Lim Hoon Chin Steven, Salandanan Edgar Azada, Phillips Rachel, Tan Jun Guan, Hezan Muhammad Azmi
Accident and Emergency Department, Changi General Hospital, Singapore, Singapore.
Biostatistics Department, Singapore Clinical Research Institute, Singapore, Singapore.
Emerg Med J. 2015 Oct;32(10):809-12. doi: 10.1136/emermed-2014-204102. Epub 2015 Jan 23.
Identification of the J-point and measurement of ST segment elevation at the J-point are important for the diagnosis of ST-elevation myocardial infarction (STEMI). We conducted a study to determine the inter-rater reliability (IRR) of J-point location and measurement of the magnitude of ST elevation at the J-point on ECGs of patients with STEMI by emergency department (ED) doctors.
Each participant examined 20 STEMI ECGs during a 1-month period in 2013. The participants were required to locate the J-point by selecting the small 1 mm square within which the J-point is located and measure the magnitude of ST elevation at the J-point identified (rounded up to the nearest 0.5 mm). The intraclass correlation coefficient (ICC) was calculated to assess the IRR.
Thirty doctors participated. The ICC assessing the degree to which all participants provided agreement in their assessment of the location of J-points across ECGs was 0.85 (95% CI 0.75 to 0.93), which is in the excellent range. The ICC for assessing the magnitude of ST elevation was 0.97 (95% CI 0.94 to 0.98), indicating excellent agreement as well.
ED doctors show a high level of agreement when determining the location of J-points and measuring the magnitude of ST elevation at those J-points on ECGs of patients with STEMI. The findings support the measurement of ST segment elevation at the J-point in STEMI cases and should be regarded as a consistent standard to avoid confusion.
识别J点以及测量J点处的ST段抬高对于ST段抬高型心肌梗死（STEMI）的诊断至关重要。我们开展了一项研究，以确定急诊科医生对STEMI患者心电图上J点位置的判定以及J点处ST抬高幅度测量的评分者间信度（IRR）。
2013年，每位参与者在1个月内检查20份STEMI心电图。要求参与者通过选择包含J点的1毫米见方小格来确定J点位置，并测量所确定J点处的ST抬高幅度（四舍五入至最接近的0.5毫米）。计算组内相关系数（ICC）以评估IRR。
30名医生参与。评估所有参与者对不同心电图上J点位置判定一致性程度的ICC为0.85（95%可信区间0.75至0.93），处于优秀范围。评估ST抬高幅度的ICC为0.97（95%可信区间0.94至0.98），也表明一致性极佳。
急诊科医生在确定STEMI患者心电图上J点位置以及测量这些J点处ST抬高幅度时表现出高度一致性。这些发现支持在STEMI病例中测量J点处的ST段抬高，应将其视为避免混淆的统一标准。
