Background: Atrial fibrillation (AF), the most common sustained arrhythmia in hypertrophic cardiomyopathy (HCM), is capable of producing symptoms that impact quality of life and is associated with risk for embolic stroke. However, the influence of AF on clinical course and outcome in HCM remains incompletely resolved.

Methods: Records of 1558 consecutive patients followed at the Tufts Medical Center Hypertrophic Cardiomyopathy Institute for 4.8±3.4 years (from 2004 to 2014) were accessed.

Results: Of the 1558 patients with HCM, 304 (20%) had episodes of AF, of which 226 (74%) were confined to symptomatic paroxysmal AF (average, 5±5; range, 1 to >20), whereas 78 (26%) developed permanent AF, preceded by 7±6 paroxysmal AF episodes. At last evaluation, 277 patients (91%) are alive at 62±13 years of age, including 89% in New York Heart Association class I or II. No difference was found in outcome measures for patients with AF and age- and sex-matched patients with HCM without AF. Four percent of patients with AF died of HCM-related causes (n=11), with annual mortality 0.7%; mortality directly attributable to AF (thromboembolism without prophylactic anticoagulation) was 0.1% per year (n=2 patients). Patients were treated with antiarrhythmic drugs (most commonly amiodarone [n=103] or sotalol [n=78]) and AF catheter ablation (n=49) or the Maze procedure at surgical myectomy (n=72). Freedom from AF recurrence at 1 year was 44% for ablation patients and 75% with the Maze procedure (P<0.001). Embolic events were less common with anticoagulation prophylaxis (4/233, 2%) than without (9/66, 14%) (P<0.001).

Conclusions: Transient symptomatic episodes of AF, often responsible for impaired quality of life, are unpredictable in frequency and timing, but amenable to effective contemporary treatments, and infrequently progress to permanent AF. AF is not a major contributor to heart failure morbidity or a cause of arrhythmic sudden death; when treated, it is associated with low disease-related mortality, no different than for patients without AF. AF is an uncommon primary cause of death in HCM virtually limited to embolic stroke, supporting a low threshold for initiating anticoagulation therapy.

背景：房颤（AF）是肥厚型心肌病（HCM）中最常见的持续性心律失常，能够产生影响生活质量的症状，并伴有栓塞性中风的风险。然而，房颤对HCM临床病程和预后的影响仍未完全解决。

方法：获得塔夫茨医学中心肥厚型心肌病研究所随访的1558例患者的记录，记录时间为4.8±3.4年（从2004年至2014年）。

结果：在1558例HCM患者中，有304（20％）发生了房颤发作，其中226（74％）限于有症状的阵发性房颤（平均5±5；范围从1到> 20），而78例（26％） ）发展为永久性房颤，然后出现7±6阵发性房颤发作。在最后一次评估中，有277名患者（91％）活着，年龄在62±13岁，其中包括纽约心脏协会I级或II级的89％。对于房颤患者以及年龄和性别相匹配的无房颤的HCM患者，其结局指标均无差异。4％的AF患者死于HCM相关原因（n = 11），年死亡率为0.7％。每年直接归因于AF（无预防性抗凝的血栓栓塞）的死亡率为0.1％（n = 2例）。患者接受了抗心律不齐药物（最常见的是胺碘酮[n = 103]或索他洛尔[n = 78]）和AF导管消融术[n = 49]或在手术肌瘤切除术中进行了迷宫手术[n = 72]。消融患者在1年时无房颤复发的可能性为44％，迷宫手术为75％（P <0.001）。预防性栓塞事件的栓塞事件较少（4 / 233，2％），而没有抗凝剂的栓塞事件（9 / 66，14％）较少（P <0.001）。

结论：房颤的短暂性症状发作通常是生活质量受损的原因，其频率和时机无法预测，但可以接受有效的当代治疗，并且很少进展为永久性房颤。AF不是导致心力衰竭发病率或心律失常性猝死的主要原因；接受治疗后，与疾病相关的死亡率低，与没有AF的患者没有什么不同。AF是HCM中罕见的主要死亡原因，实际上仅限于栓塞性中风，支持开始抗凝治疗的低阈值。