Echocardiographic evaluation of mitral regurgitant volume after mitral valve repair in dogs

抄録

Objectives. The efficacy of mitral valve repair, an established treatment for mitral regurgitation (MR) in dogs, is unclear. We evaluated the outcome of mitral valve repair in dogs by quantitating the mitral regurgitant volume.

Methods. Dogs that underwent mitral valve repair for naturally occurring MR between December 2008 and October 2012 were included. Stroke mitral regurgitant volume and minute mitral regurgitant volume were calculated by echocardiography preoperatively and at 1 and 3 months postoperatively. Severity of MR was classified by mitral regurgitant fraction (trivial, <30%; mild, 30–49%; moderate, 50–79%; and severe, ≥80%).

Results. A total of 65 dogs were included (body weight, 3.75 [1.55–16.45] kg; age, 8 [5–12] years). The postoperative mitral inflow volume was significantly lower, whereas the aortic outflow volume was significantly higher than preoperative values. Thus, the stroke mitral regurgitant volume and the minute mitral regurgitant volume significantly decreased. Additionally, the postoperative mitral regurgitant fraction was significantly lower than the preoperative value. Severe MR was detected in 38 dogs preoperatively, but in none postoperatively.

Clinical Significance. Mitral valve repair in dogs decreased MR volume, leading to hemodynamic improvement. Quantitating the MR volume proved to be an effective method for evaluating the efficacy of mitral valve repair.