Blanc J J, Genet L, Mansourati J, Forneiro I, Corbel C, Pennec Y, Mottier D
Service de Cardiologie, Hôpital Augustin Morvan, Brest.
Presse Med. 1990 May 5;19(18):857-9.
The cause of brief syncopes is discovered in only two-thirds of the cases at most. The purpose of this study was to quantify the value of the head-up tilt test in patients whose syncope remained "causeless" after a "conventional" investigation. Forty-nine patients entered the study on the following criteria: at least one syncope, no conduction disturbances or normal electrophysiological study, physiological response to carotid sinus massage, absence of postural hypotension and assessable tilt test. The head-up tilt test was performed under blood pressure and electrocardiographic monitoring in three stages: dorsal decubitus during 20 min, 60 degrees tilting during 20 min and, if nothing happened, isoprenaline injection. The test was positive (i.e. produced syncope or at least lipothymia) in 12 patients (24.5 per cent). In all cases the loss of consciousness was associated with a deep fall in blood pressure, but prolonged ventricular pause never occurred (2 patients had bradycardia at about 30 beats/min). The head-up tilt test is a non-invasive examination which in one-quarter of the cases provides a diagnosis of vasovagal syncope when no other diagnosis could be made; it reproduces the syncope, which is rarely done by other investigations, and it deserves to be include in the evaluation of unexplained syncopes.
短暂晕厥的病因最多仅在三分之二的病例中被发现。本研究的目的是量化头高位倾斜试验对于那些在“常规”检查后晕厥仍“原因不明”的患者的价值。49名患者根据以下标准进入研究：至少有一次晕厥，无传导障碍或电生理检查正常，对颈动脉窦按摩有生理反应，无体位性低血压且倾斜试验可评估。头高位倾斜试验在血压和心电图监测下分三个阶段进行：平卧位20分钟，倾斜60度20分钟，如果没有反应则注射异丙肾上腺素。该试验在12名患者（24.5%）中呈阳性（即诱发晕厥或至少晕厥前状态）。在所有病例中，意识丧失均与血压大幅下降相关，但从未发生过长时间心室停搏（2例患者有心动过缓，约30次/分钟）。头高位倾斜试验是一种非侵入性检查，在四分之一的病例中，当无法做出其他诊断时可诊断为血管迷走性晕厥；它能重现晕厥，而这很少能通过其他检查做到，它值得纳入不明原因晕厥的评估中。
