Introduction/objectives

Quantitative evaluation of the morphology of the mitral valve annulus (MVA) in dogs with myxomatous mitral valve disease (MMVD) may improve the techniques of mitral valve plasty. This study aimed to compare the MVA morphology on echocardiography in normal dogs and dogs with MMVD and to compare the echocardiographic and intraoperative measurements of the MVA in dogs with MMVD.

Animals, materials and methods

The study population comprised 59 healthy dogs (control group) and 371 dogs with MMVD (MMVD group). The anterior-posterior diameter and transversal diameter (TD) of the MVA and the aortic annulus diameter were measured by echocardiography to calculate the mitral valve flattening ratio, mitral annulus area (MAA), mitral annulus circumference (MAC), contraction ratio of the MAA and aortic annulus area. In the MMVD group, the mitral annulus diameter (MAD) was macroscopically measured during mitral valve plasty. Areas and lengths were divided by the body surface area (BSA) and √BSA, respectively, for comparative analyses.

Results

The systolic and diastolic anterior-posterior diameter/√BSA, transversal diameter/√BSA, MAA/BSA converted to a natural logarithm (Ln(MAA/BSA)), and MAC/√BSA was significantly higher in the MMVD group than the control group, whereas flattening ratio values and contraction ratio of the MAA was significantly lower. Neither the aortic annulus diameter /√BSA nor the Ln(aortic annulus area/BSA) significantly differed between groups. In the MMVD group, diastolic MAC/√BSA and MAA/BSA correlated significantly with the MAD/√BSA.

Conclusions

The MVA is larger and rounder in dogs with MMVD than controls. Two-dimensional echocardiographic measures of MAA and MAC correlate well with intraoperative measures of MAD.

中文翻译：

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与粘液瘤退行性二尖瓣疾病相关的犬二尖瓣环畸形和扩大的超声心动图评估

简介/目标

对患有粘液瘤二尖瓣疾病 (MMVD) 的犬的二尖瓣环 (MVA) 形态进行定量评估可能会改进二尖瓣成形术的技术。本研究旨在比较正常犬和患有 MMVD 犬的超声心动图上的 MVA 形态，并比较患有 MMVD 犬的 MVA 的超声心动图和术中测量值。

动物、材料和方法

研究人群包括 59 只健康狗（对照组）和 371 只患有 MMVD 的狗（MMVD 组）。超声心动图测量MVA前后径、横径（TD）和主动脉瓣环直径，计算二尖瓣压扁率、二尖瓣环面积（MAA）、二尖瓣环周长（MAC）、MAA收缩率和主动脉环区。在 MMVD 组中，在二尖瓣成形术期间肉眼测量二尖瓣环直径 (MAD)。面积和长度分别除以体表面积（BSA）和√BSA，用于比较分析。

结果

MMVD组收缩舒张前后径/√BSA、横径/√BSA、MAA/BSA换算为自然对数(Ln(MAA/BSA))、MAC/√BSA均显着高于对照组组，而 MAA 的扁平率值和收缩率显着降低。主动脉环直径/√BSA 和 Ln（主动脉环面积/BSA）在组间均无显着差异。在 MMVD 组中，舒张期 MAC/√BSA 和 MAA/BSA 与 MAD/√BSA 显着相关。

结论

与对照组相比，患有 MMVD 的狗的 MVA 更大更圆。MAA 和 MAC 的二维超声心动图测量与 MAD 的术中测量密切相关。