Adult Congenital Heart Disease and Congenital and Familial Arrhythmias Unit, Monaldi Hospital, Naples, Italy.
Dipartimento di Biochimica e Biotecnologie Mediche, University of Naples "Federico II", Naples, Italy.
J Cardiovasc Electrophysiol. 2024 Oct;35(10):1941-1951. doi: 10.1111/jce.16384. Epub 2024 Jul 31.
Early-onset atrial fibrillation (AF) has already been observed in approximately 2% of patients with genetically proven long QT syndrome (LQTS). This frequency is higher than population-based estimates of early-onset AF. However, the concomitant expression of AF in LQTS is likely underestimated. The purpose of this study was to examine the clinical presentation, genetic background, and outcomes of a cohort of patients with LQTS and early-onset AF referred to a single tertiary center.
Twenty-seven patients diagnosed with congenital LQTS were included in the study based on the documentation of early-onset (age ≤50 years) clinical or subclinical AF episodes in all available medical records, including standard electrocardiograms, wearable monitor or cardiac implantable electronic devices.
Seventeen patients experienced clinical AF during the follow-up period. Subclinical AF was detected in 10 patients through insertable or wearable cardiac monitors. In our series, the mean heart rate during AF episodes was found to be relatively low despite the patients' young age and the low or minimal effective doses of beta-blockers used for QTc interval control. All patients exhibiting LQTS and early-onset AF were genotype positive, carrying mutations in the KCNQ1 (66%), KCNH2, KCNE1, and SCN5A genes. Notably, most of these patients carried the same p.(R231C) mutation in the KCNQ1 gene (59%) and were from the same families, suggesting concurrent expression of familial AF and LQTS.
LQTS patients are prone to developing clinical and subclinical AF, even at a younger age. The occurrence of early-onset AF in the LQTS population could be more frequent than previously assumed. AF should be considered as a potential dysrhythmia related to LQTS. Our study emphasizes the importance of carefully researching clinical and/or subclinical episodes of AF through strict heart rhythm monitoring in the LQTS population.
在已证实存在基因突变的长 QT 综合征（LQTS）患者中，约有 2%已出现早期房颤（AF）。这一频率高于人群中对早期 AF 的预估。然而，LQTS 患者同时发生 AF 的情况可能被低估了。本研究的目的是调查一个单中心转诊的 LQTS 合并早期 AF 患者队列的临床表现、遗传学背景和结局。
根据所有可用病历记录中记录的早期（年龄≤ 50 岁）临床或亚临床 AF 发作，包括标准心电图、可穿戴监测仪或心脏植入式电子设备，研究纳入了 27 名确诊为先天性 LQTS 的患者。
17 名患者在随访期间出现了临床 AF。通过植入式或可穿戴心脏监测仪发现了 10 名患者的亚临床 AF。在我们的系列研究中，尽管患者年龄较小且用于 QTc 间期控制的β受体阻滞剂的低或最小有效剂量，AF 发作期间的平均心率仍相对较低。所有表现出 LQTS 和早期 AF 的患者均为基因突变阳性，携带 KCNQ1（66%）、KCNH2、KCNE1 和 SCN5A 基因突变。值得注意的是，这些患者中大多数携带 KCNQ1 基因相同的 p.(R231C)突变（59%），且来自同一家庭，提示家族性 AF 和 LQTS 同时存在。
LQTS 患者极易出现临床和亚临床 AF，甚至在更年轻时就会出现。LQTS 人群中早期 AF 的发生可能比之前认为的更为频繁。AF 应被视为与 LQTS 相关的潜在心律失常。我们的研究强调了在 LQTS 人群中通过严格的心律监测仔细研究临床和/或亚临床 AF 发作的重要性。
