Abstract Aims Recent studies have shown that in more than half of apparently unexplained sudden cardiac arrests (SCA), a specific aetiology can be unmasked by a careful evaluation. The characteristics and the extent to which such cases undergo a systematic thorough investigation in real-life practice are unknown. Methods and results Data were analysed from an ongoing study, collecting all cases of out-of-hospital cardiac arrest in Paris area. Investigations performed during the index hospitalization or planned after discharge were gathered to evaluate the completeness of assessment of unexplained SCA. Between 2011 and 2016, among the 18 622 out-of-hospital cardiac arrests, 717 survivors (at hospital discharge) fulfilled the definition of cardiac SCA. Of those, 88 (12.3%) remained unexplained after electrocardiogram, echocardiography, and coronary angiography. Cardiac magnetic resonance imaging yielded the diagnosis in 25 (3.5%) cases, other investigations accounted for 14 (2.4%) additional diagnoses, and 49 (6.8%) patients were labelled as idiopathic ventricular fibrillation (IVF) (48.7 ± 15 years, 69.4% male). Among those labelled IVF, only 8 (16.3%) cases benefited from a complete workup (including pharmacological testing). Younger patients [odds ratio (OR) 6.00, 95% confidence interval (CI) 1.80–22.26] and those admitted to university centres (OR 3.60, 95% CI 1.12–12.45) were more thoroughly investigated. Genetic testing and family screening were initiated in only 9 (18.4%) and 12 (24.5%) cases, respectively. Conclusion Our findings suggest that complete investigations are carried out in a very low proportion of unexplained SCA. Standardized, systematic approaches need to be implemented to ensure that opportunities for specific therapies and preventive strategies (including relatives) are not missed.

中文翻译：

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真实世界中不明原因心脏骤停的特征和临床评估：关注特发性心室颤动

摘要 目的 最近的研究表明，在一半以上的明显原因不明的心脏骤停 (SCA) 中，通过仔细评估可以发现特定的病因。此类案件在现实生活中经过系统彻底调查的特征和程度尚不清楚。方法和结果 从一项正在进行的研究中分析数据，收集巴黎地区所有院外心脏骤停病例。收集指标住院期间或出院后计划进行的调查，以评估不明原因 SCA 评估的完整性。2011 年至 2016 年间，在 18 622 例院外心脏骤停中，717 名幸存者（出院时）符合心脏 SCA 的定义。其中，88 人（12.3%）在心电图、超声心动图、和冠状动脉造影。心脏磁共振成像在 25 例 (3.5%) 病例中产生了诊断，其他检查占 14 (2.4%) 例额外诊断，49 例 (6.8%) 患者被标记为特发性心室颤动 (IVF)（48.7 ± 15 岁，69.4 岁） ％ 男性）。在标记为 IVF 的患者中，只有 8 例（16.3%）受益于完整的检查（包括药理测试）。较年轻的患者 [比值比 (OR) 6.00，95% 置信区间 (CI) 1.80–22.26] 和住进大学中心的患者 (OR 3.60, 95% CI 1.12–12.45) 进行了更彻底的调查。基因检测和家庭筛查分别仅在 9 (18.4%) 和 12 (24.5%) 例中启动。结论 我们的研究结果表明，在非常低比例的无法解释的 SCA 中进行了完整的调查。标准化，