动态心房超速起搏治疗阵发性心房颤动

目的：评价动态心房超速起搏（dynamic atrial overdrive,DAO)方式治疗阵发性心房颤动的疗效。方法：3例均为女性，58－69岁，均为病态窦房结综合征合并阵发性心房颤动患者，植入Pacesetter公司Trilogy DR DAO 2364L型双腔起搏器。随机单盲将患者分为A组：DAO on和B组：DAO off；4个月后交换，即改为A组DAO off及B组DAO on再4个月，随访8－12个月。随访内容包括症状、抗心律失常药物增减及用程控仪观察自动模式转换（auto mode switch,AMS)的次数。结果：1）症状：3例心悸、胸闷症状无论在DAO off或on时均有好转。2）AMS：A组1例在DAO on及off各4个月的随访中，AMS分别为1次或0次，后继续off 4个月，AMS仍为0次，随继续关闭DAO。程控结果显示99％为心房起搏。该患者植入起搏器前后均未服用过抗心律失常药物。A组另1例在DAO on时AMS为764次，off时AMS为6232次，on较off则AMS发生率下降88％。该患者一直服用莫雷西嗪和肠溶阿司匹林。B组患者BAO off时AMS为16441次，on时AMSo 8081次，on较off时AMS下降51％。该患者因无明显心房颤动引起的症状而在DAO on期间自行停服抗心律失常药物。结论：动态心房超速起搏方式具有一定的预防阵发性心房颤动的作用。

Application of DDD Pacemaker with Dynamic Atrial Overdrive System in Paroxysmal atrial Fibrillation

Objective: To evaluate the effectiveness of DDD pacemaker with dynamic atrial overdrive (DAO) system in treatment of paroxysmal atrial fibrillation. Methods: Three female patients, 58-69 years old, with sick sinus syndrome complicated by paroxysmal atrial fibrillation were implanted with DDD pacemaker, Trilogy DR + DAO2364L which has the function of DAO. The patients were divided into two groups randomly. Group A (DAO function was switched on for 4 months) and group B (DAO function was switched off for 4 months) , while the two groups were crossed over for another 4 months. Symptom, the dosage of antiarrhythmia drug and the frequency of auto mode switch (AMS) were followed up. Results: Two patients were divided into group A while one patient in group B. Symptom: palpitation, chest distress were relieved after pacemaker implanted no matter DAO on or off. AMS in one patient of group A, without any antiarrhythmia drug taken, were 1 and 0 respectively during 4 months of DAO on and off. We went on turning off DAO for another 4 months and found that AMS was still 0. So we continued on switching the DAO off. Programmer showed atrial pacing during the follow up was 99%. Another patient in group A persisted in taking the same dose of moricizine and aspirin during DAO on and off. Programmer showed that AMS were 764 and 6232 respectively during DAO on and off (decreased 88% compared with DAO off). Patient in group B stopped taking antiarrhythmia drug during DAO on since no symptom, while AMS were 16441 (DAO off) versus 8081(DAO on) respectively. The frequency of AMS decrease 51% compared with DAO off. Conclusion: DDD pacemaker with DAO mode may have some effect on preventing the occurrence of the paroxysmal atrial fibrillaiton.