Kataoka Naoya, Nagase Satoshi, Imamura Teruhiko, Kinugawa Koichiro
Second Department of Internal Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Japan.
Eur Heart J Case Rep. 2023 Aug 3;7(8):ytad377. doi: 10.1093/ehjcr/ytad377. eCollection 2023 Aug.
The area of abnormal bipolar potentials in the right ventricular epicardium is recognized as an arrhythmogenic substrate in patients with Brugada syndrome (BrS); however, the correlation between local potentials and Brugada-type surface electrocardiograms (ECGs) remains unclear.
A 49-year-old man with BrS who was hospitalized for refractory ventricular fibrillation underwent an electrocardiographic study with unipolar electrodes with the same bandwidth as surface ECGs. The right ventricular outflow tract epicardium showed abnormal bipolar potentials composed of split sharp and delayed dull components with coved-type J-ST elevation in the unipolar electrodes. The additional stimuli from the atrium gradually decreased the number of unipolar electrodes showing coved-type J-ST elevation along with a shortening of the local bipolar activation time. The pilsicainide provocation test induced a change in unipolar morphology from coved type to convex type and an intermittent local block of the divided and sharp components in bipolar electrodes. Of note, the unipolar J-ST elevation was not changed along with the localized conduction block in bipolar leads.
The unipolar electrode waveforms during sinus rhythm change together with bipolar electrodes, consisting of sharp and blunt components in BrS. However, the convex-type J-ST elevation in unipolar leads persisted irrespective of the local conduction block in bipolar leads after pilsicainide provocation. These findings suggest the complexity of BrS mechanisms.
右心室心外膜异常双极电位区域被认为是Brugada综合征（BrS）患者的致心律失常基质；然而，局部电位与Brugada型体表心电图（ECG）之间的相关性仍不清楚。
一名49岁的BrS男性因难治性室颤住院，接受了与体表ECG带宽相同的单极电极心电图研究。右心室流出道心外膜在单极电极中显示出由分裂的尖锐成分和延迟的钝成分组成的异常双极电位，伴有穹窿型J点抬高。心房的额外刺激逐渐减少了显示穹窿型J点抬高的单极电极数量，同时局部双极激活时间缩短。吡西卡尼激发试验导致单极形态从穹窿型变为凸型，并使双极电极中分裂的尖锐成分出现间歇性局部阻滞。值得注意的是，单极J点抬高并未随双极导联中的局部传导阻滞而改变。
窦性心律时单极电极波形与双极电极一起改变，在BrS中由尖锐和钝成分组成。然而，吡西卡尼激发后，单极导联中的凸型J点抬高持续存在，而与双极导联中的局部传导阻滞无关。这些发现提示了BrS机制的复杂性。
