Heart India

: 2017  |  Volume : 5  |  Issue : 4  |  Page : 160--162

Electrocardiogram pearl: ST-T changes in patient with chest pain – Ischemia or infarction?

Parminder Singh Manghera, Akshyaya Pradhan, Rishi Sethi 
 Department of Cardiology, King George's Medical University, Lucknow, Uttar Pradesh, India

Correspondence Address:
Akshyaya Pradhan
Department of Cardiology, King George's Medical University, Lucknow - 226 003, Uttar Pradesh


Most common electrocardiogram (ECG) findings of myocardial ischemia are ST segment deviations & T wave (ST-T) alterations. However, multiple other conditions can cause ST-T changes mimicking ischemia including ventricular hypertrophy, bundle branch block, electrolyte imbalance, drugs, channelopathies, etc. Uncommonly, incorrect placement of limb leads can also produce ST-T changes leading to diagnostic dilemma. We report a case of erroneous limb-lead placement in a 45 years male mimicking ischemic ECG changes.

How to cite this article:
Manghera PS, Pradhan A, Sethi R. Electrocardiogram pearl: ST-T changes in patient with chest pain – Ischemia or infarction?.Heart India 2017;5:160-162

How to cite this URL:
Manghera PS, Pradhan A, Sethi R. Electrocardiogram pearl: ST-T changes in patient with chest pain – Ischemia or infarction?. Heart India [serial online] 2017 [cited 2021 Mar 2 ];5:160-162
Available from: https://www.heartindia.net/text.asp?2017/5/4/160/221867

Full Text


The ST segment deviations and T wave alterations are the primary ECG abnormalities seen in myocardial ischemia or infarction. However, drugs, bundle branch blocks, ventricular hypertrophy, channelopathies, ventricular pacing and electrolyte alterations can also produce ST-T changes simulating ischemia. Not uncommonly, incorrect placement of ECG leads can produce ST segment & T wave alterations in absence of any pathology leading to diagnostic and therapeutic challenges.

 Case Report

A 45-year-old smoker, tobacco chewer male presented to the emergency department with complaint of chest heaviness and giddiness for 6 hours. On examination, his blood pressure was 176/94 mm of Hg and pulse rate of 78 beats per minute. His cardiovascular and other systemic examinations were within normal limits. His electrocardiogram (ECG) at presentation revealed ST-segment elevation with inverted T wave in leads II, III, and aVF suggestive of inferior terriorty ischemia [Figure 1]a. Owing to high index of suspicion of acute coronary syndrome, a high sensitivity cardiac troponin T (Hs-Trop T) was ordered which was <0.003 ng/ml (normal <0.014 ng/ml). Two-dimensional echocardiogram (2D-Echo) showed normal left ventricular systolic functions and absence of regional wall motion abnormality. Patients' symptoms improved with initial medical management. His subsequent ECG to our surprise was completely normal [Figure 2]. Due to this disparity between ECG changes and other supporting investigations (Hs-TropT and 2D-Echo), initial ECG was reviewed again. This time we identify the inverted P waves in inferior leads and the predominantly positive lead aVR clinching the ECG diagnosis of limb-lead reversal [Figure 1]b. Although, inverted p waves can sometimes accompany inferior ST elevation myocardial infarction due to low atrial rhythm but the positive p wave in aVR lead is not consistent with it.{Figure 1}{Figure 2}


Technical errors in ECG recording are quite common, and among them, limb-leads reversal is often encountered in clinical practice.[1] Identifying the lead reversal is important since it is estimated that 4% of all ECGs run are recorded with incorrect lead placements. The estimates are even higher for ECGs recorded in areas that necessitate a higher level of care, such as the prehospital environment.[2]

The ability to recognize ECG lead misplacement can reduce erroneous decision-making and therapy initiations. Providers should be intimately familiar with the normal morphololgy of various waves(P, QRS, T) in lead groups and the variations in baseline morphology that can be seen in each one of them. Having this information will enable a provider to make comparisons to an ECG reading in which they suspect a lead misplacement has occurred.[3] Here, we enumerate common findings and clues to identify the lead reversal [Table 1].{Table 1}


ECG lead misplacement is a common and underreported technical error. Most ECG interpretation books devote little if any space to this extremely important topic. Early and prompt recognition is imperative to avoid unnecessary, inappropriate, and harmful therapeutic interventions to the patients.[4]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.


1Rudiger A, Hellermann JP, Mukherjee R, Follath F, Turina J. Electrocardiographic artifacts due to electrode misplacement and their frequency in different clinical settings. Am J Emerg Med 2007;25:174-8.
2Batchvarov VN, Malik M, Camm AJ. Incorrect electrode cable connection during electrocardiographic recording. Europace 2007;9:1081-90.
3García-Niebla J, Llontop-García P, Valle-Racero JI, Serra-Autonell G, Batchvarov VN, de Luna AB, et al. Technical mistakes during the acquisition of the electrocardiogram. Ann Noninvasive Electrocardiol 2009;14:389-403.
4Richard L. ECG lead misplacement: A brief review of limb lead misplacement. Afr J Emerg Med 2014;4:130-9.