Myocardial injury in dogs: a retrospective analysis on etiological, echocardiographic, electrocardiographic, therapeutic, and outcome findings in 102 cases.

INTRODUCTION: In dogs, myocardial injury (MI) is a poorly characterized clinical entity; therefore, this study aimed to provide a detailed description of dogs affected by this condition. ANIMALS, MATERIALS, AND METHODS: Dogs diagnosed with MI according to the concentration of cardiac troponin I (cTnI) were retrospectively searched. Signalment, diagnostic, therapeutic, and outcome data were retrieved. Dogs were divided into six echocardiographic (dilated cardiomyopathy phenotype; hypertrophic cardiomyopathy phenotype; hypertrophic cardiomyopathy phenotype with systolic dysfunction; abnormal echogenicity only; endocarditis; and no echocardiographic abnormalities suggestive of MI), four electrocardiographic (abnormalities of impulse formation; abnormalities of impulse conduction; abnormalities of ventricular repolarization; and no electrocardiographic abnormalities suggestive of MI), and nine etiological (infective; inflammatory; neoplastic; metabolic; toxic; nutritional; immune-mediated; traumatic/mechanical; and unknown) categories. Statistical analysis was performed to compare cTnI values among different categories and analyze survival. RESULTS: One hundred two dogs were included. The median cTnI value was 3.71 ng/mL (0.2-180 ng/mL). Echocardiographic and electrocardiographic abnormalities were documented in 86 of 102 and 89 of 102 dogs, respectively. Among echocardiographic and electrocardiographic categories, the dilated cardiomyopathy phenotype (n = 52) and abnormalities of impulse formation (n = 67) were overrepresented, respectively. Among dogs in which a suspected etiological trigger was identified (68/102), the infective category was overrepresented (n = 20). Among dogs belonging to different echocardiographic, electrocardiographic, and etiological categories, cTnI did not differ significantly. The median survival time was 603 days; only eight of 102 dogs died due to MI. CONCLUSIONS: Dogs with MI often have an identifiable suspected trigger, show various echocardiographic and electrocardiographic abnormalities, and frequently survive to MI-related complications.

Suspected sequential left atrial ruptures in a dog with myxomatous mitral valve disease.

An 11-year-old mixed breed dog was presented with exercise intolerance and syncope. At admission, transthoracic echocardiography revealed myxomatous mitral valve disease (MMVD) associated with severe left atrial (LA) enlargement and moderate anechoic pericardial effusion with a hyperechoic density suggestive of a thrombus. Rupture of the LA free wall secondary to MMVD was suspected, and medical therapy with furosemide and pimobendan was initiated. After one month, recheck echocardiography showed mild anechoic pericardial effusion and an acquired atrial septal defect with a left-to-right intracardiac shunting flow. In light of the dog's history, the latter finding was suspected to be secondary to a further rupture of the LA wall due to MMVD, this time affecting the interatrial septum. The images described here allow us to suspect that sequential LA wall ruptures developed over time in the same subject affected by MMVD, a clinical presentation not previously described in veterinary medicine.

Electrocardiographic, echocardiographic, and left atrial strain imaging features of a dog with atrial flutter and third-degree atrioventricular block.

A 14-year-old American Staffordshire terrier was presented for episodes of exercise-induced syncope. At admission, atrial flutter coupled to third-degree atrioventricular block was diagnosed electrocardiographically. On the second day of hospitalization, surface electrocardiogram revealed spontaneous conversion to sinus rhythm with persistence of atrioventricular block. Complete transthoracic echocardiograms were performed after each electrocardiographic examination. The combined use of conventional echocardiography with tissue Doppler imaging-based modalities allowed to investigate the atrial electromechanical correlation and function during typical atrial flutter and after its resolution.

The feasibility of contrast enhanced ultrasonography (CEUS) in the diagnosis of non-cardiac thoracic disorders of dogs and cats.

BACKGROUND: This study describes the feasibility of Contrast Enhanced Ultrasonography (CEUS) in the diagnostic work-up of non-cardiac thoracic disorders of small animals. The second aim is to assess the usefulness of CEUS as a direct guide for sample procedures. RESULTS: Forty animals, 28 dogs and 12 cats, were included in the study. Thoracic disorders included 23 pulmonary lesions [primary carcinoma (14), lymphoma (1), sarcoma (1), histiocytic sarcoma (1), abscess (1) and pneumonia (5)] and 17 mediastinal lesions [lymphoma (8), thymoma (3), mesothelioma (1), melanoma (1), carcinomatous lymphadenopathy (1), mixsosarcoma (1), lipoma (1), and abscess (1)]. The majority of neoplastic pulmonary lesions showed an inhomogeneous distribution of contrast medium, whereas inflammatory lesions had a homogenous distribution with typical pulmonary vessels ramification. The majority of mediastinal malignant lesions showed an inhomogeneous distribution pattern. The lung and mediastinal abscesses had peripheral enhancement of the wall with an avascular center. All cytological and biopsy samples obtained after CEUS were diagnostic. Quantitative analysis, performed in 19/23 pulmonary lesions, showed a statistically significant difference (P < 0.0001) between the arrival time of the malignant (7.27 s - range 4.46-13.52 s) and benign (4.52 s - range 2.87-6.06 s) pulmonary lesions. CONCLUSIONS: CEUS may be a useful tool for the evaluation of non-cardiac thoracic lesions. The contrast medium allows for the precise definition of lesion edges, the presence of necrotic areas, and the distribution of pulmonary vessels. Based on our preliminary results, the use of ultrasonographic contrast medium can be recommended for improving the diagnostic usefulness of cytology and biopsy sampling, because CEUS may help to define necrotic areas from viable tissue.

