OBJECTIVE To evaluate accuracy of quantification of right ventricle volume (RVV) by use of 3-D echocardiography (3DE) and ECG-gated multidetector CT (MDCT). ANIMALS 6 healthy hound-cross dogs. PROCEDURES ECG-gated MDCT and complete 3DE examinations were performed on each dog. Right ventricular end-diastolic volumes (EDVs), end-systolic volumes (ESVs), stroke volume (SV), and ejection fraction (EF) were measured for 3DE and MDCT data sets by use of software specific for RVV quantification. Correlation and level of agreement between methods were determined. Intraobserver and interobserver variability were assessed for 3DE. RESULTS No significant differences were detected between SV and EF obtained with MDCT and 3DE. Significant differences were detected between right ventricular EDV and ESV obtained with MDCT and 3DE. No significant difference in heart rate was detected between methods. The correlation between MDCT and 3DE was very good (r = 0.87) for EDV and ESV, moderate (r = 0.60) for EF, and poor (r = 0.31) for SV. Bland-Altman analysis revealed a systematic underestimation of RVV derived by use of 3DE, compared with the RVV derived by use of MDCT (mean bias, 15 and 10.3 mL for EDV and ESV, respectively). Intraobserver (EDV, 12%; ESV, 18%) and interobserver (EDV, 14%; ESV, 11%) variability were acceptable for 3DE. CONCLUSIONS AND CLINICAL RELEVANCE There was substantial variance for RVV measured by use of 3DE in healthy dogs and a significant underestimation of volumes, compared with results for MDCT, despite the fact there were no significant differences in SV and EF.

OBJECTIVE To investigate cardiac structural and functional changes by tissue Doppler imaging (TDI) and strain imaging in dogs with spontaneous type 1 diabetes mellitus. ANIMALS 30 client-owned dogs, of which 10 had normotensive type 1 diabetes mellitus and 20 were healthy. PROCEDURES All dogs underwent physical examination, laboratory analyses, standard echocardiography, and TDI. RESULTS On TDI and strain imaging, transmitral peak early diastolic velocity (E)-to-tissue Doppler–derived peak early diastolic velocity at basal segment (E') of septum ratio, E:lateral E’ ratio, and septal tissue Doppler–derived peak late diastolic velocity at basal segment (A') were significantly higher and the septal E':A’ ratio and lateral longitudinal strain were significantly lower for diabetic dogs than for control dogs. Furthermore, in diabetic dogs, serum glucose and fructosamine concentrations after a 12-hour period of food withholding were positively correlated with regional systolic functional variables (septal and lateral longitudinal strain) and left ventricular filling pressure indices (E:septal E’ and E:lateral E’ ratios) but were negatively correlated with diastolic functional variables (E:transmitral peak late diastolic velocity and septal and lateral E':A’ ratios). CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that myocardial function in diabetic dogs may be altered before the development of clinical heart-associated signs and that the change may be more readily detected by TDI and strain imaging than by conventional echocardiography. In addition, findings indicated that hyperglycemia could have detrimental effects on myocardial function, independent of hypertension, other cardiac diseases, and left ventricular hypertrophy, in dogs with type 1 diabetes.

OBJECTIVE To investigate mechanisms by which anti-inflammatory doses of orally administered intermediate-acting glucocorticoids (prednisone) could predispose dogs to progression of heart disease or congestive heart failure. ANIMALS 11 client-owned dogs with allergic dermatitis and 11 matched healthy control dogs. PROCEDURES Clinicopathologic, echocardiographic, and hemodynamic variables were measured. Dogs with allergic dermatitis then received prednisone (1 mg/kg, PO) once daily for 14 consecutive days beginning on day 0 (baseline), followed by a tapering and washout period; control dogs received no treatment. Measurements were repeated on days 7, 14, and 35. Linear mixed modeling was used to compare changes in variables across measurement points and between dog groups. RESULTS Prednisone administration caused no significant changes in serum sodium or potassium concentration, blood glucose concentration, or target echocardiographic variables. The change from baseline in systolic arterial blood pressure at day 7 was significantly greater in prednisone-treated dogs than in control dogs. Expected changes in hematologic and serum biochemical values with prednisone administration (neutrophilia, eosinopenia, isosthenuria, and high serum alkaline phosphatase and alanine aminotransferase activities) also occurred in the prednisone-treated dogs. CONCLUSIONS AND CLINICAL RELEVANCE Findings suggested that anti-inflammatory doses of orally administered glucocorticoids have the potential to adversely impact cardiac function in dogs by causing an increase in blood pressure and thus increased cardiac afterload.