Background: The effects of pimobendan on left atrial pressure (LAP) in dogs with mitral valve disease (MR) have not been documented in a quantitative manner.Objective: The objective was to document and study the short-term effects of pimobendan on LAP and echocardiographic parameters in MR dogs.Animals: Eight healthy Beagle dogs weighing 10.0-14.7 kg (3 males and 5 females; aged 2 years) were used. Methods: Experimental, cross-over, and interventional study. Dogs with surgically induced MR received pimobendan at either 0.25 mg/kg or 0.50 mg/kg PO q12h for 7 days and then, after a 7-day wash-out period, the other dosage. LAP was measured for 30 minutes at baseline and again on days 1, 2, 4, and 7 of pimobendan administration.Results: Mean LAP was significantly decreased after the administration of 0.25 mg/kg (15.81 ± 5.44 mmHg to 12.67 ± 5.71 mmHg, P < .001) and 0.50 mg/kg (15.76 ± 5.45 mmHg to 10.77 ± 5.23 mmHg, P < .001). Also, the 0.50 mg/ kg group led to a significantly lower LAP (P < .01) compared with the 0.25 mg/kg group. Significant reduction was seen for the first time 4 days after the administration of 0.25 mg/kg and a day after the administration of 0.50 mg/kg.Conclusions and Clinical Importance: Pimobendan decreased LAP in a dose-dependent manner in dogs with acute MR caused by experimental chordal rupture. This study did not evaluate adverse effects of high-dose pimobendan, and additional studies in clinical patients are warranted.

Background: The effects of furosemide on left atrial pressure (LAP) in dogs with mitral regurgitation (MR) have not been documented in a quantitative manner and between different routes of administration.Objective: To document LAP and echocardiographic parameters in MR dogs administered furosemide IV or PO, in order to document changes in LAP after furosemide treatment.Animals: Five healthy Beagle dogs (3 males and 2 females; aged 2 years) were used. Methods: Experimental, cross-over, and interventional study. LAP was measured before the administration of furosemide, and 30 minutes, 1, 1.5, 2, 3, 4, 5, 6, 8, 12, and 24 hours after administration. Furosemide 1, 2, or 4 mg/kg IV, PO or placebo was administered.Results: LAP was significantly decreased with all administrations of furosemide but not after placebo (P o .05, respectively). The max reduction was observed 1 hour (1 mg/kg IV, 15.04 AE 7.02 mmHg), 3 hours (2, 4 mg/kg IV, 13.28 AE 8.01, 9.23 AE 4.92 mmHg), 4 hours (1 mg/kg PO, 14.68 AE 11.51 mmHg), and 5 hours (2, 4 mg/kg PO, 13.19 AE 10.52, 10.70 AE 7.69 mmHg). E wave and E/Ea were significantly decreased corresponding to the reduction of LAP after administration of 2 and 4 mg/kg (P o .05, respectively).Conclusions and Clinical Importance: LAP was decreased in proportion to the dosage of furosemide, which did not significantly differ between IV and PO of the same dosages. E wave and E/Ea might be useful for the treatment evaluation of furosemide.Key words: Radio telemetry system; Total circulating blood volume; Transmitral blood flow.M itral valve disease is the most common cardiac disease in dogs. As many as three quarters of all dogs with signs of congestive heart failure suffer from mitral regurgitation (MR) caused by myxomatous degeneration of the valve leaflets or the chordae tendineae.1,2 MR increases the left atrial pressure (LAP) which potentially results in left atrial dilation. Elevated LAP causes pulmonary edema that can lead to cough, dyspnea, and even death.3 Therefore, LAP needs to be reduced to avoid these clinical signs.Furosemide, a loop diuretic, has a strong diuretic effect and is commonly used for the treatment of pulmonary edema in patients with MR. 4 Furosemide reduces the total circulating blood volume, which in turn reduces the LAP or the left ventricular filling pressure, and leads to the clinical improvement of the patients. [5][6][7][8][9] There are several administration routes for furosemide, including IV, PO, SC, and IM. Pharmacokinetics of furosemide has been compared between IV and PO administration. However, the effects of furosemide on LAP in dogs with MR have not been well documented in a quantitative manner because there are some difficulties in measuring LAP directly. We have previously reported the 24-hour LAP profiles of and the effect of angiotensin-converting enzyme (ACE) inhibitors on experimentally induced MR dogs with a radio telemetry system. 10,11 The previous study has demonstrated that this system is useful for the evaluation of hemodynamic changes that occur...

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Improving cell viability and function are important for enhancing the clinical results of cell transplantation. The relationship between cell viability and shear stress remains unexplained, and sedimentation effects during the infusion process are important to the hepatocyte transplantation process. In the present study, the relationship between cell viability and shear stress in the presence of sedimentation effect was investigated using a microchannel simulating the cell transplantation process under several shear stress conditions. Horizontal and vertical syringe orientations were employed to investigate the sedimentation effect. The vertical syringe orientation resulted in lower viability loss than the horizontal orientation. In summary, removing a sedimentation effect is important to improving cell viability by preventing high shear stress.

An 11-month-old, 3 kg, female domestic shorthair cat was referred to evaluate cardiac structure and function. Echocardiography revealed the membrane dividing the left atrium into two chambers, a large defect in the lower part of the atrial septum, and turbulent blood flow from the distal left atrium into the right atrium. These findings suggested cor triatriatum sinister (CTS) with incomplete atrioventricular septal defect (AVSD). The cat was treated with medications for management of congestive heart failure. In the end, she died from right-sided heart failure 17 months after the initial presentation. At necropsy, a fibromuscular membrane with a round orifice in the left atrium and an ostium primum defect were confirmed, and the definitive diagnosis of CTS with incomplete AVSD was made. To our knowledge, this study presents the first case report of CTS with incomplete AVSD in a cat.