Background

Fascicular heart blocks can progress to complete heart blocks, but this risk has not been evaluated in a large general population.

Objective

The purpose of this study was to investigate the association between various types of fascicular blocks diagnosed by electrocardiographic (ECG) readings and the risk of incident higher degree atrioventricular block (AVB), syncope, pacemaker implantation, and death.

Methods

We studied primary care patients referred for ECG recording between 2001 and 2015. Cox regression models were used to estimate hazard ratios (HRs) as well as absolute risks of cardiovascular outcomes.

Results

Of 358,958 primary care patients (median age 54 years; 55% women), 13,636 (3.8%) had any type of fascicular block. Patients were followed up to 15.9 years. We found increasing HRs of incident syncope, pacemaker implantation, and third-degree AVB with increasing complexity of fascicular block. Compared with no block, isolated left anterior fascicular block (LAFB) was associated with 0%–2% increased 10-year risk of developing third-degree AVB (HR 1.6; 95% confidence interval [CI] 1.25–2.05), whereas right bundle branch block combined with LAFB and first-degree AVB was associated with up to 23% increased 10-year risk (HR 11.0; 95% CI 7.7–15.7), depending on age and sex group. Except for left posterior fascicular block (HR 2.09; 95% CI 1.87–2.32), we did not find any relevant associations between fascicular block and death.

Conclusion

We found that higher degrees of fascicular blocks were associated with increasing risk of syncope, pacemaker implantation, and complete heart block, but the association with death was negligible.

中文翻译：

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束状心脏传导阻滞和心血管不良后果的风险：来自大量初级保健人群的结果

背景

束状心脏传导阻滞可进展为完全性心脏传导阻滞，但尚未在大量普通人群中评估这种风险。

客观的

本研究的目的是调查通过心电图 (ECG) 读数诊断的各种类型的束状传导阻滞与发生高度房室传导阻滞 (AVB)、晕厥、起搏器植入和死亡的风险之间的关联。

方法

我们研究了 2001 年至 2015 年间转诊进行心电图记录的初级保健患者。Cox 回归模型用于估计风险比 (HR) 以及心血管结局的绝对风险。

结果

在 358,958 名初级保健患者（中位年龄 54 岁；55% 为女性）中，13,636 名（3.8%）患有任何类型的束状传导阻滞。患者随访至 15.9 年。我们发现随着束状传导阻滞复杂性的增加，发生晕厥、起搏器植入和三度 AVB 的 HR 增加。与无阻滞相比，孤立的左前束支阻滞 (LAFB) 与 10 年发生三度 AVB 的风险增加 0%–2% 相关（HR 1.6；95% 置信区间 [CI] 1.25–2.05），而右侧束支传导阻滞联合 LAFB 和一级 AVB 与高达 23% 的 10 年风险增加相关（HR 11.0；95% CI 7.7-15.7），具体取决于年龄和性别组。除了左后束传导阻滞（HR 2.09；95% CI 1.87-2.32），我们没有发现束传导阻滞与死亡之间的任何相关关联。

结论

我们发现，较高程度的束状传导阻滞与晕厥、起搏器植入和完全性心脏传导阻滞的风险增加相关，但与死亡的相关性可以忽略不计。