Assessment of Left Atrial Deformation and Function by 2-Dimensional Speckle Tracking Echocardiography in Healthy Dogs and Dogs With Myxomatous Mitral Valve Disease.

BACKGROUND: The assessment of left atrial (LA) function by 2-dimensional speckle tracking echocardiography (STE) holds important clinical implications in human medicine. Few similar data are available in dogs. OBJECTIVES: To assess LA function by STE in dogs with and without myxomatous mitral valve disease (MMVD), analyzing LA areas, systolic function, and strain. ANIMALS: One hundred and fifty dogs were divided according to the American College of Veterinary Internal Medicine classification of heart failure: 23 dogs in class A, 52 in class B1, 36 in class B2, and 39 in class C + D. METHODS: Prospective observational study. Conventional morphologic and Doppler variables, LA areas, and STE-based LA strain analysis were performed in all dogs and results were compared among groups. Correlation analysis was carried out between LA STE variables and other echocardiographic variables. RESULTS: Variability study showed good reproducibility for all the tested variables (coefficient of variation <16%). Left atrial areas, fractional area change, peak atrial longitudinal strain (PALS), peak atrial contraction strain, and contraction strain index (CSI) differed significantly between groups B2 and C + D and all the other groups (overall P < .001), whereas only PALS differed between groups B1 and A (P = .01). Left atrial areas increased with progression of the disease, whereas LA functional parameters decreased. Only CSI increased nonsignificantly from group A to group B1 and then progressively decreased. Thirty-one significant correlations (P < .001, r > .3) were found between conventional left heart echocardiographic variables and LA areas and strain variables. CONCLUSIONS AND CLINICAL IMPORTANCE: Left atrial STE analysis provides useful information on atrial function in the dog, highlighting a progressive decline in atrial function with worsening of MMVD.

Utility of Tissue Doppler Imaging in the Echocardiographic Evaluation of Left and Right Ventricular Function in Dogs with Myxomatous Mitral Valve Disease with or without Pulmonary Hypertension.

BACKGROUND: In human medicine, right ventricular (RV) functional parameters represent a tool for risk stratification in patients with congestive heart failure caused by left heart disease. Little is known about RV alterations in dogs with left-sided cardiac disorders. OBJECTIVES: To assess RV and left ventricular (LV) function in dogs with myxomatous mitral valve disease (MMVD) with or without pulmonary hypertension (PH). ANIMALS: One-hundred and fourteen dogs: 28 healthy controls and 86 dogs with MMVD at different stages. METHODS: Prospective observational study. Animals were classified as healthy or having MMVD at different stages of severity and according to presence or absence of PH. Twenty-eight morphological, echo-Doppler, and tissue Doppler imaging (TDI) variables were measured and comparison among groups and correlations between LV and RV parameters were studied. RESULTS: No differences were found among groups regarding RV echo-Doppler and TDI variables. Sixteen significant correlations were found between RV TDI and left heart echocardiographic variables. Dogs with PH had significantly higher transmitral E wave peak velocity and higher E/e' ratio of septal (sMV) and lateral (pMV) mitral annulus. These 2 variables were found to predict presence of PH with a sensitivity of 84 and 72%, and a specificity of 71 and 80% at cut-off values of 10 and 9.33 for sMV E/e' and pMV E/e', respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: No association between variables of RV function and different MMVD stage and severity of PH could be detected. Some relationships were found between echocardiographic variables of right and left ventricular function.

Early prediction of treatment response to sorafenib with elastosonography in a mice xenograft model of hepatocellular carcinoma: a proof-of-concept study.

