自主神经节丛消融对窦房结及房室结功能的急性期影响

目的探讨神经节丛(GP)消融对窦房结(SAN)及房室结(AVN)功能的影响。方法 7条犬开胸并在左、右心房及肺静脉缝置多极电极导管以备记录及刺激,对左侧及右侧GP分别进行消融,消融前后分别测定静息心率、SAN及AVN功能,SAN功能包括测定6个不同水平起搏周长(380,350,330,300,280及250 ms)时SAN恢复时间(SNRT)以及校正的SNRT(cSNRT);AVN功能包括AH间期(H is束电图记录的房室结传导时间)、递增起搏时出现文氏房室传导阻滞时起搏周长、出现2∶1房室传导阻滞时起搏周长、右房短阵超速起搏诱发心房颤动(简称房颤)时的平均心室率。结果 GP消融后窦性心率无显著改变,长起搏周长时SNRT及cSNRT无显著变化,而短起搏周长时则显著减少(P0.05)。各起搏周长下AH间期、出现文氏房室传导阻滞及2∶1房室传导阻滞时的起搏周长、房颤时平均心室率在GP消融前后均无显著变化。结论 GP消融在较短起搏周长情况下增强了SAN功能,但对AVN功能无明显影响,可能与GP消融时同时破坏了副交感及交感神经成分有关。

Acute effects of ganglionated plexi ablation on sinoatrial nodal and atrioventricular nodal functions

Objective To investigate the effects of ganglionated plexi（GP） ablation on the sinoatrial nodal （SAN） and atrioventricular nodal （AVN） functions. Methods In seven open-chest dogs, multiple electrode catheters were sutured at both atria and pulmonary veins for recording and pacing. Left and fight GP was ablated separately. Measurement of resting heart rate, SAN and AVN function was performed before and after GP ablation. The SAN function was evaluated by measure- ments of sinus node recovery time （SNRT） and corrected sinus node recovery time （cSNRT） during rapid pacing from the distal pair of RA catheter at 6 levels of decremental pacing cycle length （CL,ms） ： 380, 350, 330, 300, 280 and 250. The AVN function was evaluated by measurements of （1）AH interval at incremental right atrium（RA） pacing;（2）the pacing CL at which Wenckebaeh atriovcntricular block（AVB） occurred during incremental pacing （ 10 ms steps） ;（3）the pacing CL at which 2：1 AV block occurred and （4）the average ventricu]ar rate when atrial fibrillation（AF） was induced by burst pacing at the RA. Results The sinus rate did not significantly change after GP ablations. The SNRT,cSNRT did not show significant changes at long pacing CLs, but significantly decreased at shorter CLs after GP ablations. The AH interval at different pacing CLs, the Wenckebach AVB CL, 2：1 AVB CL or the ventricular rate during AF were not significantly altered by GP ablations. Conclusions GP ablation enhances SAN function only at short pacing CLs and does not change AVN function. These results may be partially related to destroying both parasympathetic and sympathetic elements in the GP by ablation.