal, and transverse images; and minimal diameter of cranial and caudal poles on transverse images. Three observers with different levels of experience repeated these measurements three times for each dog. Intra‐ and interobserver variability were calculated through intraclass correlation coefficient (ICC). The differences in time to perform measurements between the two methods were tested with Student's t‐test. Regardless of the measurement method used, length of AGs on dorsal and sagittal MPR images had the lowest intra‐ and inter‐observer variability (ICC = 0.93‐0.99), diameter of caudal pole on transverse plane showed low intra‐ and interobserver variability (ICC = 0.77‐0.80) and diameter of cranial pole had the highest variability (ICC = 0.12‐0.61). Although length was the less variable measurement, its use may be unrealistic in daily practice. Interestingly measurement of caudal pole on transverse plane was characterized by low intra‐ and interobserver variability. No difference in time performing the measurements was noted between the two methods.

Prevalence and risk factors for atrial fibrillation in dogs with myxomatous mitral valve disease

Background

Atrial fibrillation (AF) is a common supraventricular arrhythmia more frequently observed in large breed dogs.

Objectives

Estimate the prevalence of AF in dogs with myxomatous mitral valve disease (MMVD) and identify risk factors for developing AF.

Animals

A total of 2194 client‐owned dogs with MMVD, including 1280, 588, 290, and 36 dogs in ACVIM stages B1, B2, C, and D, respectively.

Methods

Retrospective, cross‐sectional study. The medical databases of 3 veterinary teaching hospitals were reviewed. Inclusion criteria were a diagnosis of MMVD after complete cardiovascular evaluation and cardiac rhythm assessment using routine 2‐minute ECG or good quality ECG tracing during echocardiographic examination.

Results

Atrial fibrillation was diagnosed in 59 dogs with a prevalence of 2.7%. Univariate analysis showed that mixed breed, male sex, advanced ACVIM stage, left atrial and ventricular enlargement, fractional shortening (FS), and presence of pulmonary hypertension were significantly associated with development of AF. According to 2 multivariable models, the left atrium (LA)‐to‐aorta ratio (odds ratio [OR] = 14.011, 7.463‐26.304), early trans‐mitral velocity (OR = 2.204, 1.192‐4.076), body weight (OR = 1.094, 1.058‐1.130), and FS (OR = 0.899, 0.865‐0.934) and LA (OR = 5.28, 3.377‐8.092), advanced ACVIM stage (OR = 4.922, 1.481‐16.353), and FS (OR = 0.919, 0.881‐0.959) were significant predictors of AF for models 1 and 2, respectively.

Conclusions and Clinical Importance

Atrial fibrillation is an uncommon complication of MMVD and is significantly associated with the more advanced stage of the disease, increased LA dimension and body weight, and decreased FS.

Recommendations for standardized plane definition in canine cardiac MRI

With the growing interest in cardiac magnetic resonance imaging (cMRI), veterinary radiologists will increasingly be asked to use this modality to answer complex cardiological questions. Plane alignment is crucial for reproducible assessment of the heart. Anesthesia time is a limiting factor in cMRI. Aims of this prospective experimental study were to introduce a flow chart for standardized cMRI-examination in dogs, to test it for reproducibility using a cardiac CT simulation and to estimate time requirements needed to complete the examination accurately. Six operators (3 radiologists, 1 cardiologist, 1 imaging-resident, 1 technician) simulated a cMRI examination on CT-scans of 6 healthy Beagle dogs twice within two to four weeks. Assessment included qualitative and quantitative scoring of plane quality and time requirements. The quality of planes was high for the left and moderate for the right side of the heart. The intraclass correlation coefficient (ICC) of linear measurements of structures on the left was good to excellent (ICC-range: 0.789-0.948) but dropped to moderate to poor levels for the right side (ICC-range: 0.429-0.738). The median time required to complete a full examination was 30 (range: 13-103) min in the first and 24 (range: 15-62) min in the second evaluation. It differed significantly between operators and was consistently shorter for the left than for the right side. In conclusion, a new standardized scheme for cMRI can be quickly adopted by radiologists with some expertise in cross sectional imaging. Qualitative and quantitative results were highly reproducible for the left but less for the right side.

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

Background

Atrial fibrillation (AF) occurs in dogs with myxomatous mitral valve disease (MMVD) as a consequence of left atrial (LA) dilatation, and it affects survival and quality of life.

