Solbiati Monica, Casazza Giovanni, Dipaola Franca, Barbic Franca, Caldato Maja, Montano Nicola, Furlan Raffaello, Sheldon Robert S, Costantino Giorgio
Dipartimento di Medicina Interna e Specializzazioni Mediche, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milano, Italy; Dipartimento di Scienze Cliniche e di Comunità, Università degli Studi di Milano, Milano, Italy.
Dipartimento di Scienze Biomediche e Cliniche "L. Sacco", Università degli Studi di Milano, Milano, Italy.
Int J Cardiol. 2017 Mar 15;231:170-176. doi: 10.1016/j.ijcard.2016.12.128. Epub 2016 Dec 22.
Guidelines recommend that implantable loop recorders (ILRs) are used in the evaluation of people with recurrent unexplained syncope in the absence of high-risk criteria, and in high-risk patients after a negative evaluation. The aim of this systematic review was to analyze the diagnostic yield of ILRs in these patients.
We performed a systematic search in order to retrieve studies enrolling adults undergoing ILR implantation for undetermined syncope. The primary outcome was the overall diagnostic yield, defined as the proportion of patients with syncope recurrence and an available ILR recording or an automatic detection of a significant arrhythmia. Secondary outcomes were the proportions of patients with the specific etiologic diagnoses on the total of subjects and the proportion of an analyzable ECG recording during symptoms. We used a random effects model for the meta-analyses.
Forty-nine studies, enrolling 4381 subjects, were included. The overall diagnostic yield was 43.9% (95% CI=40.2%, 47.6%; I=79.8%). The proportions of subjects finally diagnosed with arrhythmic syncope, ventricular arrhythmias, supraventricular arrhythmias and bradyarrhythmias were 26.5%, 2.7%, 4.9% and 18.2%, respectively. The proportion of an analyzable ECG recording during symptoms was 89.5% (95% CI=86.1%, 92.1%; 1236 subjects; 36 studies; I=44.9%). Median time to diagnosis was 134days. Heterogeneity is an important limitation to be acknowledged.
About a half of unexplained syncope subjects implanted with an ILR were diagnosed, and around 50% of them had an arrhythmia. Life-threatening arrhythmias as well as ILR complications and death due to arrhythmic events were very rare.
指南建议，在无高危标准的复发性不明原因晕厥患者评估中以及在评估结果为阴性的高危患者中使用植入式循环记录仪（ILR）。本系统评价的目的是分析ILR在这些患者中的诊断率。
我们进行了系统检索，以获取纳入因不明原因晕厥接受ILR植入的成人的研究。主要结局是总体诊断率，定义为晕厥复发且有可用的ILR记录或自动检测到显著心律失常的患者比例。次要结局是在所有受试者中确诊特定病因诊断的患者比例以及症状发作期间可分析心电图记录的比例。我们使用随机效应模型进行荟萃分析。
纳入了49项研究，共4381名受试者。总体诊断率为43.9%（95%CI=40.2%，47.6%；I²=79.8%）。最终被诊断为心律失常性晕厥、室性心律失常、室上性心律失常和缓慢性心律失常的受试者比例分别为26.5%、2.7%、4.9%和18.2%。症状发作期间可分析心电图记录的比例为89.5%（95%CI=86.1%，92.1%；1236名受试者；36项研究；I²=44.9%）。诊断的中位时间为134天。异质性是一个需要承认的重要局限性。
植入ILR的不明原因晕厥受试者中约有一半得到诊断，其中约50%患有心律失常。危及生命的心律失常以及ILR并发症和心律失常事件导致的死亡非常罕见。
