There are great differences in ST-segment depression during PSVT episodes. The aim of this study is to investigate the clinical significance of ST segment depression during PSVT. The study enrolled 333 consecutive patients who were diagnosed with PSVT by electrophysiological test from Jan 1, 2021 to July 31, 2022. The range, magnitude and morphology of ST-segment depression were described. The correlation between ST-segment depression and symptoms of chest tightness, chest pain or hypotension, the correlation between ST-segment depression and coronary stenosis, and the possible influencing factors were analyzed. In addition, the diagnostic efficacy of ST-segment depression for AVRT was determined. ST-segment depression was present in 85% of patients, in 70% of which the depression range was more than six leads. The magnitude of the depression was more significant in precordial leads ( < 0.001). ST-segment depression of >1 mm in limb leads and precordial leads was found in 36.0% and 49.8% of the patients, respectively, while >3 mm was found in 2.4% and 9.6%, respectively. The morphology of ST-segment depression in limb leads was different from that in precordial leads ( < 0.001). Downsloping ST-segment depression was more common in limb leads (limb vs. precordial: 40.5% vs. 12.6%), whereas upsloping depression was more common in precordial leads (limb vs. precordial: 3.0% vs. 23.1%). Correlation analysis showed that ST-segment depression was not correlated with symptoms of chest tightness and pain, nor was it correlated with coronary artery stenosis. The most important influencing factor is the type of PSVT, especially affecting the morphology of depression in limb leads (OR = 10.27 [5.93–17.79], < 0.001). The sensitivity and specificity of downsloping ST-segment depression in limb leads for diagnosis of AVRT were 75.5% and 76.7%. ST-segment depression is a common ECG change during PSVT episodes, and it's not associated with severe coronary stenosis. The type of PSVT has a significant effect on the manifestation of ST-segment depression. The downslope morphology of ST-segment depression in limb leads is helpful in differentiating AVRT from AVNRT.

中文翻译：

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阵发性室上性心动过速ST段压低的临床意义探讨

PSVT发作期间ST段压低存在很大差异。本研究的目的是探讨 PSVT 期间 ST 段压低的临床意义。该研究连续入组了2021年1月1日至2022年7月31日期间通过电生理测试诊断为PSVT的333名患者。描述了ST段压低的范围、程度和形态。分析ST段压低与胸闷、胸痛或低血压症状的相关性，ST段压低与冠状动脉狭窄的相关性以及可能的影响因素。此外，还确定了 ST 段压低对 AVRT 的诊断功效。 85%的患者存在ST段压低，其中70%的患者压低范围超过6导联。心前导联的凹陷程度更为显着 (<0.001)。肢体导联和心前导联 ST 段压低 >1 mm 的患者分别为 36.0% 和 49.8%，而 >3 mm 的患者分别为 2.4% 和 9.6%。四肢导联 ST 段压低的形态与心前导联不同 ( < 0.001)。下斜 ST 段压低在肢体导联中更常见（肢体与心前导联：40.5% 对 12.6%），而上斜 ST 段压低在心前导联中更常见（肢体与心前导联：3.0% 对 23.1%）。相关分析显示，ST段压低与胸闷、疼痛症状无相关性，与冠状动脉狭窄也无相关性。最重要的影响因素是 PSVT 的类型，特别是影响肢体导联凹陷的形态（OR = 10.27 [5.93–17.79]，< 0.001）。肢体导联下斜 ST 段压低诊断 AVRT 的敏感性和特异性分别为 75.5% 和 76.7%。 ST 段压低是 PSVT 发作期间常见的心电图改变，并且与严重冠状动脉狭窄无关。 PSVT的类型对ST段压低的表现有显着影响。肢体导联 ST 段凹陷的下坡形态有助于区分 AVRT 和 AVNRT。