Objectives

To evaluate the usefulness of echocardiography in predicting the first occurrence of AF in dogs with MMVD.

Animals

Forty‐four client‐owned dogs with MMVD, 22 dogs that developed AF, and 22 dogs that maintained sinus rhythm.

Methods

Retrospective observational study. Medical databases were reviewed for dogs that developed AF during the year after diagnosis of MMVD (AF group). The last echocardiographic examination obtained while still in sinus rhythm was used to derive selected variables. For each dog with AF, a control dog matched for body weight, class of heart failure, and LA dimension was selected. Echocardiographic results including LA volumes and LA speckle tracking echocardiography (STE)‐derived variables were measured.

Results

Among the tested echocardiographic variables, only LA diameter (P = .03) and left ventricular internal diameter in diastole (P = .03) differed significantly between groups, whereas body weight‐indexed variables of cardiac dimension as well as LA volumes and volume‐derived functional variables were not different. Among the STE‐derived variables, peak atrial longitudinal strain (PALS) results differed significantly between the AF group (23.8% ± 8.6%) and the control group (30.5% ± 9.6%; P = .03). A value of PALS ≤28% predicted AF occurrence with sensitivity and specificity of 0.80 and 0.65, respectively.

Conclusions and Clinical Importance

Absolute cardiac diameters and LA STE (in particular, PALS) are useful echocardiographic predictors for the development of AF in dogs with MMVD.

Electrocardiographic and echocardiographic evaluation in dogs with hypothyroidism before and after levothyroxine supplementation: A prospective controlled study

Background

Improvement in cardiac function has been demonstrated after thyroxine treatment in humans with hypothyroidism using the myocardial performance index (MPI). Cardiac changes after thyroxine supplementation are poorly documented in dogs with spontaneous hypothyroidism and comparison with clinically healthy dogs is lacking.

Objectives

To evaluate the electrical activity and mechanical function of the heart in dogs with primary hypothyroidism at baseline (T0) and after thyroxine supplementation (T60).

Animals

Forty client‐owned dogs with hypothyroidism and 20 clinically healthy dogs.

Methods

Prospective cohort study. Selected electrocardiographic and echocardiographic variables, including the MPI, were measured in all dogs at T0 and in 30 hypothyroid dogs at T60.

Results

Hypothyroid dogs had significantly decreased median or mean heart rate (HR), P wave amplitude, and R wave amplitude (P = .04, P = .002, and P = .003, respectively) and E‐point‐to‐septal separation normalized to body weight (EPSSn) and trans‐mitral E wave velocity (E max; P < .001 and P = .025, respectively) at T0 compared to control dogs. At T60, significantly increased median or mean HR, P wave amplitude, fractional shortening, and E max (P < .001, P = .004, P = .002, and P = .009, respectively) and significantly decreased left ventricular end‐diastolic volume index, and normalized systolic diameter and EPSSn (P = .03, P = .03, and P = .001, respectively) were found.

Conclusions and Clinical Importance

Hypothyroidism in dogs induces mild and reversible changes of electromechanical cardiac function. The MPI does not have clinical importance in identifying cardiac dysfunction in affected dogs.

Variability among strain variables derived from two-dimensional speckle tracking echocardiography in dogs by use of various software

OBJECTIVE

To determine variability of global longitudinal strain (GLS) and strain rate (SR) measurements in dogs with and without cardiac disease derived from 2-D speckle tracking echocardiography (STE) by use of various software.

ANIMALS

2 cohorts comprising 44 dogs (23 cardiovascularly healthy and 21 with cardiac disease) and 40 dogs (18 cardiovascularly healthy and 22 with cardiac disease).

PROCEDURES

Transthoracic echocardiographic images in each cohort were analyzed with vendor-independent software and vendor-specific 2-D STE software for each of 2 vendors. Values for GLS and SR obtained from the same left parasternal apical views with various software were compared. Intraobserver and interobserver variability was determined, and agreement among results for the various software was assessed.

RESULTS

Strain analysis was not feasible with vendor-independent software for 20% of images obtained with the ultrasonography system of vendor 1. Intraobserver and interobserver coefficient of variation was < 10% for GLS values, whereas SR measurements had higher variance. There was a significant difference in GLS and SR obtained for each cohort with different software. Evaluation of Bland-Altman plots revealed wide limits of agreement, with variance for GLS of up to 6.3 units in a single dog.

