Interventricular inflow time difference (IVID), which is defined as the time interval between the opening of the mitral valve and the opening of the tricuspid valve, hold prognostic value in human patients with heart failure. Few reports regarding IVID are available in dogs. Ninety dogs with myxomatous mitral valve disease (MMVD) and 47 dogs without heart disease. Dogs with MMVD received unstandardized therapy based on the stage of disease. This was a prospective cohort study. Dogs were classified into two groups based on IVID: tricuspid opening preceding mitral opening (TOP) and mitral opening preceding tricuspid opening (MOP). The potential influence of the MOP group at enrollment on the primary outcome (cardiac-related death) was determined by Kaplan–Meier analysis. Almost all dogs without heart disease (97.9%) were classified in the TOP group. Twenty-nine dogs (32.2%) were classified in the MOP group. Left heart size, transmitral early diastolic inflow velocity, and right ventricular Tei index were significantly greater in the MOP group compared to those in the TOP group. Cardiac-related death were observed in 34 dogs (40.5%). The dogs in the MOP group at initial examination had shorter survival times than those in the TOP group (586 days vs. >1,831 days; 95% confidence interval, 237–714 days vs. 1,037 days to >1,831 days; P<0.001). Interventricular inflow time difference is potentially useful for prognostic assessments in dogs with MMVD. Further prospective studies that quantify the repeatability and influence of therapy on IVID are needed.

中文翻译：

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双脉冲多普勒超声心动图评估患有粘液瘤二尖瓣疾病的犬的室间流入时间差

室间流入时间差（IVID）定义为二尖瓣打开与三尖瓣打开之间的时间间隔，对心力衰竭患者具有预后价值。关于狗的 IVID 的报道很少。 90 只狗患有粘液性二尖瓣疾病 (MMVD)，47 只狗没有心脏病。患有 MMVD 的狗根据疾病阶段接受非标准化治疗。这是一项前瞻性队列研究。根据 IVID 将狗分为两组：三尖瓣开口先于二尖瓣开口（TOP）和二尖瓣开口先于三尖瓣开口（MOP）。通过 Kaplan-Meier 分析确定了入组时 MOP 组对主要结局（心脏相关死亡）的潜在影响。几乎所有没有心脏病的狗（97.9%）都被归入 TOP 组。二十九只狗（32.2%）被归为 MOP 组。 MOP 组的左心大小、二尖瓣舒张早期流入速度和右心室 Tei 指数显着大于 TOP 组。 34 只狗（40.5%）观察到与心脏相关的死亡。 MOP 组的狗在初次检查时比 TOP 组的存活时间短（586 天 vs. >1,831 天；95% 置信区间，237–714 天 vs. 1,037 天至 >1,831 天；P<0.001） 。室间流入时间差对于 MMVD 犬的预后评估可能有用。需要进一步的前瞻性研究来量化治疗的可重复性和对 IVID 的影响。