Department of Cardiology, Cardiovascular Institute of Havana, Cuba.
Department of Arrhythmias and Cardiac Pacing, Cardiovascular Institute of Havana, Cuba.
Rev Port Cardiol (Engl Ed). 2020 Apr;39(4):183-186. doi: 10.1016/j.repc.2019.07.009. Epub 2020 May 13.
Corrected QT interval (QTc) >460 ms in the right precordial leads has been described as a predictor of malignant ventricular arrhythmias (MVA) in patients with Brugada syndrome (BrS).
To assess the presence of QTc>460 ms in multiple electrocardiograms (ECGs) during follow-up as a predictor of recurrence of MVA in patients with BrS.
The study group included 43 patients with BrS and an implantable cardioverter-defibrillator. ECGs were performed serially between June 2000 and January 2017. QT interval was measured and QTc was obtained by Bazett's formula. The sample was divided into three groups: Group 1 (patients with no ECGs with QTc>460 ms); Group 2 (patients with only one ECG with QTc>460 ms); and Group 3 (patients with two or more ECGs with QTc>460 ms).
The following variables were more frequently observed in Group 3: family history of sudden death (p=0.023), previous history of cardiorespiratory arrest (p=0.032), syncope (p=0.039), documented MVA (p=0.002), and proportion of ECGs with coved-type ST interval during follow-up (p=0.002). In Group 3, 67% of BrS patients had events during follow-up, as opposed to only 22% of Group 1 and 14% of Group 2 (Group 1 vs. Group 2, p=0.33015; Group 1 vs. Group 3, p=0.04295; and Group 2 vs. Group 3, p=0.04155).
QTc>460 ms in more than one ECG during follow-up increases the risk of MVA events in patients with BrS.
右胸导联的校正 QT 间期（QTc）>460ms 已被描述为 Brugada 综合征（BrS）患者恶性室性心律失常（MVA）的预测因子。
评估 BrS 患者在随访期间多次心电图（ECG）中 QTc>460ms 的存在情况，作为预测 MVA 复发的指标。
研究组包括 43 例植入式心脏复律除颤器的 BrS 患者。心电图在 2000 年 6 月至 2017 年 1 月期间连续进行。测量 QT 间期，并通过 Bazett 公式得出 QTc。将样本分为三组：第 1 组（无 QTc>460ms 的心电图）；第 2 组（仅有 1 份 QTc>460ms 的心电图）；第 3 组（2 份或更多份 QTc>460ms 的心电图）。
第 3 组患者更常出现以下变量：猝死家族史（p=0.023）、心肺复苏前史（p=0.032）、晕厥（p=0.039）、有记录的 MVA（p=0.002）以及随访期间心电图中出现 coved 型 ST 段的比例（p=0.002）。在第 3 组中，67%的 BrS 患者在随访期间发生了事件，而第 1 组仅为 22%，第 2 组为 14%（第 1 组与第 2 组，p=0.33015；第 1 组与第 3 组，p=0.04295；第 2 组与第 3 组，p=0.04155）。
在随访期间，超过一份 ECG 中出现 QTc>460ms 会增加 BrS 患者发生 MVA 事件的风险。
