Abstract: Abstract：usually results in severe mitral regurgitation as well as marked dilatation of the atria and ventricles. As compensation progresses in the hearts of dogs with tendon rupture，it can manifest as reverse cardiac remodelling， whereby the originally dilated heart becomes smaller or even returns to normal. A 10⁃year⁃old brown poodle came to the hospital with significant exercise intolerance. Echocardiography revealed a ruptured mitral tendon cable with significant systolic regurgitation and marked left atrial and ventricle dilatation. Reexamination of the affected dog（at 3⁃ and 9⁃months post⁃diagnosis）revealed a gradual improvement in the degree of cardiac dilatation to normal size， consistent with cardiac reverse remodelling features. The affected dog had a favourable prognosis and showed a significant decrease in the frequency of exercise intolerance. Cases of cardiac reverse remodelling are uncommon in clinical practice. The authors report the long⁃term echocardiographic follow⁃up and diagnosis of the affected dog in this case in order to provide diagnostic ideas and references for the clinical diagnosis and treatment of this type of reverse remodelling in MMVD dogs with rupture of chordae tendineae.

Key words: Dog, Rupture of chordae tendineae, Myxomatous mitral valve disease, Reverse remodelling, Echocardiography

摘要： 二尖瓣腱索断裂是犬退行性瓣膜疾病（Myxomatous mitral valve disease，MMVD）的一 种常见并发症，通常会导致严重的二尖瓣返流以及心房心室明显扩张。少数患犬心脏随着代 偿的进展，会表现为反向心脏重塑，即原本扩张的心脏会变小甚至恢复至正常程度以及功能 的部分恢复。一只10岁棕色贵宾犬因运动不耐受明显而就诊，超声心动图发现二尖瓣腱索断 裂且伴有收缩期明显返流，左侧心房心室扩张明显。对患犬进行复查（距离确诊第3个月和第 9个月），发现心脏扩张程度逐渐改善至正常大小，符合心脏反重塑特征。该患犬预后良好，且 出现运动不耐受的频率下降明显。心脏反重塑案例在临床上并不常见，该文将该案例患犬长 期的超声心动图跟踪和诊治进行报道，以期对MMVD腱索断裂患犬反向重塑这一类型的临床 诊疗提供诊断思路与参考。

关键词: 犬, 腱索断裂, 退行性瓣膜疾病, 反重塑, 超声心动图