CONCLUSIONS AND CLINICAL RELEVANCE

Results of longitudinal strain analysis were not uniform among software, and GLS was the most reproducible measurement. Significant variability in results among software warrants caution when referring to reference ranges or comparing serial measurements in the same patient because changes of < 6.5% in GLS might be within measurement error for different postprocessing software.

Two-dimensional and contrast-enhanced ultrasound of intestinal ischaemia in cats: four cases

OBJECTIVES

The aim of this study was to describe the results of two-dimensional (2D) and contrast-enhancement ultrasound (CEUS) in four cats with intestinal ischaemia.

METHODS

Data were collected from hospital records of all cats that had intestinal ischaemia between January 2012 and August 2018. The inclusion criteria were complete abdominal ultrasound examination, colour flow Doppler and CEUS of lesions, confirmation of intestinal ischaemia detected by visual assessment of avascular intestinal segment at surgery, and/or necropsy and histopathology. All images and video clips were reviewed by the same experienced operator.

RESULTS

Four cats with different intestinal ischaemic lesions were included in the study: duodenal perforating ulcer, jejunal necrotising enteritis, necrosis secondary to jejunojejunal intussusception and iatrogenic damage of jejunal arteries. On the 2D ultrasound, all intestinal lesions were characterised by non-specific findings: focal hypoechoic wall thickening with loss of normal layering associated with hyperechoic mesentery surrounding the intestinal tract. CEUS showed a reduced or absent enhancement of the intestinal lesions in comparison to the surrounding perfused wall.

CONCLUSIONS AND RELEVANCE

Intestinal ischaemia is a potentially fatal disorder. Grey-scale, colour and power Doppler ultrasonography are not sensitive for evaluating this condition. Our preliminary findings illustrate the usefulness of CEUS for the detection of intestinal wall impaired perfusion in cats.

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.

Vidatox 30 CH has tumor activating effect in hepatocellular carcinoma

Complementary and alternative medicine (CAM) is the term used to describe many kinds of products, practices, and systems that are not part of conventional medicine. Cancer patients usually do everything they can to combat the disease, manage its symptoms, and cope with the side effects of treatment. Unfortunately, patients who use CAM underestimate the risk of interaction with cancer therapy or worse they omit conventional therapy thus reducing the possibility of cancer remission. Herein we analyzed the effects of Vidatox 30 CH (venom extracted from the Junceus Rhopalurus scorpion) on hepatocellular carcinoma (HCC), the second leading cause of cancer-related deaths. We found out that Vidatox increases HCC proliferation and invasion whereas it does not seem to interact with sorafenib, the orally active multikinase inhibitor approved for the treatment of advanced hepatocellular carcinoma. Our results suggest that the concentration of Vidatox used in the present study has not anti-neoplastic effects and care must be taken in hiring Vidatox in patients with HCC.

Sensitivity, specificity, and interobserver variability of survey thoracic radiography for the detection of heart base masses in dogs

OBJECTIVE To determine the sensitivity, specificity, and interobserver variability of survey thoracic radiography (STR) for the detection of heart base masses (HBMs) in dogs. DESIGN Retrospective case-control study. ANIMALS 30 dogs with an HBM and 120 breed-matched control dogs (60 healthy dogs and 60 dogs with heart disease and no HBM). PROCEDURES In a blinded manner, 2 observers (designated as A and B) evaluated STR views from each dog for a mass-like opacity cranial to the heart, tracheal deviation, cardiomegaly, findings suggestive of pericardial effusion or right-sided congestive heart failure, and soft tissue opacities suggestive of pulmonary metastases. Investigators subsequently provided a final interpretation of each dog's HBM status (definitely affected, equivocal, or definitely not affected). RESULTS Considering equivocal interpretation as negative or positive for an HBM, the sensitivity of STR for diagnosis of an HBM was 40.0% (95% confidence interval [CI], 22.5% to 57.5%) and 56.7% (95% CI, 38.9% to 74.4%), respectively, for observer A and 63% (95% CI, 46.1% to 80.6%) and 80.0% (95% CI, 65.7% to 94.3%), respectively, for observer B. The corresponding specificity was 96.7% (95% CI, 93.5% to 99.9%) and 92.5% (95% CI, 87.8% to 97.2%), respectively, for observer A and 99.2% (95% CI, 97.5% to 100%) and 92.5% (95% CI, 87.8% to 97.2%), respectively, for observer B. The presence of a mass-like opacity cranial to the heart or tracheal deviation, or both, was significantly associated with a true diagnosis of HBM. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that STR is a highly specific but not a highly sensitive predictor of HBM in dogs.

