Kanjwal Khalil, Karabin Beverly, Kanjwal Yousuf, Grubb Blair P
Electrophysiology Section, Division of Cardiology, Department of Medicine, The University of Toledo Medical Center, Toledo, OH 43614, USA.
J Interv Card Electrophysiol. 2010 Jan;27(1):69-73. doi: 10.1007/s10840-009-9452-1. Epub 2009 Nov 25.
In many patients with recurrent neurocardiogenic syncope (NCS), a significant fall in blood pressure precedes any appreciable decline in heart rate. Closed-loop pacing (CLS) employs a sensing system that measures myocardial contractility, thereby providing a potential way to detect the onset of NCS at a much earlier point in time than that provided by standard pacing systems.
Patients were included in the study if they suffered from recurrent NCS and met all of the following criteria: (1) They had suffered at least two syncopal episodes in the preceding 6 months. (2) Patients were refractory to (or intolerant of) all conventional, non-pharmacological, or pharmacological treatments. (3) They had evidence of asystole (>10 s) or severe bradycardia (heart rate <30 bpm) on implantable loop recorder or during head-up tilt test (HUTT).
Thirty five patients meeting the above criterion received 44 devices. Twelve patients received a standard unit (with rate drop or rate hysterisis response) and 32 patients received a CLS unit (Cylos, Biotronik). The pacemaker implantation was termed successful if there was no recurrence of syncope, if the syncope burden decreased by > or =50%, if only presyncope occurred, or if the syncope occurred but with significant warning symptoms. Thirty-five patients, 29 females and six males, age 41 +/- 11, with refractory NCS underwent pacemaker implantation. Mean follow-up was 9 +/- 3 months. Out of 32 patients who received CLS, nine had a conventional pacemaker implanted in the past. Recurrence (59% vs 83%), reduction in syncope burden and pacemaker success (84% vs 25%, P = 0.002), and occurrence prodrome/warning signs (40% vs 16%) were much better in the closed-loop group.
These preliminary observations suggest that dual-chamber CLS pacing may be promising therapy for refractory NCS. Further randomized trials will be needed to better determine the role of this therapy in refractory NCS.
在许多复发性神经心源性晕厥（NCS）患者中，血压显著下降先于心率出现任何明显下降。闭环起搏（CLS）采用一种测量心肌收缩力的传感系统，因此提供了一种比标准起搏系统更早检测NCS发作的潜在方法。
如果患者患有复发性NCS且符合以下所有标准，则纳入本研究：（1）在过去6个月内至少发生过两次晕厥发作。（2）患者对所有传统、非药物或药物治疗无效（或不耐受）。（3）在植入式循环记录仪或头高位倾斜试验（HUTT）期间有心脏停搏（>10秒）或严重心动过缓（心率<30次/分钟）的证据。
35名符合上述标准的患者接受了44台设备。12名患者接受了标准装置（具有心率下降或心率滞后反应），32名患者接受了CLS装置（Cylos，百多力公司）。如果没有晕厥复发、晕厥负担降低≥50%、仅发生前驱晕厥或晕厥发生但伴有明显预警症状，则起搏器植入被称为成功。35例难治性NCS患者（29例女性和6例男性，年龄41±11岁）接受了起搏器植入。平均随访时间为9±3个月。在接受CLS的32例患者中，9例过去曾植入传统起搏器。闭环组的复发率（59%对83%）、晕厥负担减轻情况和起搏器成功率（84%对25%，P=0.002）以及前驱症状/预警信号的发生率（40%对16%）均明显更好。
这些初步观察结果表明，双腔CLS起搏可能是难治性NCS的一种有前景的治疗方法。需要进一步的随机试验来更好地确定这种治疗方法在难治性NCS中的作用。
