Assessing the use of blood microRNA expression patterns for predictive diagnosis of myxomatous mitral valve disease in dogs.

Background: Myxomatous mitral valve disease (MMVD) is a common, acquired, and progressive canine heart disease. The presence of heart murmur and current cardiac biomarkers are useful in MMVD cases but are not sufficiently discriminatory for staging an individual patient.

Objectives: This study aimed to conduct a preliminary assessment of canine serum and plasma expression profiles of 15 selected miRNA markers for accurate discrimination between MMVD patients and healthy controls.

Restoring Atrial T-Tubules Augments Systolic Ca Upon Recovery From Heart Failure.

Background: Transverse (t)-tubules drive the rapid and synchronous Ca rise in cardiac myocytes. The virtual complete atrial t-tubule loss in heart failure (HF) decreases Ca release. It is unknown if or how atrial t-tubules can be restored and how this affects systolic Ca.

Double-Outlet Right Atrium in a Young Cat.

• DORA is a rare variant of endocardial cushion defect reported in both people and cats. • DORA is associated with variable clinical presentation and prognosis. • DORA is a possible differential diagnosis in cats with ASD and obstruction to LA outflow.

Interaction of background Ca influx, sarcoplasmic reticulum threshold and heart failure in determining propensity for Ca waves in sheep heart.

Ventricular arrhythmias can cause death in heart failure (HF). A trigger is the occurrence of Ca waves which activate a Na -Ca exchange (NCX) current, leading to delayed after-depolarisations and triggered action potentials. Waves arise when sarcoplasmic reticulum (SR) Ca content reaches a threshold and are commonly induced experimentally by raising external Ca , although the mechanism by which this causes waves is unclear and was the focus of this study.

Evaluation of serum cardiac troponin-I concentrations for diagnosis of infective endocarditis in dogs.

Background: Infective endocarditis (IE) in dogs is associated with severe disease and a high case fatality rate but often presents with nonspecific clinical signs.

Hypothesis/objectives: Serum concentration of cardiac troponin-I (cTnI) is elevated in dogs with IE and can differentiate dogs with IE from dogs with other diseases with similar clinical features. Concentration of serum cTnI is negatively correlated with survival time in dogs with IE.

Clinical features and outcome of dogs and cats with bidirectional and continuous right-to-left shunting patent ductus arteriosus.

Background: Studies describing the clinical progression of animals with reverse patent ductus arteriosus (PDA) are lacking.

Objectives: To describe the signalment, presenting signs, echocardiographic features, and survival in a group of dogs and cats with bidirectional and continuous right-to-left PDA.

Animals: Forty-six client-owned animals included, comprising 43 dogs and 3 cats with bidirectional or continuous right-to-left PDA.

Association of diet with left ventricular wall thickness, troponin I and IGF-1 in cats with subclinical hypertrophic cardiomyopathy.

Background: Cats with subclinical hypertrophic cardiomyopathy (sHCM) have elevated serum insulin and serum amyloid A concentrations correlating with the degree of cardiac hypertrophy. Diet might affect these and other cardiac variables.

Objective: Evaluate the effect of a complete, balanced diet with restricted starch and supplemented with eicosapentaenoic acid + docosahexaenoic acid (EPA + DHA) on echocardiographic variables and cardiac biomarkers in cats with sHCM.

Associations among echocardiography, cardiac biomarkers, insulin metabolism, morphology, and inflammation in cats with asymptomatic hypertrophic cardiomyopathy.

Background: Insulin, insulin-like growth factor-1 (IGF-1), and inflammation possibly are involved in cats with asymptomatic hypertrophic cardiomyopathy (aHCM).

Objectives: To evaluate echocardiography, morphology, cardiac and inflammatory markers, insulin and IGF-1 in cats with aHCM.

Animals: Fifty-one client-owned cats with aHCM.

Effect of pimobendan on left atrial function in dogs with preclinical myxomatous mitral valve disease.

Background: Left atrial (LA) function is an important determinant of the left ventricular (LV) filling, playing a key role in maintaining optimal cardiac performance. Pimobendan is a phosphodiesterase III inhibitor with positive inotropic and vasodilator effects. The present study aims to investigate the effects of pimobendan on LA function in dogs with stage B2 myxomatous mitral valve disease (MMVD).

Temporal Development of Autonomic Dysfunction in Heart Failure: Effects of Age in an Ovine Rapid-pacing Model.

Heart failure (HF) is predominantly a disease of older adults and characterized by extensive sympatho-vagal imbalance leading to impaired reflex control of heart rate (HR). However, whether aging influences the development or extent of the autonomic imbalance in HF remains unclear. To address this, we used an ovine model of aging with tachypacing-induced HF to determine whether aging affects the chronotropic and inotropic responses to autonomic stimulation and reduction in heart rate variability (HRV) in HF.

Vitamin D status predicts 30 day mortality in hospitalised cats.

Vitamin D insufficiency, defined as low serum concentrations of the major circulating form of vitamin D, 25 hydroxyvitamin D (25(OH)D), has been associated with the development of numerous infectious, inflammatory, and neoplastic disorders in humans. In addition, vitamin D insufficiency has been found to be predictive of mortality for many disorders. However, interpretation of human studies is difficult since vitamin D status is influenced by many factors, including diet, season, latitude, and exposure to UV radiation.

Perturbed atrial calcium handling in an ovine model of heart failure: potential roles for reductions in the L-type calcium current.

Heart failure (HF) is commonly associated with reduced cardiac output and an increased risk of atrial arrhythmias particularly during β-adrenergic stimulation. The aim of the present study was to determine how HF alters systolic Ca(2+) and the response to β-adrenergic (β-AR) stimulation in atrial myocytes. HF was induced in sheep by ventricular tachypacing and changes in intracellular Ca(2+) concentration studied in single left atrial myocytes under voltage and current clamp conditions.

Diastolic spontaneous calcium release from the sarcoplasmic reticulum increases beat-to-beat variability of repolarization in canine ventricular myocytes after β-adrenergic stimulation.

Rationale: Spontaneous Ca(2+) release (SCR) from the sarcoplasmic reticulum can cause delayed afterdepolarizations and triggered activity, contributing to arrhythmogenesis during β-adrenergic stimulation. Excessive beat-to-beat variability of repolarization duration (BVR) is a proarrhythmic marker. Previous research has shown that BVR is increased during intense β-adrenergic stimulation, leading to SCR.