In Hepatocellular Carcinoma miR-221 Modulates Sorafenib Resistance through Inhibition of Caspase-3-Mediated Apoptosis

Purpose: The aberrant expression of miR-221 is a hallmark of human cancers, including hepatocellular carcinoma (HCC), and its involvement in drug resistance, together with a proved in vivo efficacy of anti-miR-221 molecules, strengthen its role as an attractive target candidate in the oncologic field. The discovery of biomarkers predicting the response to treatments represents a clinical challenge in the personalized treatment era. This study aimed to investigate the possible role of miR-221 as a circulating biomarker in HCC patients undergoing sorafenib treatment as well as to evaluate its contribution to sorafenib resistance in advanced HCC.Experimental Design: A chemically induced HCC rat model and a xenograft mouse model, together with HCC-derived cell lines were employed to analyze miR-221 modulation by Sorafenib treatment. Data from the functional analysis were validated in tissue samples from surgically resected HCCs. The variation of circulating miR-221 levels in relation to Sorafenib treatment were assayed in the animal models and in two independent cohorts of patients with advanced HCC.Results: MiR-221 over-expression was associated with Sorafenib resistance in two HCC animal models and caspase-3 was identified as its target gene, driving miR-221 anti-apoptotic activity following Sorafenib administration. Lower pre-treatment miR-221 serum levels were found in patients subsequently experiencing response to Sorafenib and an increase of circulating miR-221 at the two months assessment was observed in responder patients.Conclusions: MiR-221 might represent a candidate biomarker of likelihood of response to Sorafenib in HCC patients to be tested in future studies. Caspase-3 modulation by miR-221 participates to Sorafenib resistance. Clin Cancer Res; 23(14); 3953-65. ©2017 AACR.

Non-invasive evaluation of the haemodynamic effects of high-dose medetomidine in healthy cats for semen collection

OBJECTIVES

This study aimed to assess non-invasively the cardiovascular effects of high-dose medetomidine on healthy male cats undergoing semen collection.

METHODS

Haemodynamic evaluations were assessed on the basis of clinical examination, systolic arterial pressure (SAP) and transthoracic echocardiographic examination. Eight client owned, male domestic shorthair cats were sedated with a bolus of medetomidine intramuscularly (IM; 0.13 mg/kg), and semen collection was performed. A second transthoracic echocardiographic examination and SAP measurement were carried out 15 mins after sedation. At the end of the examination, the patients received a bolus of atipamezole (0.3 mg/kg) IM.

RESULTS

The cats were deeply sedated, relaxed and laterally recumbent during the entire procedure. No rhythm abnormalities were observed during the examinations and no significant increase in SAP was recorded. Heart rate dropped from 200 ± 33 to 92 ± 13.1 beats per min after sedation. There was a significant increase in left ventricular dimensions and the left atrial area. The parameters of left ventricular systolic function were reduced, as were systemic and pulmonary cardiac outputs. Peak diastolic wave velocities were significantly reduced, while isovolumic contraction and relaxation time of the left ventricle were prolonged. Aortic valve insufficiency was recorded for all cats, while mitral valve insufficiency was noted in five cats. None of the subjects developed systolic anterior motion of the mitral valve.

CONCLUSIONS AND RELEVANCE

The protocol allowed us to collect good semen samples in healthy cats. However, high-dose medetomidine induces significant haemodynamic effects on the feline heart, mainly due to a reduced heart rate, an increased cardiac preload and impaired systolic function. The animals recovered from the anaesthesia, after antagonist administration, without showing any clinically relevant consequences.

Contrast-enhanced ultrasonography of the pancreas in healthy cats

BACKGROUND

This study describes the pattern of ultrasonographic contrast enhancement of the pancreatic body and left lobe using a second-generation commercial contrast medium (Sonovue) in 10 clinically healthy cats.

