IMPLANTABLE DEVICE FOR THE TREATMENT OF ATRIAL FIBRILLATION
Cooper JM,Katcher MS,Orlov MV
NEJM,2002,346(26) :2062-68
Atrial fibrillation is a common arrhythmia
Common symptoms:
palpitations
Dyspnea
fatigue
Associated complications:
Stroke
heart failure
death
Cooper JM ,et al.NEJM,2002,346(26) :2062-68
Common Approaches
Rate control plus anticoagulation
Rhythm control with antiarrythmic medications
Pacemaker and defibrillator
Cooper JM ,et al.NEJM,2002,346(26) :2062-68
Ventricular pacing
during artrial fibrillation
Symptomatic bradycardia -----permanent pacemakers
The atrioventricular node is bomdarded with electrial impulses
The factors influences on Ventricular rate
intrinsic conduction-system disease
takeing rate-controlling pharmacologic agents
with high a vagal tone
Cooper JM ,et al.NEJM,2002,346(26) :2062-68
Ablation of atrioventricular node plus implantation of pacemaker(1)
decreases the incidence of palpitations ,dyspnea,et al
increases exercise tolerance
elminates rate-controlling medications
improves the cardiovascular hemodynamic
Cooper JM ,et al.NEJM,2002,346(26) :2062-68
Ablation of atrioventricular node plus implantation of pacemaker
No effect on the fibrillation in the atria
No effect on the associated risk of thromboembolism
Cooper JM ,et al.NEJM,2002,346(26) :2062-68
适应证
症状严重的、药物无效或不能耐受药物治疗的慢性房颤和房扑患者
一般均有不同类型的基础病
Prevention of atrial fibrillation with atrial pacing
The mechanism of atrial pacing
Allows coordinated contraction of the chambers
Lowers average atrial pressure
Deacreases any stretch-related changes
Prevents pauses and reduces the risk of the atrial fibrillation associated with increased vagal tone and braycardia
Supress ectopic atrial beats
The Mode Selection Trial
Number of patients: More than 2000 patients with the SSS
Two groups: ventricular pacemaker,dual-chamber pacemaker
The primary end points: mortality,stroke
Result: no difference with respect to the primary end point;50% decrease in the likehood of a first episode of atrial fibillation and a reduction in kisk of progression to chronic atrial fibillation with dual-chamber pacing
Press release of NASP,Natick,Mass,May,2001
Alternative single-site and dual-site atrial paceng
房间传导阻滞（Interartrial Conduction Block）
一般人群房间传导阻滞发生1%，缓—速综合征患者发生率32%
诊断标准：右房与左房间传导超过100ms
体表心电图：
P波增宽
P波时限≥120ms
Ⅰ导联P波常有明显切迹，切迹间双峰间距＞0.04
Ⅱ、Ⅲ 导联P波双向，先负后正
Synchronized atrial activation
Usual single-site of atrial pacing:
interatrial septum
coronary sinus
Bachmann’bundle
……
Dual-site of atrial pcing
the right atrial appendage
interatrial septum
Dual-atrial pacing
the right atrial appendage
coronary sinus
Patients in whom the the atrial lead was placed at Bachmann’budle or on the interatrial septum had a lower incidence of parxymal and chronic atrial fibrillation than those in whom the lead was posisioned in the traditional right atrial appendage.
Bailin SJ,et al.JCE,2001;142:1047-55
双房同步起搏
双心房＋右心室起搏，是三腔人工心脏起搏器的一种。
用于防治与房间传导阻滞有关的某些快速性房性心律失常
冠状窦起搏的最佳位电多选择在冠状窦中部
双房同步起搏方式
单腔起搏器：仅有房间传导阻滞及快速房性心律失常，选用双极AAT方式
双腔DDD起搏器：同时合并缓慢性心律失常或房室传导阻滞，选用DDD(R）方式
Chorus 6234或7034（ela corp）：
AAT(房间水平)+DDD（房室间水平）
Overdrive atrial pacing
The mechanism of overdrive atrial pacing
The atrial pacing predominate over the intrinsic atrial activity to reduce the initiation of atrial fibrillation
Supresses prematrue atrial beats
Influnces the pattern of atrial depolarization
Lowers the incidence of atrial arrhythmia
Decrease the number of days during which atrial fibrillation occurred
High-frequency pacing
and electrical cardioversion
Antitachycardia device(1)
The Metrix Atrioverter,InControl
The Jewel AF device,Medtronic
The GEM AT Ⅲ,Medtronic
Antitachycardia device(2)
The device was progremmed to detect artrial fibillation,and adminster a shock to restore sinus rythem
To deliver rapid atrial pacing to treat atrial arrhythmias
The over efficacy of thr device in teminating atrial fibrillation was 90%,1/3 episodes requiring more than one shock
Safty:no instence of ventricular proarrythmia
The GEM AT Ⅲ,Medtronic
The shocks for atrial fibrillation can be activeed by the patient
To be programmed to occur automatically in the early morning while the patent is sleep
To ensure that the shock is delivered within 24 hours after the onset of atrial fibrillation
Conclution and fulture
The ideal patient population for this invasive antiarrhythmic strategy has not been defined
25% patients who receive an implantable defibrillator for ventricular arrhythmias also have paroxymal artrial fibrillation