Cardiovascular Division, Cardiac Arrhythmia Center, University of Minnesota, Minneapolis, Minnesota.
J Cardiovasc Electrophysiol. 2019 Feb;30(2):221-229. doi: 10.1111/jce.13780. Epub 2018 Nov 21.
Syncope triggered by swallowing is a well-known but uncommon condition that has been the focus of case reports but is otherwise largely unstudied. To better understand swallow syncope we examined heart rate (HR) and blood pressure (BP) changes during swallowing in clinically suspected swallow syncope patients and asymptomatic control subjects.
The study population comprised four individuals with a history suggesting swallow syncope (three men, 53 ± 14.9 years) and 15 (nine men, 46 ± 17.1 years, P = NS vs patients) asymptomatic volunteer control subjects. Studies in all individuals comprised noninvasive beat-to-beat HR and BP measurement during swallowing 150 mL of cold liquid while standing. Additional tests in swallow syncope patients included: active standing, Valsalva maneuver, carotid sinus massage (CSM), and head-up tilt (HUT).
Swallowing resulted in a greater decrease of both HR (-22 ± 22.1 vs -3 ± 11.7 beats/minute [bpm]; P = 0.045) and BP (-22 ± 17.4 vs - 2 ± 11.8; P = 0.036) in swallow syncope patients than in controls. Further, in swallow syncope patients the time to lowest HR and BP differed (9 ± 5.5 vs 19 ± 7.2 seconds; P = 0.02), suggesting that both cardioinhibitory (CI) and vasodepressor (VD) mechanisms are present but operate independently. Other autonomic studies were normal in swallow syncope patients except for CSM pause more than 3 seconds in two patients.
Swallow syncope is associated with transient and temporally independent CI and VD features, consistent with reflex syncope. Potentially, a swallowing test during autonomic evaluation may be useful to unmask relative magnitudes of CI and VD responses, thereby facilitating treatment strategy decisions.
吞咽引发的晕厥是一种众所周知但不常见的情况，已有病例报告对此进行了重点关注，但在其他方面研究甚少。为了更好地了解吞咽性晕厥，我们检查了临床疑似吞咽性晕厥患者和无症状对照受试者在吞咽过程中心率（HR）和血压（BP）的变化。
研究人群包括四名有吞咽性晕厥病史的个体（三名男性，53±14.9 岁）和 15 名（九名男性，46±17.1 岁，P=NS 与患者相比）无症状志愿者对照受试者。所有个体的研究均包括在站立时吞咽 150 毫升冷液体期间进行非侵入性逐搏 HR 和 BP 测量。吞咽性晕厥患者的附加测试包括：主动站立、瓦尔萨尔瓦动作、颈动脉窦按摩（CSM）和头高位倾斜（HUT）。
吞咽导致 HR（-22±22.1 与-3±11.7 次/分钟 [bpm]；P=0.045）和 BP（-22±17.4 与-2±11.8；P=0.036）较对照组显著下降。此外，在吞咽性晕厥患者中，最低 HR 和 BP 的时间不同（9±5.5 与 19±7.2 秒；P=0.02），提示存在心脏抑制（CI）和血管舒张（VD）两种机制，但独立作用。除了两名患者 CSM 暂停超过 3 秒外，吞咽性晕厥患者的其他自主神经研究均正常。
吞咽性晕厥与反射性晕厥一致，与短暂且时间上独立的 CI 和 VD 特征相关。在自主神经评估期间进行吞咽测试可能有助于揭示 CI 和 VD 反应的相对幅度，从而有助于治疗策略决策。
