Wang Mei-lian, Zhang Ying, Fan Miao, Guo Ya-jun, Ren Wei-dong, Luo En-jie
Department of Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, No, 92 Beier Road, Shenyang 110001, Heping District, China.
Cardiovasc Ultrasound. 2014 Jun 20;12:21. doi: 10.1186/1476-7120-12-21.
We previously reported the use of a catheter system to damage the tricuspid valve and create infectious endocarditis (IE) in an animal model. The current study aims to create a faint IE model suitable for antibiotic prophylaxis using a low bacterial inoculum. We also aim to explore a way to quantitatively assess valvular impairment and to predict the success of the IE models during catheterization.
Ninety rabbits were assigned to two groups according to the density of bacteria inoculated (1 × 10(5) CFU for Group A and 1 × 10(4) CFU for Group B). A catheter system consisting of a polyethylene catheter and a guide wire were used to damage the valve. The catheter system was passed through the rabbits' tricuspid valves under echocardiographic guidance. A pressure transducer was used to assess right atrial pressure (P(RA)) before and just after valvular damage to calculate the pressure alterations (ΔP(RA)). The animals in group A and B were divided into 3 subgroups according to the ΔP(RA) (0-5 mmHg for Groups A1 and B1; 5-10 mmHg for Groups A2 and B2; 10-15 mmHg for Groups A3 and B3). Staphylococcus aureus (ATCC 29213) inoculation was performed 24 hr after cardiac catheterization.
Faint IE was confirmed in 20%, 93.3%, 26.7%, 6.7%, 20%, and 33.3% of the rabbits in Groups A1, A2, A3, B1, B2, and B3, respectively. There was no difference in the LV/RV ratio and VTR of the No-IE, faint-IE, and severe IE animals. Faint IE rabbits had a larger ΔPRA than No-IE rabbits (7.81 ± 1.21 vs. 2.48 ± 1.0, P < 0.01, for Group A; 7.60 ± 1.32 vs. 2.98 ± 1.08, P < 0.01, for Group B). The ΔPRA of severe IE and faint IE rabbits was significantly different (13.11 ± 1.31 vs. 7.81 ± 1.21, P < 0.01, for Group A; 12.73 ± 1.44 vs.7.60 ± 1.32, P < 0.01, for Group B).
ΔP(RA) could be used to assess valvular impairment. Controlling the value of ΔP(RA) during catheterization and inoculating of an appropriate dose of bacteria was associated with a successful IE model.
我们之前报道了在动物模型中使用导管系统损伤三尖瓣并引发感染性心内膜炎（IE）。当前研究旨在使用低细菌接种量创建一种适用于抗生素预防的轻度IE模型。我们还旨在探索一种定量评估瓣膜损伤的方法，并预测导管插入过程中IE模型的成功情况。
根据接种细菌的密度将90只兔子分为两组（A组接种1×10⁵CFU，B组接种1×10⁴CFU）。使用由聚乙烯导管和导丝组成的导管系统损伤瓣膜。在超声心动图引导下，将导管系统穿过兔子的三尖瓣。使用压力传感器在瓣膜损伤前后评估右心房压力（P(RA)），以计算压力变化（ΔP(RA)）。根据ΔP(RA)将A组和B组动物分为3个亚组（A1组和B1组为0 - 5 mmHg；A2组和B2组为5 - 10 mmHg；A3组和B3组为10 - 15 mmHg）。心脏导管插入术后24小时进行金黄色葡萄球菌（ATCC 29213）接种。
A1组、A2组、A3组、B1组、B2组和B3组兔子中分别有20%、93.3%、26.7%、6.7%、20%和33.3%确诊为轻度IE。无IE、轻度IE和重度IE动物的左心室/右心室比值和瓣膜反流率无差异。轻度IE兔子的ΔPRA大于无IE兔子（A组：7.81±1.21 vs. 2.48±1.0，P < 0.01；B组：7.60±1.32 vs. 2.98±1.08，P < 0.01）。重度IE和轻度IE兔子的ΔPRA有显著差异（A组：13.11±1.31 vs. 7.81±1.21，P < 0.01；B组：12.73±1.44 vs. 7.60±1.32，P < 0.01）。
ΔP(RA)可用于评估瓣膜损伤。在导管插入过程中控制ΔP(RA)的值并接种适当剂量细菌与成功的IE模型相关。
