山羊心房颤动进展过程中心房电图形态的演变

Changes of atrial electrograms configuration associated with the development of atrial fibrillation in goats.

目的利用山羊模型研究心房颤动(简称房颤)在由阵发性向持续性转变过程中,心房/肺静脉外膜电图形态的演变。方法在山羊的左房(LA)游离壁外膜和左上肺静脉(LSPV)根部缝合电极片,利用自制的房颤刺激器于体外发放50Hz的刺激,刺激左房,刺激时程1s,每次间隔2s,诱发出自发维持时间超过24h的持续性房颤。将心房/肺静脉外膜电图形态分为单电位(SP)、双电位(DP)和碎裂电位(FP)。分析在基础状态下和房颤维持不同时间时各电位在所有激动中所占比例和动态变化。结果在窦性心律时LA和LSPV全为SP,随着房颤持续时间的延长,两部位的SP比例逐渐减少,DP和FP的比例逐渐增加。房颤刚开始和持续24h后SP的比例在LA分别为94.2%±5.0%和68.4%±6.0%(P<0.01),在LSPV则分别为74.2%±3.3%和40.1%±7.3%(P<0.01)。在房颤自发持续24h后,LA各种形态的电位交替出现,而LSPV可见连续的反复快速激动。结论心房和肺静脉外膜电图的碎裂程度增加,以及肺静脉出现连续的反复快速激动与房颤的持续有关。

Objective To investigate the atrial electrograms configuration changes in the development of atrial fibrillation （AF）. Methods Ten female goats were instrumented with epicardial electrodes patches on the left atrium （LA） free wall and the root of left superior pulmonary vein （LSPV）. AF was induced and maintained by a home-made stimulator with frequency of 50 Hz, duration of 1 second and 2 seconds intermission. The epicardial atrial electrograms were classified as single potential （ SP）, double potential （DP） and fragmented potential （FP）. The percentage of different potentials at LA and LSPV was calculated in the process of AF getting stable. Results Eight goats finished the study. Persistent AF （〉24h） was induced in all the 8 goats within 6 to 16 days. Only SP could be find at LA and LSPV in sinus rhythm. In the first episode of induced AF and after induced AF lasted for 24 hours, the percentage of SP at LA was 94. 2% ± 5.0% and 68. 4% ± 6.0% respectively （ P 〈 0.01 ）, it was 74.2% ± 3.3% and 40.1% ± 7.3% respectively （ P 〈 0.01 ） at LSPV. During persistent AF, different atrial electrograms transited at LA and at LSPV continuous repetitive rapid activations （RRAs） occurred. Conclusions The increase of fractionated atrial electrograms at atrium/pulmonary vein, and occurrence of RRAs at pulmonary vein are associated with the perpetuation of AF.