William R. Pritchard Veterinary Medical Teaching Hospital, University of California, Davis, CA 95616, USA.
William R. Pritchard Veterinary Medical Teaching Hospital, Department of Medicine and Epidemiology, University of California, Davis, CA 95616, USA.
J Vet Cardiol. 2020 Jun;29:1-10. doi: 10.1016/j.jvc.2020.02.004. Epub 2020 Mar 31.
Quantitative measurements are commonly implemented to objectively evaluate heart size in dogs. However, recent studies suggest that the phase of cardiac cycle can impact vertebral heart score, thereby potentially influencing clinical management. This study used fluoroscopy to assess the impact of the cardiac cycle on quantitative cardiovascular measurements in healthy dogs of various breeds.
ANIMALS, MATERIALS, AND METHODS: This was a prospective study. Multiple cardiac and respiratory cycles were recorded fluoroscopically. Peak inspiratory end-systole and end-diastole frames were captured from 49 dogs in right lateral recumbency. Vertebral heart score (VHS), cardiothoracic ratio (CTR), vertebral left atrial size (VLAS), and caudal vena cava diameter ratio (CVCDR) measurements were performed. Mean cardiac measurements were compared between cardiac cycle phases, and the impact of body condition score (BCS), weight, thoracic conformation, sex, and age was evaluated.
Cardiac cycle had a significant impact on VHS (mean difference: 0.36 ± 0.14 vertebral units between systole and diastole; p < 0.001) and CTR (mean difference: 2.2 ± 1.2% between systole and diastole; p < 0.001). Cardiac cycle had no significant impact on VLAS or CVCDR. Increasing BCS significantly increased variation between systole and diastole in CTR measurements (p = 0.024).
The cardiac cycle has a significant effect on VHS and CTR but does not impact VLAS or CVCDR. These findings should be taken into consideration during clinical use of these measurements, especially if a patient is being monitored for cardiac changes over time via serial radiographs.
定量测量常用于客观评估犬的心脏大小。然而，最近的研究表明，心动周期的阶段会影响心脏横径与胸高比，从而可能影响临床管理。本研究使用透视技术评估心动周期对不同品种健康犬的心血管定量测量的影响。
动物、材料和方法：这是一项前瞻性研究。透视下记录多个心动周期和呼吸周期。在右侧卧位下从 49 只犬中捕获吸气末收缩期和舒张期的峰值帧。进行心脏横径（VHS）、心胸比（CTR）、左心房大小（VLAS）和腔静脉直径比（CVCDR）的测量。比较心动周期相位之间的平均心脏测量值，并评估体况评分（BCS）、体重、胸廓形状、性别和年龄的影响。
心动周期对 VHS（收缩期和舒张期之间的平均差异：0.36 ± 0.14 个椎体单位；p < 0.001）和 CTR（收缩期和舒张期之间的平均差异：2.2 ± 1.2%；p < 0.001）有显著影响。心动周期对 VLAS 或 CVCDR 无显著影响。BCS 增加显著增加了 CTR 测量中收缩期和舒张期之间的差异（p = 0.024）。
心动周期对 VHS 和 CTR 有显著影响，但对 VLAS 或 CVCDR 没有影响。在临床使用这些测量值时，应考虑到这些发现，特别是如果患者通过连续 X 光片监测随时间的心脏变化。
