Brignole M, Gianfranchi L, Menozzi C, Bottoni N, Bollini R, Lolli G, Oddone D, Gaggioli G
Department of Cardiology, Hospital Riuniti, Lavagna, Italy.
Pacing Clin Electrophysiol. 1994 Nov;17(11 Pt 2):1889-94. doi: 10.1111/j.1540-8159.1994.tb03769.x.
Atrial fibrillation is a relative contraindication to atrial synchronous pacing because of the risk of the tracking of rapid atrial rhythms by the pacemaker. In this study, we describe the clinical results of an AV synchronous rate responsive pacemaker with an original algorithm, which is able to sense pathological increments in atrial rate and automatically to switch into a non-AV synchronous mode of pacing. This pacemaker was implanted in 12 patients who had undergone radiofrequency ablation of the AV junction in order to cure severely symptomatic, drug refractory, paroxysmal atrial fibrillation. In an acute, intrapatient comparison between the standard AV synchronous mode and the automatic switching mode, ventricular tracking of atrial fibrillation occurred in 35% and 4% of total beats at rest and in 24% and 2% of total beats during exercise, respectively (P < 0.001). During 5 +/- 4 months of follow-up, no further tachyarrhythmia related symptoms occurred. In conclusion, the standard DDDR mode is unable to eliminate ventricular tracking of atrial fibrillation, thus undermining the efficacy of AV junction ablation therapy. The automatic switching mode eliminates this adverse effect of dual chamber pacing.
由于起搏器有追踪快速房性心律的风险，心房颤动是心房同步起搏的相对禁忌证。在本研究中，我们描述了一种具有原创算法的房室同步频率应答式起搏器的临床结果，该算法能够感知心房率的病理性增加并自动切换到非房室同步起搏模式。将此起搏器植入12例接受房室结射频消融术以治疗严重症状性、药物难治性阵发性心房颤动的患者。在标准房室同步模式与自动切换模式的急性患者内比较中，静息时房颤心室跟踪分别占总心搏数的35%和4%，运动时分别占总心搏数的24%和2%（P<0.001）。在5±4个月的随访期间，未再出现与快速心律失常相关的症状。总之，标准的DDDR模式无法消除房颤的心室跟踪，从而削弱了房室结消融治疗的疗效。自动切换模式消除了双腔起搏的这一不良影响。
