Background

Friedreich ataxia is the most commonly inherited ataxia; nearly 60% of deaths are cardiac in nature, with one in eight deaths due to arrhythmia. Additional or irregular heartbeats, measured as ectopy, can be quantified using portable heart rhythm monitoring. We sought to describe the ectopic burden in Friedreich ataxia.

Methods

Using a natural history study of patients with Friedreich ataxia at a single center, we analyzed portable heart rhythm monitors (Holters). Ectopic burden was defined as the proportion of atrial or ventricular ectopic beats over total beats.

Results

Of 456 patients, 131 had Holters. Sixty-eight (52.0%) were male, median age of symptom onset was 8.0 years (5.0 to 13.0, n = 111), median age at time of Holter was 17.3 years (interquartile range [IQR] 12.9 to 22.8, n = 129), and median duration of illness was 8.7 years (IQR 5.3 to 11.6, n = 110). Median GAA length on the shorter FXN allele was 706.0 (IQR 550.0 to 840.0, n = 112). Eight (7.8%, n = 103) had diminished cardiac function, and 74 (74.0%, n = 100) had ventricular hypertrophy. Ninety patients (83.0%) had atrial ectopy (supraventricular ectopy [SVE]): 85 (78.0%) with rare SVE (>0% to 5%) and five (5.0%) with frequent SVE (>10%). Twenty-five (19.0%) had supraventricular runs, and one (0.8%) had atrial fibrillation/flutter. Forty-five (41.0%) had ventricular ectopy (VE): 43 (39.0%) with rare VE (0% to 5%) and two (2.0%) with moderate VE (5% to 10%). Compared with patients with none and rare SVE, patients with frequent SVE had longer disease duration (18.3 versus 4.6 versus 9.0 years, P = 0.0005).

Conclusion

Patients with longer disease duration had higher rates of SVE. Heart rhythm monitoring may be considered for risk stratification; however, longitudinal analysis is needed.

中文翻译：

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弗里德赖希共济失调中通过动态心电图监测的异位负担

背景

弗里德赖希共济失调是最常见的遗传性共济失调；近 60% 的死亡是心脏性的，八分之一的人死于心律失常。额外的或不规则的心跳，测量为异位，可以使用便携式心律监测来量化。我们试图描述弗里德赖希共济失调的异位负担。

方法

我们对单个中心的 Friedreich 共济失调患者进行自然史研究，分析了便携式心律监测仪 (Holters)。异位负荷定义为心房或心室异位搏动占总搏动的比例。

结果

在 456 名患者中，131 名进行了动态心电图检查。68 人 (52.0%) 为男性，症状发作的中位年龄为 8.0 岁（5.0 至 13.0，n = 111），Holter 时的中位年龄为 17.3 岁（四分位距 [IQR] 12.9 至 22.8，n = 129 )，中位病程为 8.7 年（IQR 5.3 至 11.6，n = 110）。较短FXN上的中值 GAA 长度等位基因为 706.0（IQR 550.0 至 840.0，n = 112）。8 人（7.8%，n = 103）心功能减退，74 人（74.0%，n = 100）心室肥大。90 名患者 (83.0%) 患有心房异位症（室上性异位症 [SVE]）：85 名 (78.0%) 患有罕见的 SVE (>0% 至 5%)，5 名 (5.0%) 患有频繁的 SVE (>10%)。25 人 (19.0%) 有室上性奔跑，1 人 (0.8%) 有心房颤动/扑动。45 人 (41.0%) 患有室性异位症 (VE)：43 人 (39.0%) 患有罕见 VE (0% 至 5%)，2 人 (2.0%) 患有中度 VE (5% 至 10%)。与无和罕见 SVE 患者相比，频繁 SVE 患者的病程更长（18.3 年 vs 4.6 年 vs 9.0 年，P  = 0.0005）。

结论

病程较长的患者 SVE 发生率较高。可考虑监测心律以进行风险分层；但是，需要进行纵向分析。