RESULTS

Following contrast medium administration, microbubbles were observed within the splenic artery. This was followed by an inflow of contrast medium into the pancreatic capillary beds, providing a uniformly contrast-enhanced pancreas at peak intensity (PI). At the time of PI, a replenishment of the splenic and portal veins started and increased progressively during the wash-out phase. During the wash-out phase, the echogenicity of the pancreatic parenchyma decreased progressively. Perfusion parameters included arrival time (4.69 ± 1.26 s), time to peak from injection (7.52 ± 1.88 s), time to peak from initial rise (2.84 ± 0.88 s), peak intensity (6.58 ± 2.66 a.u.), and wash-in rate (2.11 ± 1.79 a.u./s).

CONCLUSIONS

This perfusion pattern of normal pancreatic parenchyma may be useful for characterising cats with exocrine pancreatic disorders.

Notch3 inhibition enhances sorafenib cytotoxic efficacy by promoting GSK3b phosphorylation and p21 down-regulation in hepatocellular carcinoma

Sorafenib (Nexavar), a multiple kinase inhibitor, is the only clinically approved drug for patients with advanced HCC. However, its therapeutic success is limited by the emergence of drug resistance. Here we found that p21 and pGSK3β^Ser9 are major players in the resistance to sorafenib. We recently reported that aberrant Notch3 expression in HCC contributes to doxorubicin resistance in vitro and, therefore, we focused on the mechanisms that associate Notch3 to acquired drug resistance. In this study we first found that Notch3 inhibition significantly increased the apoptosis inducing effect of sorafenib in HCC cells via specific down-regulation of p21 and up-regulation of pGSK3β^Ser9. Using a mouse xenograft model we further found that Notch3 depletion combined with 21 days of sorafenib treatment exerts a substantial antitumor effect in vivo. Interestingly, we showed that, upon exposure to sorafenib treatment, Notch3 depleted xenografts maintain lower levels of p21 and higher levels of pGSK3β^Ser9 than control xenografts. Thus, this study demonstrated that inhibition of Notch3 signaling prevents HCC-mediate drug resistance and sensitizes HCC cells to sorafenib. Finally, we validated our in vitro and in vivo results in primary human HCCs showing that Notch3 protein expression positively correlated with p21 protein expression and negatively correlated with pGSK3β^Ser9 expression. In conclusion, the results presented in this study demonstrated that Notch3 silencing enhances the effect of sorafenib by overcoming drug resistance. Notch3 inhibition in combination with sorafenib can be a promising strategy for treatment of HCC.

Evaluation of the impact of transient interruption of antiangiogenic treatment using ultrasound-based techniques in a murine model of hepatocellular carcinoma

Background

Development of escape pathways from antiangiogenic treatments was reported to be associated with enhanced tumor aggressiveness and rebound effect was suggested after treatment stop. Aim of the study was to evaluate tumor response simulating different conditions of administration of antiangiogenic treatment (transient or definitive treatment stop) in a mouse model of hepatocellular carcinoma.

Methods

Subcutaneous tumors were created by inoculating 5×10⁶ Huh7 cells into the right flank of 14 nude mice. When tumor size reached 5–10 mm, mice were divided in 3 groups: group 1 was treated with placebo, group 2 was treated with sorafenib (62 mg/kg via gavage) but temporarily suspended from day +5 to +9, whereas in group 3 sorafenib was definitively stopped at day +5. At day +13 all mice were sacrificed, collecting masses for Western-Blot analyses. Volume was calculated with B-mode ultrasonography at day 0, +5, +9, +11 and +13. VEGFR2-targeted contrast-enhanced ultrasound using BR55 (Bracco Imaging) was performed at day +5 and +13 and elastonosography (Esaote) at day +9 and +11 to assess tumor stiffness.

Results

Median growth percentage delta at day +13 versus day 0 was 197% (115–329) in group 1, 81% (48–144) in group 2 and 111% (27–167) in group 3. Median growth delta at day +13 with respect to day +5 was 79% (48–127), 37% (−14128) and 81% (15–87) in groups 1, 2 and 3, respectively. Quantification of targeted-CEUS at day +13 showed higher values in group 3 (509 Arbitrary Units AI, range 293–652) than group 1 (275 AI, range 191–494) and group 2 (181 AI, range 63–318) (p = 0.033). Western-Blot analysis demonstrated higher VEGFR2 expression in group 3 with respect to group 1 and 2.

Conclusions

A transient interruption of antiangiogenic treatment does not impede restoration of tumor response, while a definitive interruption tends to stimulate a rebound of angiogenesis to higher level than without treatment.

