Subramanian Muthiah, Prabhu Mukund A, Harikrishnan Madhavankutty Santhakumari, Shekhar Saritha S, Pai Praveen G, Natarajan Kumaraswamy
Department of Cardiology at Amrita Institute of Medical Sciences, Amritha Vishhwavidhyapeetham, Ponekkara, Kochi, Kerala, India.
J Cardiovasc Electrophysiol. 2017 Jun;28(6):677-683. doi: 10.1111/jce.13205. Epub 2017 Apr 20.
Risk stratification of asymptomatic patients with a Brugada type 1 ECG pattern remains an unresolved clinical conundrum. In contrast to provocative pharmacological testing in Brugada syndrome, there is limited data on the role of exercise stress testing as a risk stratification modality. The objective of this study was to evaluate the utility of exercise testing in asymptomatic patients with type 1 Brugada pattern to prognosticate major arrhythmic events (MAE) during follow-up.
Treadmill exercise testing was conducted for 75 asymptomatic patients with type 1 Brugada pattern and for 88 healthy control subjects. The clinical end point of MAE was defined as the occurrence of sudden cardiac death (SCD) or resuscitated ventricular fibrillation (VF). During a follow-up of 77.9 ± 28.9 months, eight MAE occurred (five VF and three SCD). Multivariate Cox regression analysis showed that the following were independent predictors of MAE in asymptomatic patients with a type 1 Brugada pattern: increase in S wave upslope duration ratio >30% at peak exercise (HR 1.35, 95% CI 1.08-10.97, P = 0.023), augmentation of J point elevation in lead aVR >2 mm in late recovery (HR 1.88, 95% 1.21-15.67, P = 0.011), and delayed HR recovery (HR 1.14, 95% CI 1.06-18.22, P = 0.042). A high-risk cohort was identified by the final step-wise regression model with good accuracy (specificity = 98.4%, sensitivity = 62.5%) and discriminative power (AUC = 0.93, 95% CI 0.89-0.96, P = 0.002). Kaplan-Meier analysis revealed increasing MAE in subjects with one, two, or three predictors, respectively (log rank P < 0.001).
Exercise testing in asymptomatic patients with type 1 Brugada pattern aids in identification of high-risk patients and provides a unique window of opportunity for early intervention.
无症状的1型Brugada心电图模式患者的风险分层仍然是一个尚未解决的临床难题。与Brugada综合征的激发性药物测试不同，关于运动负荷试验作为一种风险分层方式的作用的数据有限。本研究的目的是评估运动试验在无症状的1型Brugada模式患者中对随访期间主要心律失常事件（MAE）进行预后评估的效用。
对75例无症状的1型Brugada模式患者和88例健康对照者进行了跑步机运动试验。MAE的临床终点定义为心源性猝死（SCD）或复苏的室颤（VF）的发生。在77.9±28.9个月的随访期间，发生了8例MAE（5例VF和3例SCD）。多因素Cox回归分析显示，以下是无症状的1型Brugada模式患者MAE的独立预测因素：运动高峰时S波上升斜率持续时间比值增加>30%（HR 1.35，95%CI 1.08 - 10.97，P = 0.023）、恢复期晚期aVR导联J点抬高增加>2 mm（HR 1.88，95% 1.21 - 15.67，P = 0.011）以及心率恢复延迟（HR 1.14，95%CI 1.06 - 18.22，P = 0.042）。通过最终的逐步回归模型确定了一个高危队列，其具有良好的准确性（特异性 = 98.4%，敏感性 = 62.5%）和鉴别能力（AUC = 0.93，95%CI 0.89 - 0.96，P = 0.002）。Kaplan - Meier分析显示，分别具有一个、两个或三个预测因素的受试者中MAE发生率增加（对数秩检验P < 0.001）。
对无症状的1型Brugada模式患者进行运动试验有助于识别高危患者，并为早期干预提供独特的机会窗口。
