We have read with great interest the recent article entitled “J point elevation in high precordial leads associated with risk of ventricular fibrillation” by Yuki Hasegawa et al., (2020). In their case–control study, the authors compared the electrocardiogram (ECG) of 35 patients with idiopathic ventricular fibrillation (IVF) versus those of 105 age- and gender-matched control subjects and with those of 15 patients with Brugada syndrome (BrS). They evaluated the frequency of J point elevation ≥0.1 mV in the 3rd and 4th intercostal spaces. The authors concluded that the prevalence of J point elevation in the 3rd intercostal spaces was high in patients with IVF. We appreciate the authors on this successful study and would like to address some points to merit more attention.

There are conflicting results of population-based studies of J point elevation seen on surface ECG. The location of the J wave also varied in the different patient groups (Rosso et al., 2008). Importantly, this pattern can be seen in the setting of younger age, lower heart rate, electrolyte imbalance, hyperthermia (fever), and usage of pharmacological agents (antiarrhythmics, antianginals, psychotropics, or anesthetics/analgesics drugs) (Antzelevitch et al., 2017; Nam, 2012). Furthermore, the presence of the abovementioned factors in J-wave syndrome during the peri-event period can trigger the malignant arrhythmia and influence the association with sudden cardiac arrest (Priori et al., 2015). Therefore, it is necessary to include clinical data of modular factors on analysis for making clear the relationship between J point elevation in high precordial leads and ventricular fibrillation episodes. Additionally, the statistical measurement used in the study seems limited in its ability to assess relative risk. In addition, there are some methodological issues and scant data regarding skewness in the article. Especially, small sample sized make us think can be a violation of normality and so the Mann-Whitney U test could have been appropriate. Also, comparisons between IVF patients with and without J point and BrS should have been used one-way ANOVA or Kruskal-Wallis test because there are three groups (Armitage, 2008).

Conclusively,

It can be argued that J point elevation in the 3rd intercostal spaces may be a marker for “increased risk” in idiopathic ventricular fibrillation. The results could only reflect the ECG correlates of IVF but not its prognostic power for ventricular fibrillation episodes. It would be safe to say the link between J point elevation in high precordial leads and malignant arrhythmias after evaluation of the relation between the abovementioned clinical variables and ECG which was assessed by using Cox proportional hazards regression analysis in this study.

我们饶有兴趣地阅读了 Yuki Hasegawa 等人 ( 2020 )最近发表的题为“与心室颤动风险相关的心前区高导联 J 点抬高”的文章。在他们的病例对照研究中，作者比较了 35 名特发性心室颤动 (IVF) 患者与 105 名年龄和性别匹配的对照组以及 15 名 Brugada 综合征 (BrS) 患者的心电图 (ECG)。他们评估了第 3 和第 4 肋间 J 点抬高≥0.1 mV 的频率。作者得出结论，IVF 患者第三肋间隙 J 点抬高的发生率很高。我们感谢作者进行了这项成功的研究，并希望解决一些值得更多关注的问题。

在体表 ECG 上看到的 J 点抬高的基于人群的研究结果相互矛盾。J 波的位置在不同的患者组中也有所不同（Rosso 等，2008）。重要的是，这种模式可以在年龄较小、心率较低、电解质失衡、体温过高（发烧）和使用药物（抗心律失常药、抗心绞痛药、精神药物或麻醉药/镇痛药）的情况下看到（Antzelevitch 等人，2017 年；南，2012 年）。此外，在围事件期间 J 波综合征中上述因素的存在可引发恶性心律失常并影响与心脏骤停的关联（Priori et al., 2015）。因此，有必要结合模块因素的临床数据进行分析，以明确心前导联J点抬高与室颤发作之间的关系。此外，研究中使用的统计测量在评估相对风险的能力方面似乎有限。此外，文章中关于偏度的一些方法论问题和数据很少。特别是，小样本使我们认为可能违反正态性，因此 Mann-Whitney U 检验可能是合适的。此外，应该使用单向方差分析或 Kruskal-Wallis 检验来比较有和没有 J 点和 BrS 的 IVF 患者，因为有三组（Armitage，2008）。

最后，

可以争辩说，第三肋间的 J 点抬高可能是特发性心室颤动“风险增加”的标志。结果只能反映体外受精的心电图相关性，而不能反映其对心室颤动发作的预后能力。在评估上述临床变量与 ECG 之间的关系后，可以肯定地说高心前导联 J 点升高与恶性心律失常之间存在联系，ECG 在本研究中使用 Cox 比例风险回归分析进行评估。