Background

Severe aortic stenosis (AoS) is considered a primary cause of syncope. However, other mechanisms may be present in these patients and accurate diagnosis can have important clinical implications. The aim of this study is to assess the different etiologies of syncope in patients with severe AoS and the impact on prognosis of attaining a certain or highly probable diagnosis for the syncope.

Methods

Out of a cohort of 331 patients with AoS and syncope, 61 had severe AoS and were included in the study. Main cause of syncope and adverse cardiac events were assessed.

Results

In 40 patients (65.6%), we reached a certain or highly probable diagnosis of the main cause of the syncope. AoS was considered the primary cause of the syncope in only 7 patients (17.5% of the patients with known etiology). Atrioventricular block (14 patients, 35.0%) and vasovagal syncope (6 patients, 15.0%) were the most frequently diagnosed causes. The presence of a known cause for syncope during the admission was not associated with a lower incidence of recurrence during follow-up (hazard ratio [HR] 0.69, 95% confidence interval [CI] 0.20-2.40). Syncope of unknown etiology was independently associated with greater mortality during 1-year follow-up (HR 5.4, 95% CI 1.3-21.6) and 3-year follow-up (HR 3.5, 95% CI 1.2-10.3).

Conclusions

In a high proportion of patients with severe AoS admitted for syncope, the valvulopathy was not the main cause of the syncope. Syncope in two-thirds of this population was caused by either bradyarrhythmia or reflex causes. Syncope of unknown cause was associated with increased short- and medium-term mortality, independently from treatment of the valve disease. An exhaustive work-up should be conducted to determine the main cause for syncope.

中文翻译：

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严重主动脉瓣狭窄患者的晕厥：不仅仅是阻塞问题

背景

严重主动脉瓣狭窄 (AoS) 被认为是晕厥的主要原因。然而，这些患者可能存在其他机制，准确的诊断可能具有重要的临床意义。本研究的目的是评估重度 AoS 患者晕厥的不同病因，以及对晕厥做出某种或高度可能的诊断对预后的影响。

方法

在 331 名 AoS 和晕厥患者的队列中，61 名患有严重的 AoS 并被纳入研究。评估了晕厥和不良心脏事件的主要原因。

结果

在 40 名患者 (65.6%) 中，我们对晕厥的主要原因做出了确定或高度可能的诊断。只有 7 名患者（17.5% 的已知病因患者）认为 AoS 是晕厥的主要原因。房室传导阻滞（14 例，35.0%）和血管迷走性晕厥（6 例，15.0%）是最常诊断的原因。入院期间存在已知晕厥原因与随访期间复发率较低无关（风险比 [HR] 0.69，95% 置信区间 [CI] 0.20-2.40）。病因不明的晕厥与 1 年随访（HR 5.4，95% CI 1.3-21.6）和 3 年随访（HR 3.5，95% CI 1.2-10.3）期间较高的死亡率独立相关。

结论

在大部分因晕厥而入院的严重 AoS 患者中，瓣膜病不是晕厥的主要原因。该人群中有三分之二的晕厥是由心动过缓或反射原因引起的。不明原因晕厥与短期和中期死亡率增加有关，与瓣膜疾病的治疗无关。应进行详尽的检查以确定晕厥的主要原因。