Laboratório de Pesquisa de Patofisiologia do Exercício, Divisão de Cardiologia, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
Arq Bras Cardiol. 2011 Jul;97(1):26-32. doi: 10.1590/s0066-782x2011005000054. Epub 2011 May 6.
Exercise-induced left bundle branch block (EI-LBBB) is an infrequent finding. Its prevalence and prognostic significance are not clear.
To evaluate, in a longitudinal study, the prevalence and prognostic significance of EI-LBBB in American war veterans.
We evaluated 9,623 patients submitted to an exercise test (ET) in treadmill between 1987 and 2007. The outcomes were compared between those with normal TE, the ones with EI-LBBB and the ones with down-sloping ST-segment. Mortality and causes of death were identified while blinded to the ET results.
In this prospective cohort, 6,922 individuals had normal ET results (57.2 ± 11.4 years), 1,739 had abnormal ST-segment depression (62.7 ± 9.8 years), and 38 had EI-LBBB (65.2 ± 11.9 years). The prevalence of EI-LBBB was 0.38%. After 8.8 years, there were 1,699 deaths due to all-cause mortality and 610 cardiovascular (CV) deaths; coronary artery disease and heart failure were more prevalent in patients with EI-LBBB. Patients with EI-BCRE had a hazard ratio of 2.37 (p = 0.002) for all-cause mortality, but it was not significant when adjusted for age or when the CV death was the assessed outcome.
EI-LBBB is a rare clinical finding. Individuals with BCRE-EI have higher all-cause mortality when compared to those with normal ET results. However, this fact is explained by the fact that these patients are significantly older and have more associated cardiovascular diseases.
运动诱发的左束支传导阻滞（EI-LBBB）是一种不常见的发现。其患病率和预后意义尚不清楚。
在一项纵向研究中，评估美国退伍军人中 EI-LBBB 的患病率和预后意义。
我们评估了 1987 年至 2007 年间在跑步机上进行运动试验（ET）的 9623 例患者。将正常 TE、EI-LBBB 和下斜 ST 段的患者的结果进行比较。在不了解 ET 结果的情况下，确定死亡率和死因。
在这个前瞻性队列中，6922 人有正常的 ET 结果（57.2±11.4 岁），1739 人有异常的 ST 段压低（62.7±9.8 岁），38 人有 EI-LBBB（65.2±11.9 岁）。EI-LBBB 的患病率为 0.38%。8.8 年后，共有 1699 人死于全因死亡率，610 人死于心血管（CV）死亡率；EI-LBBB 患者更常见冠心病和心力衰竭。EI-BCRE 患者的全因死亡率风险比为 2.37（p=0.002），但在调整年龄或评估 CV 死亡为结果时，差异无统计学意义。
EI-LBBB 是一种罕见的临床发现。与正常 ET 结果的患者相比，EI-LBBB 患者的全因死亡率更高。然而，这一事实可以用这些患者年龄较大且有更多相关心血管疾病的事实来解释。