Diagnostic accuracy of the vertebral heart score and other radiographic indices in the detection of cardiac enlargement in cats with different cardiac disorders

A retrospective search was conducted to evaluate the diagnostic accuracy of the vertebral heart score (VHS) and other related radiographic indices in the detection of cardiac enlargement associated with different cardiac disorders in the cat. One hundred and five cats with a complete echocardiographic examination and radiographic examination of the thorax with at least two orthogonal views were enrolled. Eighty-three cats had different cardiac disorders, 72 with left-sided cardiac disorders (LSCD) and 11 with right-sided cardiac disorders; 22 cats were free of cardiovascular abnormalities. Measurements of VHS and cardiac long and short axes on lateral (L) and dorsoventral or ventrodorsal radiographs were obtained. Receiver operating characteristic curves were calculated to evaluate the diagnostic accuracy of each radiographic index in differentiating between cats with cardiac disorders or cats with LSCD and cats without cardiac abnormalities and, among cats with LSCD, between those with no or mild left atrial enlargement (LAE) or those with moderate-to-severe LAE and healthy cats. The L-VHS at the cut-off of 7.9 had high diagnostic accuracy in distinguishing cats with LSCD and moderate-to-severe LAE from healthy cats, but all the other radiographic indices were moderately accurate in distinguishing between cats with overall cardiac disorders or LSCD, either with no or mild LAE and moderate-to-severe LAE, and healthy cats. The considered radiographic indices were also moderately accurate in predicting different degrees of LAE in cats with LSCD. Radiographic indices are reasonably specific, but less sensitive predictors of cardiac enlargement in cats with heart disorders.

Accuracy of radiographic vertebral heart score and sphericity index in the detection of pericardial effusion in dogs

OBJECTIVE

To evaluate the diagnostic accuracy of radiographically derived measurements of vertebral heart score (VHS) and sphericity index (SI) in the detection of pericardial effusion (PE) in dogs.

DESIGN

Retrospective case-control study. Animals-51 dogs with PE associated with various cardiac disorders, 50 dogs with left- or right-sided cardiac disorders without PE, 50 dogs with bilateral cardiac disorders without PE, and 50 healthy dogs.

PROCEDURES

Measurements of VHS on lateral (lateral VHS) and ventrodorsal (ventrodorsal VHS) radiographs, SI on lateral (lateral SI) and ventrodorsal (ventrodorsal SI) radiographs, and global SI (mean of lateral SI and ventrodorsal SI) were obtained. Receiver operating characteristic curves were calculated to evaluate the diagnostic accuracy of the radiographic indexes at differentiating dogs with PE from those with other cardiac disorders without PE.

RESULTS

Measurements of lateral and ventrodorsal VHS were significantly higher in dogs with PE, compared with values for all dogs without PE. Measurements of lateral, ventrodorsal, and global SI were significantly lower in dogs with PE, compared with values for all dogs without PE. Cutoff values of > 11.9, > 12.3, and ≤ 1.17 for lateral VHS, ventrodorsal VHS, and global SI, respectively, were the most accurate radiographic indexes for identifying dogs with PE.

CONCLUSIONS AND CLINICAL RELEVANCE

Cardiac silhouettes of dogs with PE were larger and more rounded, compared with those of dogs with other cardiac disorders without PE. Objective radiographic indexes of cardiac size and roundness were only moderately accurate at distinguishing dogs with PE from dogs with other cardiac disorders without PE.

Imaging diagnosis-cholangiocellular adenoma: contrast-enhanced ultrasonographic findings of a benign tumor mimicking malignant neoplasia in a dog

A 9-year-old Giant Schnauzer was referred for polyuria and polydipsia. On abdominal ultrasound, a hyperechoic mass with low color Doppler signal was detected in the medial right hepatic lobe. Contrast-enhanced ultrasound (CEUS) demonstrated increased enhancement of the mass during the arterial phase, and contrast washout during portal and late phases with decreased enhancement relative to the liver. These findings were consistent with primary liver malignancy or liver metastasis. A final diagnosis of cholangiocellular adenoma was made based on histopathology. To our knowledge, this is the first description of a benign hepatic neoplasm exhibiting malignant CEUS characteristics in a dog.

