Laboratory of Veterinary Internal Medicine, School of Veterinary Medicine, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo 180-8602, Japan.
J Vet Med Sci. 2021 Dec 9;83(12):1918-1927. doi: 10.1292/jvms.21-0195. Epub 2021 Nov 4.
Pulmonary hypertension (PH) is a common comorbidity in dogs with myxomatous mitral valve disease (MMVD), and can induce various changes in the right heart, such as right ventricular (RV) hypertrophy, dilatation, and dysfunction. We hypothesized that RV function, not only systolic function but also diastolic function, could be worsened with PH progression. We aimed to compare RV systolic and diastolic function in dogs with MMVD. Twenty healthy dogs and sixty-eight dogs with MMVD were enrolled. Dogs with MMVD were classified into the probability of PH. Two-dimensional and Doppler echocardiographic indices for right heart and two-dimensional speckle tracking echocardiography indices were measured. The morphological indicators of the right heart were significantly higher only in the high probability of PH group. The RV strain, early-diastolic and systolic strain rates were significantly lower in the high probability of PH group than those in the low and intermediate probability of PH groups. Multivariate analysis showed that increased RV internal dimension normalized by body weight and RV myocardial performance index were significantly associated with the presence of right-sided congestive heart failure. Speckle tracking echocardiography-derived RV systolic and diastolic function were activated in the low and intermediate probability of PH groups. However, dogs with high probability of PH showed RV myocardial dysfunction and dilatation. Increased RV myocardial performance index and end-diastolic RV internal dimension normalized by body weight were significantly associated with the presence of right-sided congestive heart failure in dogs with MMVD.
肺动脉高压（PH）是黏液瘤性二尖瓣疾病（MMVD）犬的常见合并症，可引起右心的各种变化，如右心室（RV）肥厚、扩张和功能障碍。我们假设随着 PH 的进展，RV 功能（不仅是收缩功能，还包括舒张功能）可能会恶化。我们旨在比较 MMVD 犬的 RV 收缩和舒张功能。纳入了 20 只健康犬和 68 只 MMVD 犬。将 MMVD 犬分为 PH 可能性组。测量右心的二维和多普勒超声心动图指标以及二维斑点追踪超声心动图指标。仅在高 PH 可能性组中，右心的形态指标显著更高。高 PH 可能性组的 RV 应变、早期舒张和收缩应变率显著低于低和中 PH 可能性组。多变量分析显示，RV 内部尺寸标准化的体重和 RV 心肌性能指数增加与右侧充血性心力衰竭的存在显著相关。斑点追踪超声心动图衍生的 RV 收缩和舒张功能在低和中 PH 可能性组中被激活。然而，高 PH 可能性的犬显示 RV 心肌功能障碍和扩张。RV 心肌性能指数和体重标准化的 RV 舒张末期内部尺寸的增加与 MMVD 犬右侧充血性心力衰竭的存在显著相关。
