摘要目的 观察经心外膜射频消融犬右肺静脉脂肪垫、下腔静脉脂肪垫及心脏第3脂肪垫对藜芦定诱发的Bezold-Jarisch反射(BJR)及相关的血流动力学指标的影响,并探讨其临床意义.方法 30只杂种犬麻醉后经右侧开胸,随机分为对照组(不消融)、消融组(经心外膜消融上述3个脂肪垫).经左心室导管弹丸式推注藜芦定15μg/ks,比较两组推药前后心率、动脉收缩压、动脉舒张压、平均动脉压、左心室收缩压、左心室舒张末压、左心室压最大上升及下降速率的变化.结果 推注藜芦定前两组各项指标差异无统计学意义(P>0.05),推注藜芦定后消融组心率的下降显著低于对照组[(22.9±8.5)次/min vs(93.3±18.4)次/min,P<0.01)],但动脉压、左心室压、左心室雎最大上升及下降速率的变化与对照组相比差异无统计学意义(P>0.05).结论 经心外膜射频消融犬上述3个脂肪垫能明显消弱藜芦定诱发的BJR的心率抑制成分,但不能消弱BJR的血管抑制成分.此方法对防治心脏抑制型以及混合型血管迷走性晕厥可能有效,但对血管抑制型血管迷走性晕厥可能无效.

abstractsObjectives To evaluate the effects of radiofrequency catheter ablation (RFCA) on the RPV fat pad (FP),the IVC-LA FP and the SVC-AO FP during the Bezold-Jarisch reflex (BJR) induced by ve ratridine in dogs. Methods Thirty dogs were randomly divided into the control group which received no abla tion, and the ablation group which received epicardial ablation of the three FPs. Veratridine was injected into the left ventricle in bolus doses of 15 μg/kg through a catheter to induce the BJR. Heart rate (HR), systolic arterial pressure (SAP),diastolic arterial pressure (DAP),mean arterial pressure (MAP),left ventricular sys tolic pressure (LVSP), left ventricular diastolic pressure (LVDP), left ventricular peak systolic velocity (+dp/dt_(max)) and peak diastolic velocity (-dp/dt_(max)) were measured before and after veratridine injec tion. Results Prior to injection of veratridine, there were no significant differences in HR, SAP, DAP, MAP, LVSP, LVEDP and ± dp/dt_(max) between the two groups (P>0. 05). After injection of veratridine, the maximum decrement of HR in the ablation group was significantly lower than that in the control group[ (22. 9 ±8. 5)bpm vs(93. 3 ± 18. 4) bpm(P < 0. 01)). However, there were no differences in the maximum decrement of SAP, DAP,MAP,LVSP,LVEDP and ±dp/dt_(max) between the two groups(P >0.05). Conclusions RFCA of the RPV,IVC-LA and SVC-AO FPs significantly attenuated veratridine-mediated cardiac vagal component of the BJR. However, RFCA did not affect veratridine-mediated vasodepressor component of the BJR. This method may be useful in preventing cardioinhibitory VVS but not in preventing vasodepressor VVS.