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SummaryLead aVR was used for many purposes, but rarely for prognosis and risk assessment of NSTEMI.Risk assessment on admission is extremely valuable for patients with NSTEMI, for management strategy and optimization of resources.ECG is a very easy, rapid and applicable way of risk assessment and is of great value especially in developing countries with low resources.So, this study was designed for fulfilling the purpose of an easy way of risk assessment for ischaemic patients for better case management.Objectives of the study were:1. Exploring the potentials of ST-segment elevation in lead aVR as a prognostic sign for worse clinical outcome and in-hospital complications.2. Comparing this finding to the previously known prognostic criteria of ST-segment depression in other leads.The study consisted of 60 patients that were classified into three groups according to the elevation of ST-segment in lead aVR; no elevation, 0.05 to 0.1 mV and more than 0.1 mV.Patients must have had chest pain for more than 20 minutes with a significant rise in cardiac enzymes to be considered in these groups.All patients who had ST-segment elevation in leads other than aVR and V1, LBBB, recent PTCA (6 month), previous CABG were excluded.All patients had the following: medical history taken, clinical examination, admission ECG, cardiac enzymes level measured, recording of the clinical complications and hospital outcome, and coronary angiography done within 1 month.Main findings:Higher age groups, male gender and risk factors for coronary atherosclerosis: hypertension, diabetes mellitus, heavy smoking, dyslipidemia, and peripheral vascular disease are associated poorly with the ST-segment elevation with a P value of 0.1, 0.7, 0.7, 0.8, 0.9, 0.5 and 0.9 respectively.The elevation in lead aVR is closely associated with a higher heart rate and Killip class at presentation denoting more extensive ischaemia and cardiac muscle decompensation, the P value for each was0.003 for heart rate and 0.01 for Killip class.Killip class was the most valuable predictor of death in multivariate analysis (P value 0.001), and was even superior to lead aVR in this matter.Changes in ECG (that are well-known to be of ischaemic cause) were closely associated with a- more elevation of ST-segment in aVR, especially the number of contiguous leads showing ST-segment depression, b- the maximum depression in a single lead, c- and the sum of this depression in all leads with a very high statistical significance P value almost ≤ 0.005 for most of these criteria except for the site of ST depression where the P value is around 0.02 this was similar to other studies (Barrabes et al 2003).Other ECG changes that are less specific for coronary ischaemia such as T wave inversion, presence of right bundle branch block (RBBB), Arrhythmia, presence of left ventricular hypertrophy (LVH), and ST segment elevation in V1 were not statistically significance with elevation in lead aVR and their P values were in the same order as follows; 0.3, 0.99, 0.4, 0.8, and 0.08. This gave the newly used criteria a more sensitive meaning and intensified the debate for which criteria should be held higher during ECG analysis.In concordance with the above mentioned findings, the degree of elevation of cardiac necrosis markers CK and CK-MB was very highly associated with higher elevation in lead aVR, which was another biochemical proof of the high sensitivity and specificity of this golden ECG finding, this finding was even more evident in our study than similar studies (Barrabes et al 2003).In-hospital complications in the form of prolonged repeated anginal attacks, vitally destabilizing arrhythmia, heart failure, reinfarction and death were collectively very highly significant with the higher elevation in lead aVR with a (P value of 0.001).It was also significant with some of them individually: highly significant with reinfarction (P value 0.02), very highly significant with prolonged angina and heart failure (P value for each 0.009), but insignificant for death and arrhythmia (P value for each 0.2).However using the number of leads with ST depression as a prognostic marker was only very highly significant for the complications collectively (P value 0.001), and not significant with any of them individually, P values were: 0.5, 0.8, 0.08,0.2 and 0.5 for death, reinfarction, prolonged angina, heart failure and arrhythmias successively, no other ECG finding ”sum of, maximal ST depression and number of leads with T wave inversion could be of significance.This was another solid evidence for the importance of the new ECG marker, implying a more aggressive control of ischaemia and even invasive approach if available.A final and visual proof, angiographic survey in this study showed more angiographic lesions to be highly associated with more elevation in lead aVR, and more complex and critical lesions too, which again favors the early invasive approach, P value was 0.001, with a very highly significant positive correlation between the number of angiographic lesions and the elevation of ST-segment in lead aVR, with a (P value < 0.001).No other ECG changes that are known to be of ischaemic cause could keep the competition with all these advantages and positive correlations.The number of leads with ST depression had a P value of 0.12, and had no correlation with angiographic lesions (P value > 0.05).When the major in-hospital complications in patients with & without ST-segment depression ≥ 0.1 mV on admission were stratified for ST-segment elevation in lead aVR. The latter variable (ST elevation) was identified as a high risk subgroup, whereas the remaining patients had low complication rates irrespective of whether they had ST-segment depression in other leads or not.The currents findings illuminate the path for a new, previously neglected but easily applied and very sensitive ECG prognostic criteria.ConclusionST-segment elevation in lead aVR is a sensitive prognostic indicator in patients with NSTEMI for poor clinical outcome and more complex angiographic lesion.This indicator is a very sensitive one, even more than the widely known ST-segment depression in other leads.Our study opens the way for more research and use of ECG as an applicable tool for risk assessment, with special attention to lead aVR, the Cinderella of ECG.
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