Introduction

Anterior mitral valve leaflet (AMVL) elongation is a recognised feature of hypertrophic cardiomyopathy (HCM). However, whether AMVL elongation precedes left ventricular hypertrophy in cats is currently unknown. The aim of this study was to explore the risk of developing an HCM phenotype in cats with an elongated AMVL.

Animals: Fifty-five apparently healthy cats with a normal baseline echocardiogram and a follow-up echocardiogram at >1 year. Materials and methods

This was a retrospective longitudinal study. Cats at the baseline were grouped based on whether or not they developed an HCM phenotype at follow-up. AMVL length and left atrial and left ventricular dimensions were measured from two-dimensional images.

Results

The median follow-up period of the study population was 5.4 years (25th and 75th quartile, 2.7–6.7). During this time, 17 cats (30.9%) developed an HCM phenotype. At the baseline, cats that subsequently developed an HCM phenotype had greater AMVL length (9.4 mm [25th and 75th quartile, 9.0–10.6] vs. 8.5 mm [25th and 75th quartile, 7.6–9.1], p < 0.0001) and maximal left ventricular wall thickness (4.5 mm [25th and 75th quartile, 4.1–4.7] vs. 4.0 mm [25th and 75th quartile, 3.7–4.6], p = 0.007) than those that did not. Multiple logistic regression analysis confirmed that both baseline variables were independent predictors for development of an HCM phenotype.

Conclusions

The AMVL length was greater in cats that subsequently developed left ventricular hypertrophy. Further studies investigating the clinical application of AMVL in the natural history of feline HCM are warranted.

中文翻译：

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肥厚型心肌病猫二尖瓣前叶长度

介绍

二尖瓣前叶 (AMVL) 延长是肥厚型心肌病 (HCM) 的公认特征。然而，目前尚不清楚 AMVL 延长是否先于猫的左心室肥厚。本研究的目的是探讨 AMVL 延长的猫发生 HCM 表型的风险。

动物：55 只表面健康的猫，基线超声心动图正常，随访超声心动图超过 1 年。材料和方法

这是一项回顾性纵向研究。基线时的猫根据它们在随访时是否出现 HCM 表型进行分组。AMVL 长度和左心房和左心室尺寸是从二维图像测量的。

结果

研究人群的中位随访期为 5.4 年（第 25 和第 75 个四分位数，2.7-6.7）。在此期间，17 只猫 (30.9%) 出现了 HCM 表型。在基线，随后发展为 HCM 表型的猫具有更大的 AMVL 长度（9.4 毫米 [第 25 和第 75 个四分位数，9.0-10.6] vs. 8.5 毫米 [第 25 个和第 75 个四分位数，7.6-9.1]，p < 0.0001）和最大左侧心室壁厚度（4.5 毫米 [第 25 和第 75 个四分位数，4.1-4.7] vs. 4.0 毫米 [第 25 和第 75 个四分位数，3.7-4.6]，p = 0.007）比那些没有。多元逻辑回归分析证实，两个基线变量都是 HCM 表型发展的独立预测因子。

结论

随后发展为左心室肥厚的猫的 AMVL 长度更长。进一步研究 AMVL 在猫 HCM 自然病程中的临床应用是有必要的。