Rai Maneesh K, Prabhu Mukund A, Shenthar Jayaprakash, Kumaraswamy U Natarajan, Vekariya Ritesh, Kamath Padmanabh, Pai Narasimha, Kamath Ramanath L, Pillai Vivek
Department of Cardiology, Kasturba Medical College, Mangalore, Karnataka, India.
Department of Cardiology, Amrita Institute of Medical Sciences, Kochi, Kerala, India.
Indian Pacing Electrophysiol J. 2017 Jul-Aug;17(4):102-107. doi: 10.1016/j.ipej.2017.04.002. Epub 2017 May 3.
We analyzed Lead II in patients undergoing an Oral Flecainide Challenge test (FCT), to identify any pointers that could predict a positive FCT and thereby help in recognition of latent BS.
The following parameters in lead II were retrospectively analyzed from the pre-test ECG in 62 patients undergoing FCT for suspected BS: The presence or absence of S waves, S wave amplitude, duration and upslope duration; J point parameters- Early repolarization, QRS notch, and QRS Slur; ST segment parameters-lack of isoelectric ST segment, ST duration and QT interval.
48 had positive FCT (Group-1) while 14 were negative for FCT(Group-2). Lack of an isoelectric ST segment (50% vs 14.29%, p = 0.018) and slurring of QRS (33.33% vs 0%, p = 0.014) was more common in Group-1 than Group-2. Group-1 had shorter ST segment duration (median 81.5 (IQR 64-103.5) vs 110 (IQR 90-132), p = 0.002) and shorter ST: QT ratio (median 0.28 (IQR 0.22-0.35) vs 0.23 (0.18-0.27), p = 0.007). QRS notch/depressed J point (87.5%), QRS slur (100%), and lack of isoelectric ST segment (92.31%) had high sensitivity for predicting an inducible Type 1 Brugada pattern. Combining two parameters- ST: QT ratio<0.24 and lack of isoelectric ST segment-considerably improved the specificity (73.3%), and the positive predictive value of the test to 76%. The results remained accurate when validated in a small prospective cohort.
Shortened ST segment in Lead II, lack of isoelectric ST segment, slurred QRS and ST/QT ratio <0.24 are predictive of underlying Brugada pattern in baseline ECG.
我们对接受口服氟卡尼激发试验（FCT）的患者的II导联进行分析，以确定任何可预测FCT阳性的指标，从而有助于识别潜在的布加综合征（BS）。
对62例因疑似BS接受FCT的患者，回顾性分析其试验前心电图II导联的以下参数：S波的有无、S波振幅、时长及上升支时长；J点参数——早期复极、QRS切迹和QRS顿挫；ST段参数——等电位ST段缺失、ST段时长和QT间期。
48例FCT阳性（第1组），14例FCT阴性（第2组）。第1组中，等电位ST段缺失（50% 对14.29%，p = 0.018）和QRS顿挫（33.33% 对0%，p = 0.014）比第2组更常见。第1组的ST段时长较短（中位数81.5（四分位间距64 - 103.5）对110（四分位间距90 - 132），p = 0.002），ST:QT比值较短（中位数0.28（四分位间距0.22 - 0.35）对0.23（0.18 - 0.27），p = 0.007）。QRS切迹/压低的J点（87.5%）、QRS顿挫（达100%）和等电位ST段缺失（92.31%）对预测可诱发的1型布加综合征心电图表现具有高敏感性。联合两个参数——ST:QT比值<0.24和等电位ST段缺失——可显著提高特异性（达73.3%），且试验的阳性预测值达76%。在一个小型前瞻性队列中验证时，结果依然准确。
II导联ST段缩短、等电位ST段缺失、QRS顿挫及ST/QT比值<0.24可预测基线心电图中的潜在布加综合征心电图表现。
