The aim of the present study was to investigate the therapeutic action of pimobendan in rats with monocrotaline (MCT)-induced pulmonary hypertension (PH). Twenty-four 12-week-old male Sprague-Dawley rats were injected with MCT or saline solution. They then received either no further treatment (MCT group) or oral pimobendan immediately (early-phase treatment) or 4 weeks (late-phase treatment) after injection. At day 42 after MCT injection, echocardiography was performed and then right ventricular systolic pressure was measured via a cardiac catheter. There were no differences in hemodynamic variables between the pimobendan-treated groups and the saline group, regardless of the timing of therapy. It was suggested that acrocinesis was caused by excess pimobendan in the early phase, whereas in the late phase during PH progression, pimobendan preserved diastolic function without an increase in HR.

This study was aimed at to compare fatty acid (FA) concentrations in the ventricular myocardium between dogs with tachycardia-induced cardiomyopathy (TICM) caused by electrical pacing and control dogs. Ventricular myocardia obtained from seven TICM dogs and five healthy dogs were used. After myocardial samples obtained from the right ventricle (RV), interventricular septum (IVS), and left ventricle (LV) were homogenized separately, FAs were extracted and methylated. The methylated FAs were then purified and analyzed using gas chromatography. Their concentrations (μg/mL) were determined with a dedicated analytical system. Although the concentrations of 13 FA types in the RV were significantly higher in the TICM group than in the control group, only lignoceric acid (C24 : 0) concentrations were significantly lower in the former. The concentrations of 18 FA types in the IVS were significantly higher in the TICM group than in the control group. Moreover, the concentrations of 18 FA types in the LV were also significantly higher in the TICM group than in the control group, whereas only lignoceric acid (C24 : 0) concentrations were significantly lower in the former. The FA concentrations in the TICM dogs differed from those in the healthy dogs. Further study of FA concentrations in TICM dogs is warranted to elucidate myocardial energy metabolism in spontaneous dilated cardiomyopathy and disorders associated with this disease.

A 13-year-old miniature pinscher with mitral valve insufficiency was planned to perform mitral valve plasty (MVP). However, pancreatitis was complicated before surgery. Four days after medical therapy, MVP with cardiopulmonary bypass (CPB) was performed, because clinical symptom calmed down. Although subclinical pancreatic cellular injury occurred postoperatively, the case recovered satisfactory by an intensive care and the recurrence of pancreatitis have not been found during 14 months after surgery. Pancreatitis is common in dogs with mitral valve insufficiency. These cases could undergo MVP with CPB safety by a higher level of monitoring (clinical symptom, serum pancreatic enzyme, WBC, plate, CRP, and coagulation system) and intensive care in perioperative period.