Aims Some patients with cardiac dystrophinopathy die suddenly. Whether such deaths are preventable by specific antiarrhythmic management or simply indicate heart failure overwhelming medical therapies is uncertain. The aim of this prospective, cohort study was to describe the occurrence and nature of cardiac arrhythmias recorded during prolonged continuous ECG rhythm surveillance in patients with established cardiac dystrophinopathy and relate them to abnormalities on cardiac MRI. Methods and results A cohort of 10 patients (36.3 years; 3 female) with LVEF<40% due to Duchenne (3) or Becker muscular (4) dystrophy or Duchenne muscular dystrophy-gene carrying effects in females (3) were recruited, had cardiac MRI, ECG signal-averaging and ECG loop-recorder implants. All were on standard of care heart medications and none had prior history of arrhythmias. No deaths or brady arrhythmias occurred during median follow-up 30 months (range 13–35). Self-limiting episodes of asymptomatic tachyarrhythmia (range 1–29) were confirmed in 8 (80%) patients (ventricular only 2; ventricular and atrial 6). Higher ventricular arrhythmia burden correlated with extent of myocardial fibrosis (extracellular volume%, p=0.029; native T1, p=0.49; late gadolinium enhancement, p=0.49), but not with LVEF% (p=1.0) on MRI and atrial arrhythmias with left atrial dilatation. Features of VT episodes suggested various underlying arrhythmia mechanisms. Conclusions The overall prevalence of arrhythmias was low. Even in such a small sample size, higher arrhythmia counts occurred in those with larger scar burden and greater ventricular volume, suggesting key roles for myocardial stretch as well as disease progression in arrhythmogenesis. These features overlap with the stage of left ventricular dysfunction when heart failure also becomes overt. The findings of this pilot study should help inform the design of a definitive study of specific antiarrhythmic management in dystrophinopathy. Trial registration number [ISRCTN15622536][1]. All data relevant to the study are included in the article or uploaded as online supplemental information. [1]: /external-ref?link_type=ISRCTN&access_num=ISRCTN15622536

中文翻译：

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已确诊的心脏肌营养不良症患者心律失常与心脏 MRI 的关联

目的 一些患有心脏营养不良症的患者突然死亡。这种死亡是否可以通过特定的抗心律失常治疗来预防，或者仅仅表明心力衰竭压倒了药物治疗，尚不确定。这项前瞻性队列研究的目的是描述已确诊的心脏肌营养不良患者在长期连续心电图节律监测期间记录的心律失常的发生和性质，并将其与心脏 MRI 异常联系起来。方法和结果 招募了 10 名因 Duchenne (3) 或 Becker 肌营养不良 (4) 或女性 (3) 携带 Duchenne 肌营养不良基因而导致 LVEF<40% 的患者（36.3 岁；3 名女性）。心脏 MRI、心电图信号平均和心电图循环记录器植入物。所有人都接受标准的心脏治疗药物治疗，并且没有人有心律失常病史。在中位随访 30 个月（范围 13-35）期间，没有发生死亡或缓慢性心律失常。 8 名 (80%) 患者证实有无症状快速心律失常（范围 1-29）的自限性发作（仅心室 2 例；心室和心房 6 例）。较高的室性心律失常负荷与心肌纤维化程度相关（细胞外体积%，p=0.029；天然T1，p=0.49；晚期钆增强，p=0.49），但与MRI和房性心律失常的LVEF%（p=1.0）无关伴有左心房扩张。室性心动过速发作的特征提示了各种潜在的心律失常机制。结论 心律失常的总体患病率较低。即使在如此小的样本量中，疤痕负担较大和心室容积较大的患者中发生的心律失常计数也较高，这表明心肌牵张以及疾病进展在心律失常发生中发挥着关键作用。当心力衰竭也变得明显时，这些特征与左心室功能障碍阶段重叠。这项试点研究的结果应有助于为肌营养不良症的特定抗心律失常治疗的确定性研究的设计提供信息。试用注册号 [ISRCTN15622536][1]。与研究相关的所有数据都包含在文章中或作为在线补充信息上传。 [1]: /external-ref?link_type=ISRCTN&access_num=ISRCTN15622536