Improved sorafenib activity on hepatocellular carcinoma in Notch3 silenced in vivo and in vitro models

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Background: Sorafenib is the only approved drug for the treatment of the advanced stage of HCC. Although its efficacy has been proven with randomized clinical trials, the clinical benefit seen in overall survival for advanced HCC patients treated with sorafenib could be improved. New molecules or combination of novel targeted agents to improve sorafenib efficacy for advanced stage HCC patients are needed. Notch genes are a family of receptors involved in many cell fate regulations, their expression has been found altered in many tumors, including HCC. The aim of this study was to study the combination of sorafenib and Notch3 signaling inhibition to improve sorafenib’s therapeutic effect. Methods: HepG2 and Huh7 cellular models were used for Notch3 stable silencing by retroviral introduction of specific interfering RNAs Xenograft models in both Notch3 stable shRNA cell lines have been developed using NOD/SCID mice. Animals bearing tumors were treated with 60 mg/kg of sorafenib for 21 consecutive days. Notch3, p21 and pGSK3βSer9 protein expression were also analyzed in 20 human HCCs. Results: Notch3 silencing (shN3) in HuH7 and HepG2 cell lines treated with sorafenib showed an increase in cell death (3.8 to 5 fold increase) when shN3 cell lines were compared with their relative controls (GL2). A difference in tumor growth was observed between GL2 negative control vs shN3 xenografts in both HepG2 and Huh7 after 21 days of sorafenib treatment. Two tailed student’s t test (shN3 vs GL2) P=0,04 and P=0,01 for Huh7 and HepG2 respectively. Molecular investigations have shown the involvement of p21 and GSK3β in the enhanced response to sorafenib in Notch 3 silenced models. A significant inverse correlation between Notch3 and pGSK3βSer9 proteins accumulation (Spearman ρ= -0.666) (p < 0.01) and a direct correlation between Notch3 and p21 proteins expression (Spearman ρ= 0.681) (p < 0.01) was found in HCC samples obtained from patients. Conclusion: Our preclincal findings outline the effect of combined Notch3 inhibition and sorafenib. The molecular mechanisms responsible for sorafenib induced cell death associated with Notch3 silencing relays on inhibition of p21/CDKN1A and GSK3βSer9. This study is supported by a grant from Bayer Healthcare, Italy.

Orthodromic atrioventricular reciprocating tachycardia conducted with intraventricular conduction disturbance mimicking ventricular tachycardia in an English Bulldog

Electrocardiographic tracings of an English Bulldog referred for cardiogenic shock due to an orthodromic atrioventricular reciprocating tachycardia conducted with intraventricular conduction disturbance and mimicking ventricular tachycardia (VT) are presented. At admission the surface ECG showed a wide QRS complex tachycardia (WCT) that was converted to sinus rhythm using manual cardioversion (chest thump). This change revealed pre-existing right bundle branch block, and a final diagnosis of supraventricular tachycardia (SVT) with intraventricular conduction disturbance was made. Electrophysiologic study defined the SVT mechanism as an atrioventricular macroreentrant tachycardia mediated by a single mid-septal accessory pathway. The differentiation between various types of WCT is essential when antiarrhythmic therapy is considered. The surface ECG should be systematically evaluated in order to recognize the characteristic features of SVT and VT. Moreover chest thump procedure can be very helpful in the attempt to convert the rhythm to sinus rhythm and to correctly recognize the underlying arrhythmia.

Contrast-enhanced ultrasonography of the small bowel in healthy cats

We characterized the pattern of ultrasonographic contrast enhancement of the small intestinal wall using a commercial contrast medium (Sonovue(®) ) in 10 healthy awake cats. Subjectively, a rapid intense enhancement of the serosal and submucosal layers was followed by gradual enhancement of the entire wall section during the early phase. At peak enhancement, there was a subjective loss of demarcation between intestinal wall layers. In the late phase, there was a gradual wash out of signal from the intestinal wall. Submucosal wash out occurred last. Time-intensity curves were generated for selected regions in the intestinal wall and multiple perfusion parameters were calculated for each cat. Perfusion parameters included arrival time (7.64 ± 2.23 s), baseline intensity (1.04 ± 0.04 a.u.), time to peak from injection (10.74 ± 2.08 s), time to peak from initial rise (3.1 ± 1.15), peak intensity (8.92 ± 3.72 a.u.), wash-in rate (2.06 ± 0.70 a.u./s) and wash-out rate (-1.07 ± 0.91 a.u./s). The perfusion pattern of normal feline small bowel may be useful for characterizing feline gastrointestinal disorders that involve the intestinal wall.