RX; Terumo, Tokyo, Japan). A standard thora- Mitral valve repair in dogs with MR has been

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2 Echocardiographic evaluation of mitral regurgitant volume after mitral valve repair in dogs Y Nakamura et al. months [16] after the surgery. RX; Terumo, Tokyo, Japan). A standard thora- Mitral valve repair in dogs with MR has been cotomy was performed at the left fourth or fifth shown to reduce heart size and improve clinical intercostal space. Heparin sodium (200 U/kg, in- signs [16]. However, the efficacy of mitral valve travenous; Novo-heparin; Mochida Pharmaceuti- repair should be based on a reduction of the vol- cal Co., Ltd., Tokyo, Japan) was administered. An ume of MR because other parameters such as arterial CPB cannula (6 8 Fr, Flexmate; Toyobo, heart size indexes on radiography and echocar- Shiga, Japan) was inserted into the carotid artery diography may not be a direct result of de- and a venous CPB cannula (8 12 Fr, Bio-Medi- creased MR. Determining the change in MR vol- cus DLP CPB cannula; Medtronic, Tokyo, Japan) ume may contribute to future improvements in was inserted into the jugular vein; and both were surgical technique (e.g. annuloplasty and place- secured to tourniquets and connected to the ment of artificial chordae techniques) as well as CPB circuit. Cardiac arrest was induced with car- aid in the prediction of long term outcome after dioplegia-adjusted potassium (20 meq/l; Mio- mitral valve repair. tector; Mochida, Tokyo, Japan) through a 5F aor- The aim of this study was to evaluate the outcome of mitral valve repair under cardiopulmonary bypass (CPB) in dogs by quantitating the mitral regurgitant volume, and to determine the efficacy of mitral valve repair as a treatment option for dogs with MR. Materials and Methods The study included dogs with naturally occurring MR that underwent mitral valve repair under CPB at Nihon University between December 2008 and October Exclusion criteria was the presence of aortic regurgitation by echocardiography. General anaesthesia was administered, and mitral valve repair was performed in the same manner for all the dogs, as previously described by Uechi [16]. Briefly, the dogs were Figure 1. Measurements for the mitral inflow volume. Velocity-time integral of the mitral inflow waveform in the left parasternal long-axis view, and cross-sectional area of the mitral annulus in the right parasternal short-axis view. oxygenated with 100% oxygen, followed by face mask induction with 5% isoflurane (Isoflurane for animal, Intervet Schering-Plough Animal Health, Ibaraki, Japan) and intubation with an endotracheal tube. Anaesthesia was maintained using 2 3% isoflurane with 100% oxygen at 1.5 L/min. During CPB, anaesthesia was maintained by constant rate infusion of fentanyl (0.4 µg/kg/min, intravenous; Fentanyl, Janssen Pharmaceutical K.K., Tokyo, Japan) and propofol (0.2 mg/kg/min, intravenous; rapinovet; Intervet Schering-Plough Animal Health, Ibaraki, Japan). CPB was provided using a heart-lung machine (Heart-lung machine; Terumo, Tokyo, Japan) with an extracorporeal circuit, oxygenator, and heat exchanger (Baby- Figure 2. Measurements for the aortic outflow volume. Velocity-time integral of the aortic outflow waveform in the left parasternal long-axis view, and cross-sectional area of the aortic annulus in the right parasternal short-axis view. Journal of Veterinary Cardiovascular Medicine (2017) 1, 2 9. ISSN: /@ 2017 Animal Circulation Society. All rights reserved. 3

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