Department of Cardiology, Southlake Regional Health Centre, 105-712 Davis Dr, Newmarket, ON L3Y 8C3, Canada.
JAMA Intern Med. 2013 Jan 28;173(2):149-56. doi: 10.1001/jamainternmed.2013.1561.
The DISCERN AF study (Discerning Symptomatic and Asymptomatic Episodes Pre and Post Radiofrequency Ablation of Atrial Fibrillation) monitored atrial fibrillation (AF) using an implantable cardiac monitor (ICM) to assess the incidence and predictors of asymptomatic AF before and after catheter ablation.
Patients with symptomatic AF underwent implantation of an ICM with an automated AF detection algorithm 3 months before and 18 months after ablation. Patients kept a standardized diary to record symptoms of arrhythmia, and ICM data were downloaded every 3 months. All episodes were blindly adjudicated and correlated with the diary. Asymptomatic recurrences were ICM episodes of 2 minutes or longer with no associated diary symptoms.
Fifty patients had 2355 ICM episodes. Of these, 69.0% were true AF/atrial flutter (AFL)/atrial tachycardia (AT); 16.0%, sinus with extrasystoles; 11.0%, artifact; and 4.0%, sinus arrhythmia. Total AF/AFL/AT burden was reduced by 86% from a mean (SD) of 2.0 (0.5) h/d per patient before to 0.3 (0.2) h/d per patient after ablation (P < .001), and 56.0% of all episodes were asymptomatic. The ratio of asymptomatic to symptomatic AF episodes increased after ablation from 1.1 to 3.7 (P = .002). By symptoms alone, 29 of 50 patients (58%) were free of AF/AFL/AT after ablation compared with 23 of 50 (46%) using ICM-detected AF/AFL/AT recurrence. Asymptomatic episodes were more likely AFL/AT and were significantly shorter and slower, with lower heart rate variability. However, the postablation state was the strongest independent predictor of asymptomatic AF.
The ratio of asymptomatic to symptomatic AF episodes increased from 1.1 before to 3.7 after ablation. Postablation state is the strongest predictor of asymptomatic AF. Symptoms alone underestimate postablation AF burden, with 12% of patients having asymptomatic recurrences only.
clinicaltrials.gov Identifier: NCT00745706.
DISCERN AF 研究（监测心房颤动射频消融前后症状性和无症状性发作的辨别）使用植入式心脏监测器（ICM）监测心房颤动（AF），以评估导管消融前后无症状性 AF 的发生率和预测因素。
有症状性 AF 的患者在消融前 3 个月和消融后 18 个月植入具有自动 AF 检测算法的 ICM。患者记录心律失常症状的标准化日记，并每 3 个月下载一次 ICM 数据。所有发作均进行盲法裁决，并与日记相关联。无症状复发是指 ICM 发作持续 2 分钟或更长时间，且无相关日记症状。
50 例患者共发生 2355 次 ICM 发作。其中，69.0%为真实 AF/房扑（AFL）/房性心动过速（AT）；16.0%为窦性伴早搏；11.0%为伪差；4.0%为窦性心律失常。总 AF/AFL/AT 负荷从患者平均（标准差）每天 2.0（0.5）小时降至消融后每天 0.3（0.2）小时（P<0.001），且 56.0%的发作均无症状。消融后无症状 AF 发作与有症状 AF 发作的比值从 1.1 增加至 3.7（P=0.002）。仅根据症状，与 50 例患者中的 29 例（58%）相比，50 例患者中有 23 例（46%）使用 ICM 检测到的 AF/AFL/AT 复发后无 AF/AFL/AT。无症状发作更可能为 AFL/AT，且明显更短和更慢，心率变异性更低。然而，消融后状态是无症状 AF 的最强独立预测因素。
无症状 AF 发作与有症状 AF 发作的比值从消融前的 1.1 增加至消融后的 3.7。消融后状态是无症状 AF 的最强预测因素。仅凭症状会低估消融后的 AF 负担，12%的患者仅有无症状复发。
clinicaltrials.gov 标识符：NCT00745706。
