Brignole M, Menozzi C
Section of Arrhythmology, Ospedali Riuniti, Lavagna, Italy.
Pacing Clin Electrophysiol. 1997 Mar;20(3 Pt 2):795-800. doi: 10.1111/j.1540-8159.1997.tb03906.x.
The recording of spontaneous episodes of bradycardiac neurocardiogenic syncope (NCS) has shown that: a prolonged ventricular asystole seems necessary to cause syncope; asystole is preceded by other bradyarrhythmias in the vast majority of cases; some warning symptoms precede the loss of consciousness in most cases; conventional dual-chamber pacing is efficacious both in patients with a positive response to carotid sinus massage (CSM) and eyeball compression test (EBC) and in those with a positive response to tilt-testing (TT). CSM, EBC, and TT are established tools for diagnosing NCS, when the recording of spontaneous syncope is lacking. When combined together, they are probably able to correctly identify most patients affected by NCS. Nevertheless, whether the type of reflex induced by the cardiovascular reflexivity maneuvers correlates with that of the spontaneous syncope is largely unknown. Our knowledge suggests that the correlation may be unsatisfactory, owing to the following: the variability of the mechanism of spontaneous syncope from patient to patient and also, in the same patient, from one episode to another; the discordance of the type of response when 2 or 3 tests are positive in the same patient, the response being more frequently asystolic with CSM and EBC and more frequently vasodepressor with TT: the different timing between hypotension induced by CSM (in which it follows the bradycardia) and that induced by TT (in which it usually precedes the bradycardia) and the uncertainty about the timing of hypotension during the spontaneous syncope; the good reproducibility of the spontaneous event by CSM and EBC, but not by TT, when cardiac asystole is the manifestation of NCS; and the fairly high rate of false-positive results of cardiovascular reflexivity maneuvers. Hypotension is the main reason for the failure of pacemaker therapy in all the forms of neurocardiogenic syncope (NCS), whether diagnosed by CSM, EBC, or TT. Thus, the need arises to correctly identify the magnitude of the hypotensive reflexes of spontaneous events.
缓慢性神经心源性晕厥（NCS）自发发作的记录表明：长时间心室停搏似乎是导致晕厥的必要条件；在绝大多数情况下，停搏之前会出现其他缓慢性心律失常；大多数情况下，意识丧失之前会出现一些预警症状；传统双腔起搏对颈动脉窦按摩（CSM）和眼球压迫试验（EBC）呈阳性反应的患者以及对倾斜试验（TT）呈阳性反应的患者均有效。当缺乏自发晕厥记录时，CSM、EBC和TT是诊断NCS的既定工具。当联合使用时，它们可能能够正确识别大多数NCS患者。然而，心血管反射性操作诱发的反射类型与自发晕厥的反射类型是否相关，很大程度上尚不清楚。我们的认识表明，这种相关性可能并不理想，原因如下：患者之间以及同一患者不同发作之间自发晕厥机制的变异性；同一患者2项或3项检查呈阳性时反应类型的不一致，CSM和EBC时反应更常为停搏性，TT时更常为血管减压性；CSM诱发的低血压（其发生在心动过缓之后）与TT诱发的低血压（其通常发生在心动过缓之前）之间的不同时间关系以及自发晕厥期间低血压时间的不确定性；当心脏停搏是NCS的表现时，CSM和EBC对自发事件具有良好的可重复性，但TT则不然；以及心血管反射性操作的假阳性结果发生率相当高。低血压是所有形式神经心源性晕厥（NCS）起搏器治疗失败的主要原因，无论NCS是通过CSM、EBC还是TT诊断的。因此，有必要正确识别自发事件低血压反射的程度。
