B-mode and M-mode Ultrasonographic Evaluation of the Correlation between Diameter of Caudal Vena Cava and Right Heart Function in Dogs

• Main Authors: Yi-Ling Liu, 劉怡伶
• Other Authors: 鄭豐邦
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/22822651115977795115

碩士 === 國立中興大學 === 獸醫學系暨研究所 === 98 === The right heart is important to maintain hemodynamic stability through the pulmonary circulation, but its anatomically complex characteristic is difficult to describe by a simple geometric figure. Two-dimensional (B-mode) ultrasonographic detection of human inferior vena cava (IVC) has been widely used for assessing hydration status and diagnosing congestive right heart failure. However, the phasic blood flow from IVC to right atrium will influence the diameter of IVC. M-mode ultrasonography shows the time-motion characteristics of IVC, and identifies its physiologic size and pulsation. The aims of this study were to measure the diameter of caudal vena cava (dCVC) by B-mode and M-mode ultrasonography, and to evaluate its association with right heart function. The study population consisted of 26 Malteses, 12 Golden Retrievers, and 11 Labrador Retrievers aging from 1-6 years. The result showed that the dCVC was significantly different between Malteses (4.98 ± 0.72 mm) and Retrievers (11.75 ± 1.30 mm) (p < 0.05), and was highly correlated with body weight (r2 > 0.87). The CVC/aorta diameter ratio was irrelevant to body weight and to the breed (p > 0.05). The dCVC measured by B-mode and M-mode ultrasonography was highly correlated (r2 = 0.98), but the differences of M-mode dCVC were slightly more than B-mode (p > 0.05). The stroke volume (SV) and cardiac output (CO) of the right ventricle (RV) were correlated with dCVC (r2 = 0.45 vs. r2 = 0.52, p < 0.05). The dCVC of the dogs with right heart regurgitation (RH-R) were slightly larger than the dogs without RH-R (p > 0.05). Conclusively, CVC/aorta ratio seems to be independent from body weight, and the ratio could be used more conveniently in clinical examination. M-mode dCVC could be predictive for B-mode ultrasonography, however, the M-mode ultrasonography could even provide the exact assessment in clinical setting. Even though dCVC might not be a sensitive assessment of right heart function, it could still be applied to detect the RH-R and evaluate the RVSV and RVCO. Hence, dCVC measurement can be used alternatively for evaluating right heart function.