不同次数心室颤动后肿瘤坏死因子α和脑钠肽的变化与除颤阈值的相关性

摘要

目的 探讨犬单次短时间心室颤动(SDVF)和多次SDVFs后体内肿瘤坏死因子α(TNF-α)及脑钠肽(BNP)的变化及其与除颤阈值(DFT)的关系.方法 将144道(12×12,间距2 mm)自制电极片缝至比格犬(n=7)左室前侧壁.用于心外膜刺激和电生理标测.通过心外膜电极行30次快速脉冲(30 Hz)刺激诱发心室颤动(VF).经颈内静脉置入除颤电极,每次VF持续20 s后给予除颤,用能量递增、递减方法测定DFT.分别于基础状态下,开胸后30 min,第一次SDVF后5 min和多次SDVFs后留取动脉血.ELISA法测定血浆TNF-α及BNP的浓度.评估VF后TNF-α和BNP短时间内的变化,以及与DFT的关系.结果 基础状态与开胸后TNF-α和BNP浓度无差异.与基础状态相比,第一次SDVF后血中BNP(78±12.2μg/L vs 90±4.3μg/L,P=0.031)及TNF-α(547±104 ng/L vs 661±151 ng/L,P=0.036)浓度显著降低.多次SDVFs(3.43±0.73次)后,BNP及TNF-α水平有升高趋势,但与基础状态、单次SDVF后相比均无差异.DFT前血浆BNP水平与DFI"呈正相关(r=0.76,P=0.046).结论 单次SDVF后,血浆TNF-α及BNP浓度降低,多次SDVFs后两者浓度无明显变化.DFT前BNP水平与DFT呈正相关,提示心功能受损可能导致DFT升高.%Objective To investigate the alteration of tumor necrosis factor α(TNF-α) & type B natriuretic peptide (BNP) following a single and multi episodes of short duration ventricular fibrillation ( SDVF), and test the relationship between BNP, TNF-α and defibrillation threshold (DFT) in canine. Methods A custom epicardial electrode plaque which contains 144 ( 12 × 12, 2 mm spacing) unipolar electrodes was sutured on the left ventricular epicardium of 7 dogs'hearts. 30 times 30 Hz burst stimuli were given to induce ventricular fibrillation(VF) through the electrode in the plaque.A catheter with the cathode in the right ventricle apex and the anode in the superior vena cava was inserted for defibrillation. The DFT was determined by an up-down algorithm after VF lasted for 20 s. Blood samples were taken from the femoral artery at baseline, after open-chest, at 5min following a single SDVF (20 s), and after multi episodes of SDVFs. The blood concantrations of BNP and TNF-α were measured by ELISA. The relationships among BNP, TNF-α and DFT were evaluated. Results There was no significant difference between baseline and after open-chest in the concantration of BNP and TNF-α. Compared to baseline, BNP (78 ± 12.2 μg/L vs 90 ±4.3 μg/L, P =0.031 ) and TNF-α (547 ± 104 ng/L vs 661 ± 151 ng/L, P=0.036) significantly decreased after the first episode of SDVF. Compared with a single SDVF,BNP and TNF-α did no significantly change following multi episodes of SDVFs ( 3.43 ± 0.73 times). BNP had the positive correlation with DFT ( r = 0.76, P = 0.046 ).Conclusion BNP and TNF-α decrease after a single SDVF, but there is no significant increase following multi episodes of SDVFs. BNP has the positive correlation with DFT, which suggests that impaired cardiac function could cause the increase of DFT.