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.

無徴候の6カ月齢のゴールデン・レトリーバーに収縮期駆出性心雑音が聴取された。大動脈は弁下部の隆起物と弁尖の癒合に伴う開放運動制限により狭窄しており，大動脈弁下部狭窄および弁性狭窄と診断した。大動脈弁口面積：0.20 cm²，流速：5.28 m/s，圧較差：111.7 mmHgと狭窄は重度であった。第39病日にバルーン弁形成術を実施した。術中に心室細動となったが，除細動により正常洞調律に復した。その後不整脈は認められず，入院3日での退院となった。術後の検査では弁口面積：1.02 cm²，流速：3.97 m/s，圧較差：63.1 mmHgと改善が見られ，経過は良好である。大動脈弁下部狭窄と弁性狭窄を合併している犬にもバルーン弁形成術は有効である可能性が示唆された。

僧帽弁閉鎖不全症と診断された7歳，雄のチワワに僧帽弁形成術 (mitral valve plasty; MVP)を行った。MVP前後の血流方向の変化を評価するために，超音波を用いたvector flow mappingを実施した。解析の結果，MVP前後で血流方向に明らかな変化は見られず，拡張早期に左室内に流入した血流は心尖部に向かったのち心室中隔に沿って流出路へと向かった。また，術前に左室内の中隔側と自由壁側に認められた渦は，術後には自由壁側で消失したが，中隔側に大きなものが残っていた。このように手術後により正常に近い血流となっていたことから，良好なMVPが行われていたことが血流解析の結果からも示唆された。

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.