PURPOSE: Sorafenib is the reference therapy for advanced hepatocellular carcinoma (HCC). There is no method for predicting in the early period subsequent individual response. Starting from the clinical experience in humans that subcutaneous metastases may rapidly change consistency under sorafenib and that elastosonography allows assessment of tissue elasticity, we investigated the role of this ultrasound-based technique in the early prediction of tumor response to sorafenib in a HCC mice model. MATERIALS AND METHODS: HCC subcutaneous xenografting in mice was utilized. Mice were randomized to vehicle (17 mice) or treatment with sorafenib (19 mice). Strain elastosonography (Esaote, Italy) of the tumor mass was performed at different time points (day 0, + 2 and + 14 from treatment start) until the mice were sacrificed (day + 14). At the same time points, the volume was calculated with ultrasonography. RESULTS: Sorafenib-treated mice showed a smaller increase in tumor size on day + 14 in comparison to vehicle-treated mice (tumor volume increase + 175 % vs. + 382 %, p = 0.009). The median tumor elasticity increased in both groups on day + 2 (+ 5.65 % and + 3.86 %, respectively) and decreased on day + 14 (-3.86 % and -3.63 %, respectively). However, among Sorafenib-treated tumors, 13 mice with a growth percentage delta < 200 % (considered as good treatment response) showed an increase in elasticity on day + 2 (+ 8.9 %, range -12.6 - + 64) while the other 6 with a growth percentage delta > 300 % (considered as poor treatment response) showed a decrease in elasticity (-17 %, range -30.2 - + 15.3) (p = 0.044). CONCLUSION: Elastosonography appears to be a promising noninvasive new technique for the early treatment prediction of HCC tumor response to sorafenib. Specifically, an early increase in tumor elasticity (corresponding to tumors becoming softer) is associated with a good response.

Reversible pulmonary hypertension in a cat.

A 13-year-old, neutered female domestic shorthair cat was presented for sudden respiratory distress following palliative radiotherapy and the combined administration of a single dose of carboplatin for the treatment of recurrent fibrosarcoma. Clinical and radiographic findings were suggestive of pleural effusion. Echocardiography revealed marked right-sided cardiac enlargement associated with tricuspid regurgitation and Doppler evidence of pulmonary hypertension. After 25 days of treatment for congestive heart failure and suspected pulmonary thromboembolism, clinical signs and echocardiographic and Doppler evidence of right-sided cardiac enlargement and pulmonary hypertension had completely resolved. To the best of the authors' knowledge, this is the first report of reversible pulmonary hypertension, likely secondary to pulmonary thromboembolism, in a cat.

Atrial septal defect in five dogs.

The clinical, electrocardiographic, radiographic, and two-dimensional, M-mode and Doppler echocardiographic findings of five cases of canine ostium secundum type atrial septal defect (ASD) are described. The atrial septal anomaly was associated with other congenital cardiac abnormalities in two dogs: ventricular septal defect in one case and tricuspid dysplasia in the other. ASD was found in addition to dilated cardiomyopathy and suspected atrial thrombosis in one geriatric dog, but was the only cardiac abnormality detected in the remaining two dogs. Colour Doppler imaging facilitated the diagnosis of ASD in all subjects. The long-term prognosis for dogs with isolated and small-sized ASD is usually good, but can be compromised by the presence of concurrent congenital or acquired cardiac diseases.

Equine muscular dystrophy with myotonia.

OBJECTIVES: To describe a case of equine muscular dystrophy with myotonia. METHODS: A 5-year-old horse presented with hypertrophy and delayed relaxation of the muscles of the hindlimbs from age 2 months. Testicular atrophy developed from 2 years of age. Action and percussion myotonia was associated with weakness in these muscles, and EMG showed diffuse myotonic discharges and myopathic features. Biopsy of the gluteal muscle showed adipose and connective tissue infiltration, marked variation in muscle fibre size, and moth-eaten, ring and whorled fibres. RESULTS: Injection of apamin, a peptide blocker of calcium-activated potassium channels, which inhibits myotonia in human myotonic dystrophy, was ineffective in blocking myotonic discharges. Discharges promptly abated with 2% lidocaine injection. CONCLUSIONS: Myotonia in this horse is associated with dystrophic changes similar to human myotonic dystrophy, though there are some pharmacological differences.

Ki-67 antigen expression in lymphocytes of cattle infected with bovine leukemia virus (BLV).

The Ki-67 monoclonal antibody, which recognizes an antigen present on the nuclear membrane surface of mammalian cells in the replication phase, has been used for the determination of the cellular cycle of peripheral blood lymphocytes on a group of cattle positive for bovine leukemia virus (BLV) and with blood values showing a persistent lymphocytosis. The results obtained have shown that: 1. Both of the techniques used (immunofluorescence and immunoperoxidase) are easily applicable and give uniform results; 2. Cattle with a persistent lymphocytosis show an absolute number of cells in cycle significantly more elevated compared with cattle positive for BLV with normal blood values.

S-phase evaluation with bromodeoxyuridine in lymphocytes from cattle infected with bovine leukemia virus (BLV).

Bromodeoxyuridine (BrdUrd), an analogue of thymidine, can be detected by means of monoclonal antibodies and utilized as a marker of the S-phase. In this paper a determination of the S-phase in BLV+ cattle with lymphocytosis has been performed by incorporating bromodeoxyuridine in the DNA. This evaluation was compared to the DNA content, demonstrating that i) bromodeoxyuridine incorporation is a reliable marker of S-phase in BLV+ cattle with lymphocytosis and ii) cytofluorimetry is the method of choice, together with immunocytochemistry, to demonstrate bromodeoxyuridine incorporation.