McIntosh S J, Lawson J, Kenny R A
Department of Medicine/Geriatric Medicine, Royal Victoria Infirmary, Newcastle upon Tyne, United Kingdom.
Am J Med. 1993 Aug;95(2):203-8. doi: 10.1016/0002-9343(93)90261-m.
Carotid sinus syndrome (CSS) is frequently overlooked as a cause of syncope in the elderly. It is diagnosed when carotid sinus massage (CSM) produces asystole exceeding 3 seconds (cardioinhibitory CSS), a reduction in systolic blood pressure exceeding 50 mm Hg independent of heart rate slowing (vasodepressor CSS), or a combination of the two (mixed CSS). Most published data pertain to the cardioinhibitory subtype. The recent availability of noninvasive phasic blood pressure monitoring has allowed accurate routine assessment of the vasodepressor response to CSM. The aim of this study was to assess the clinical characteristics of vasodepressor, cardioinhibitory, and mixed CSS.
CSM was carried out on 132 consecutive patients over 65 years referred for investigation of dizziness, falls, or syncope. Massage was performed both supine and upright with continuous electrocardiographic and phasic blood pressure monitoring. Patients exhibiting greater than 1.5-second asystole were given 600 micrograms of intravenous atropine to abolish heart rate slowing and allow assessment of the pure vasodepressor response.
Carotid sinus hypersensitivity was documented in 64 patients (mean age 81 +/- 7 years, 31 male). The response was vasodepressor in 37%, cardioinhibitory in 29%, and mixed in 34%. Thirty-six patients had recurrent syncope, 17 presented with unexplained falls, and the remainder had dizziness alone. Symptoms had been present for a median of 24 months, and the median number of syncopal episodes was four. Twenty-five percent had sustained a fracture and, of these, 93% had not experienced a prodrome. Head movement precipitated symptoms in 47% and vagal stimuli in 73%. Episodes were unwitnessed in two thirds of patients. Twelve patients who presented with falls denied syncope but had witnessed loss of consciousness during CSM. Mean cardioinhibition was 5 +/- 2 seconds and mean vasodepression 61 +/- 9 mm Hg. The blood pressure nadir occurred rapidly at 18 +/- 3 seconds after massage, and baseline values were regained at 30 +/- 6 seconds. The clinical characteristics of patients with vasodepressor, cardioinhibitory, and mixed responses were similar.
CSS is an underdiagnosed cause of dizziness, falls, and syncope in the elderly. The vasodepressor form occurs more frequently than previously reported and has clinical characteristics similar to those of the cardioinhibitory and mixed subtypes. Elderly patients with this condition may deny syncope and present with recurrent unexplained falls. CSM, ideally with noninvasive phasic blood pressure monitoring, should be routinely performed in elderly patients with unexplained bradycardic or hypotensive symptoms.
颈动脉窦综合征（CSS）在老年人晕厥病因中常被忽视。当颈动脉窦按摩（CSM）导致心脏停搏超过3秒（心脏抑制型CSS）、收缩压下降超过50 mmHg且与心率减慢无关（血管减压型CSS）或两者兼而有之（混合型CSS）时，可作出诊断。大多数已发表的数据涉及心脏抑制型亚型。最近无创性相位血压监测的应用使得能够准确常规评估CSM的血管减压反应。本研究的目的是评估血管减压型、心脏抑制型和混合型CSS的临床特征。
对132例65岁以上因头晕、跌倒或晕厥前来检查的连续患者进行CSM。按摩在仰卧位和直立位进行，同时进行连续心电图和相位血压监测。出现超过1.5秒心脏停搏的患者静脉注射600微克阿托品以消除心率减慢，从而评估纯血管减压反应。
64例患者（平均年龄81±7岁，31例男性）记录到颈动脉窦过敏。反应为血管减压型的占37%，心脏抑制型的占29%，混合型的占34%。36例患者有反复晕厥，17例表现为不明原因跌倒，其余仅有头晕。症状出现的中位时间为24个月，晕厥发作的中位次数为4次。25%的患者发生过骨折，其中93%没有前驱症状。47%的患者头部运动可诱发症状，73%的患者迷走神经刺激可诱发症状。三分之二的患者发作时无人目睹。12例因跌倒就诊的患者否认晕厥，但在CSM期间有目击者看到其意识丧失。平均心脏抑制时间为5±2秒，平均血管减压幅度为61±9 mmHg。血压最低点在按摩后18±3秒迅速出现，30±6秒恢复到基线值。血管减压型、心脏抑制型和混合型反应患者的临床特征相似。
CSS是老年人头晕、跌倒和晕厥的一个诊断不足的病因。血管减压型比以前报道的更常见，其临床特征与心脏抑制型和混合型亚型相似。患有这种疾病的老年患者可能否认晕厥，表现为反复不明原因跌倒。对于有不明原因心动过缓或低血压症状的老年患者，理想情况下应常规进行CSM，最好同时进行无创性相位血压监测。
