| Objective: To observe atrial and atrioventricular node electrophysiological changes induced by sinus node dysfunction(SND), To investigate autonomic nerve function changes after SND and the clinical significance by means of correlated parameters of heart rate turbulence(HRT).Methods: The model of rabbits with SND was established in 30 rabbits, Those rabbits were anesthetized and fixed on the table, the chest was opened through the right lateral line away 2 to 3 millimeters from the sternum, The sinoatrial node area of rabbits was damaged by cotton bud dipping 20% formaldehyde. And then we observed the changes of heart rate and cardiac rhythm; determined parameters of HRT; measured AERP,AVNERP and ERP-RA with S1S2 programmed electrical stimulation at before and after SND;observed the evocation of atrial fibrillation and gap phenomenon.Results: 1. 1h, 2h, 4h after SND compared with 0h after SND in S1S1300ms while 0h, 1h, 2h, 4h after SND compared with before SND in S1S1250ms and S1S1200ms, AERP was significantly shortened since 1h after SND and AVNERP was significantly prolonged since 2h after SND. 2.AERP adaptation to rate was normal before SND and in 0h after SND while inverted in 1h, 2h, 4h after SND; AVNERP adaptation to rate was normal before and after SND.3. Compared with before SND,the evocation of gap phenomenon was not significantly different before and after SND.4.Compared with before SND, the evocation of atrial fibrillation was significantly increased in 2h, 4h after SND.5. TO and TS were not significantly different before and after SND.Conclusion: 1.It is a reliable and feasible method to establish the model of SND by formaldehyde.2.Atrial electrical remodeling may induced since 1h after SND, displayed as the shorten of AERP and inverted of AERP adaptation to rate.3. The prolong of AVNERP may be observed and the evocation of atrial fibrillation may increased in 2h after SND, and it may illuminate that the disequilibrium of autonomic nerve is noticeable in 2h after SND. |
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