Katragadda Silpita, Alagesan Murali, Rathakrishnan Shanmugasundaram, Kaliyaperumal Deepalakshmi, Mambatta Anith Kumar
Registrar, Department of Infectious Diseases, Apollo Health City Campus, Jubilee Hills, Hyderabad, Telangana, India.
Professor, Department of General Medicine, PSG Institute of Medical Sciences and Research, Coimbatore, Tamil Nadu, India.
J Clin Diagn Res. 2017 Jul;11(7):OC04-OC08. doi: 10.7860/JCDR/2017/26021.10155. Epub 2017 Jul 1.
Electrocardiogram (ECG) is the simplest tool for diagnosing ST Elevation Myocardial Infarction (STEMI). We can use a12 lead ECG for prognostication purposes also.
The aim of the study was to find out the role of ECG as a prognostic marker in terms of clinical outcome and wall motion abnormality.
It was a prospective study done in PSG Institute of Medical Sciences and Research, Coimbatore, Tamil Nadu, India, from January 2014 to September 2014. Patients aged above 18 years admitted with first episode of ST EMI as per the inclusion and exclusion criteria were recruited for the study. Presence of reciprocal changes and QRS amplitude was measured from ECG. Presence of Left Ventricular Dysfunction (LVD) and wall motion score were calculated from ECG along with clinical outcome during first follow up visit. Statistical analysis was done using SPSS software. Probability was calculated using chi-square test, independent t-test and ANOVA analysis.
A total of 120 patients were recruited for the study of which six were excluded based on the exclusion criteria. Among 114 patients analysed, 55 had reciprocal changes; 38 of them developed LVD which was statistically significant (p=0.002). Of the 78 patients with Anterior Wall Myocardial Infarction (AWMI), 35 had reciprocal changes; 15 (42.9%) of them had NYHA Class 1 symptoms, 14 (40%) had Class II and 4 (11%) had class III symptoms at follow up. The association was statistically significant (p=0.001). Similar statistically significant association was found in patients with Inferior Wall Myocardial Infarction (IWMI) who had reciprocal changes and NYHA symptoms at follow up (p=0.004). The mean wall motion score in patients with AWMI and reciprocal changes was 24.83 ± 4.1; whereas, without reciprocal changes was 23.98 ± 3.6; the association was not statistically significant. The mean QRS amplitude of all patients with LVD was 33.25 ±16.34. The association between QRS amplitude and LVD was not statistically significant. The overall mean wall motion score was 24.86 ± 3.91. The association between QRS amplitude and wall motion score was statistically significant (r value = 0.210). The association between QRS amplitude and wall motion score was statistically significant when we analysed AWMI (r= -0.147, p=0.199) and IWMI (r= -0.359, p=0.031) separately.
ECG can be used as a tool for prognostication in acute STEMI. The presence of reciprocal changes in the ECG can signify poorer outcome on follow up. Lower QRS amplitude can be used as a predictor of larger infarct.
心电图（ECG）是诊断ST段抬高型心肌梗死（STEMI）最简单的工具。我们也可将12导联心电图用于预后评估。
本研究的目的是探讨心电图作为预后标志物在临床结局和室壁运动异常方面的作用。
这是一项前瞻性研究，于2014年1月至2014年9月在印度泰米尔纳德邦哥印拜陀市的PSG医学科学与研究机构进行。根据纳入和排除标准，招募年龄在18岁以上、首次发作ST段抬高型心肌梗死的患者进行研究。从心电图测量有无对应性改变及QRS波振幅。在首次随访时，根据心电图计算左心室功能不全（LVD）的存在情况和室壁运动评分以及临床结局。使用SPSS软件进行统计分析。采用卡方检验、独立样本t检验和方差分析计算概率。
本研究共招募了120例患者，其中6例根据排除标准被排除。在分析的114例患者中，55例有对应性改变；其中38例发生LVD，差异有统计学意义（p = 0.002）。在78例前壁心肌梗死（AWMI）患者中，35例有对应性改变；随访时，其中15例（42.9%）有纽约心脏协会（NYHA）Ⅰ级症状，14例（40%）有Ⅱ级症状，4例（11%）有Ⅲ级症状。这种关联具有统计学意义（p = 0.001）。在有对应性改变且随访时有NYHA症状的下壁心肌梗死（IWMI）患者中也发现了类似的具有统计学意义的关联（p = 0.004）。有对应性改变的AWMI患者的平均室壁运动评分为24.83±4.1；而无对应性改变的患者为23.98±3.6；这种关联无统计学意义。所有LVD患者的平均QRS波振幅为33.25±16.34。QRS波振幅与LVD之间的关联无统计学意义。总体平均室壁运动评分为24.86±3.91。QRS波振幅与室壁运动评分之间的关联具有统计学意义（r值 = 0.210）。当我们分别分析AWMI（r = -0.147，p = 0.199）和IWMI（r = -0.359，p = 0.031）时，QRS波振幅与室壁运动评分之间的关联具有统计学意义。
心电图可作为急性STEMI预后评估的工具。心电图出现对应性改变可能预示随访时预后较差。较低的QRS波振幅可作为较大梗死灶的预测指标。
