Nakamura K, Kawamoto S, Osuga T, Morita T, Sasaki N, Morishita K, Ohta H, Takiguchi M
Veterinary Teaching Hospital, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan.
Laboratory of Veterinary Internal Medicine, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan.
J Vet Intern Med. 2017 Mar;31(2):316-325. doi: 10.1111/jvim.14660. Epub 2017 Feb 1.
Decreased function of the left atrium (LA) is a useful prognostic indicator in dogs with myxomatous mitral valve disease (MMVD). In humans, LA strain is a novel severity indicator of mitral regurgitation, but its clinical utility in dogs has not been confirmed.
To examine whether LA strain as evaluated with speckle-tracking echocardiography is associated with MMVD stage in dogs.
Fifty-two client-owned dogs with MMVD.
Cross-sectional study. Dogs were classified as stage B1, B2, C, or D, according to the American College of Veterinary Internal Medicine consensus. Physical examination findings and echocardiographic variables were compared among the groups. To assess the comparative accuracy of echocardiographic variables in identifying dogs with the presence or history congestive heart failure (CHF), receiver operating characteristic curves and multivariate logistic analysis were used.
There were no significant differences in parameters of LA strain between B1 and B2 groups. However, LA longitudinal strain during atrial contraction (ε ) (median, 19.1%; interquartile range, 15.3-24.3% in B1, 19.6%; 14.1-21.4% in B2, 6.2%; 3.18-11.2% in C/D) and during ventricular systole (ε ) (32.7%; 28.9-39.2% in B1, 35.6%; 31.7-41.9% in B2, 23.6%; 16.9-26.1% in C/D) were significantly lower in stages C/D than in stages B1 and B2. In multivariate logistic regression analysis, ε and peak early diastolic mitral inflow velocity were identified as independent indicators of stage C/D.
ε was the best predictor of the presence or history of CHF. Further studies are needed to determine the clinical implications of these findings for treatment decisions and prognosis determination.
左心房（LA）功能降低是黏液瘤性二尖瓣疾病（MMVD）犬的一项有用的预后指标。在人类中，左心房应变是二尖瓣反流的一种新型严重程度指标，但其在犬类中的临床应用尚未得到证实。
研究斑点追踪超声心动图评估的左心房应变是否与犬的MMVD分期相关。
52只患有MMVD的客户自养犬。
横断面研究。根据美国兽医内科学会的共识，将犬分为B1、B2、C或D期。比较各组的体格检查结果和超声心动图变量。为评估超声心动图变量在识别有充血性心力衰竭（CHF）存在或病史的犬中的比较准确性，使用了受试者操作特征曲线和多变量逻辑分析。
B1组和B2组之间左心房应变参数无显著差异。然而，心房收缩期（ε）（中位数，19.1%；四分位间距，B1组为15.3 - 24.3%，B2组为19.6%；14.1 - 21.4%，C/D组为6.2%；3.18 - 11.2%）和心室收缩期（ε）（B1组为32.7%；28.9 - 39.2%，B2组为35.6%；31.7 - 41.9%，C/D组为23.6%；16.9 - 26.1%）的左心房纵向应变在C/D期显著低于B1期和B2期。在多变量逻辑回归分析中，ε和舒张早期二尖瓣血流峰值速度被确定为C/D期的独立指标。
ε是CHF存在或病史的最佳预测指标。需要进一步研究以确定这些发现对治疗决策和预后判定的临床意义。
