Introduction/Objectives

In horses, persistent atrial dysfunction is a prognostic indicator of recurrence of atrial fibrillation (AF). The objective of this study was to quantify left atrial (LA) contractile function in Warmblood horses after successful cardioversion of AF to sinus rhythm, using standard two-dimensional echocardiography (2DE) and two-dimensional speckle tracking (2DST) analyses, and to provide proof-of-concept for use of 2DST to detect LA contractile dysfunction in horses.

Animals, materials, and methods

Nineteen Warmblood horses with AF and successful transvenous electrical cardioversion (TVEC) or medical cardioversion using quinidine sulfate (QS) were included. Echocardiography was performed at 24 hr, 72 hr, and 1–6 months after cardioversion. Conventional 2DE-derived indices of LA size and function and global longitudinal strain (S_L) and longitudinal strain rate (SR_L) during LA contractile function were measured to detect differences in LA size and function over time and between treatment modalities. The association between 2DE-derived indices and global S_L and SR_L, respectively, and the agreement of the variables to detect LA dysfunction were assessed.

Results

Global S_L and SR_L, as well as active LA fractional area change (FAC) identified cases with LA dysfunction after TVEC and QS cardioversion and proved useful to demonstrate LA functional recovery over time. Agreement between active LA FAC and S_L and SR_L, respectively, to diagnose atrial dysfunction was substantial to fair at 24 hr after cardioversion and decreased with time.

Conclusion

This study shows that 2DST is useful to quantify LA contractile dysfunction in horses after cardioversion of AF.

中文翻译：

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在房颤转换为窦性心律后，使用二维斑点跟踪超声心动图量化马的左心房收缩功能

介绍/目标

在马中，持续的心房功能障碍是心房颤动 (AF) 复发的预后指标。本研究的目的是使用标准的二维超声心动图 (2DE) 和二维斑点追踪 (2DST) 分析，在成功将 AF 复律为窦性心律后量化温血马的左心房 (LA) 收缩功能，并提供使用 2DST 检测马的 LA 收缩功能障碍的概念验证。

动物、材料和方法

包括 19 匹 AF 和成功的经静脉电复律 (TVEC) 或使用硫酸奎尼丁 (QS) 的医学复律的温血马。在复律后 24 小时、72 小时和 1-6 个月进行超声心动图检查。常规2DE衍生的LA的大小和功能和全球纵向应变（S的索引_大号）和纵向应变速率（SR_大号LA收缩功能期间）进行测定，以检测随时间和治疗模式之间的LA的大小和功能的差异。二维超声心动图派生指数和全球S之间的关联_大号和SR_大号，分别与变量的协议来检测LA功能障碍进行了评估。

结果

全球小号_大号和SR_大号，以及活性LA面积变化分数（FAC）鉴定例后TVEC和QS复律LA功能障碍和证明是有益的随着时间的推移表现出LA功能恢复。活性LA FAC和S之间的协议_大号和SR_大号，分别诊断心房功能障碍是相当大公平在复律后24小时，并随时间逐渐减少。

结论

该研究表明，2DST 可用于量化 AF 复律后马的 LA 收缩功能障碍。