Department of Cardiology, Hospital Oost-Limburg, Genk, Belgium; Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium.
Division of Cardiology, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts.
J Am Soc Echocardiogr. 2021 Feb;34(2):156-165. doi: 10.1016/j.echo.2020.09.009. Epub 2020 Oct 29.
Occult atrial fibrillation (AF) is an important contributor to cryptogenic stroke, yet remains difficult to unmask at presentation. This study investigated the predictive value of left atrial (LA) mechanics by strain echocardiography during stroke hospitalization for the presence of AF as detected on early 30-day monitoring and routine clinical follow-up.
Left atrial mechanics were studied by strain echocardiography in a retrospective cohort of 191 patients with cryptogenic stroke and 30-day mobile cardiac outpatient telemetry poststroke to diagnose AF. After this, AF was diagnosed via routine clinical follow-up. The independent and incremental value of measures of LA size and mechanics (i.e., strain and strain rate in the reservoir, conduit, and booster pump phase) to predict AF on top of clinical characteristics was assessed.
Of 191 patients, 15% (n = 28) developed AF, of which 10 were observed during 30-day mobile cardiac outpatient telemetry and 18 were observed at a median follow-up of 25 (interquartile range, 10-43) months. Median time from embolic stroke to strain echocardiography was 1 day (interquartile range, 1-2 days). Left atrial mechanics were significantly worse in AF (P < .05 for all), despite largely similar baseline cardiovascular risk profile. Booster pump strain rate was the strongest predictor for AF, independent of age, LA volume index, E/e', and reservoir strain (odds ratio = 2.88 per SD increase; 95% confidence interval, 1.29-6.41; P = .010). Adding LA strain reservoir strain and booster pump function significantly enhanced a multivariate model to predict AF. Freedom from AF was significantly lower in subjects with a booster pump strain rate (at stroke presentation) worse than -0.67 sec, as derived from receiver operator curve analysis (P < .001).
Left atrial mechanics and particularly the LA booster pump function assessed early during hospitalization for cryptogenic stroke can identify patients at greater likelihood of future diagnosis of AF. These findings could in part relate to LA mechanical stunning after spontaneous cardioversion, which-when identified by early strain echocardiography-can inform further risk stratification and decision-making.
隐匿性心房颤动（AF）是引起隐源性卒中的重要因素，但在发病时仍难以发现。本研究通过应变超声心动图研究了卒中住院期间左心房（LA）力学对早期 30 天监测和常规临床随访中发现的 AF 存在的预测价值。
通过应变超声心动图对 191 例隐源性卒中患者进行研究，并在卒中后进行 30 天移动心脏门诊远程监测以诊断 AF，同时进行 LA 大小和力学（即储备、传导和升压泵阶段的应变和应变速率）的测量。然后通过常规临床随访诊断 AF。评估 LA 大小和力学（即储备、传导和升压泵阶段的应变和应变速率）测量值对临床特征预测 AF 的独立和增量价值。
在 191 例患者中，15%（n=28）发生 AF，其中 10 例在 30 天移动心脏门诊远程监测期间观察到，18 例在中位随访 25 个月（四分位距 10-43）时观察到。从栓塞性卒中到应变超声心动图的中位时间为 1 天（四分位距 1-2 天）。尽管基线心血管风险谱大致相似，但 AF 患者的左心房力学明显较差（所有 P<0.05）。升压泵应变速率是 AF 的最强预测因子，独立于年龄、LA 容积指数、E/e'和储备应变（优势比每 SD 增加 2.88；95%置信区间，1.29-6.41；P=0.010）。加入 LA 储备应变和升压泵功能可显著提高预测 AF 的多变量模型。根据受试者工作特征曲线分析，升压泵应变率（卒中时）< -0.67 sec 的患者 AF 发生率明显较低（P<0.001）。
隐源性卒中住院期间早期评估的左心房力学，特别是 LA 升压泵功能，可识别出未来更有可能诊断 AF 的患者。这些发现部分可能与自发电复律后 LA 机械性休克有关，早期应变超声心动图发现这种情况可以进一步进行风险分层和决策。
