ST depression in lead aVL differentiates inferior ST-elevation myocardial infarction from pericarditis

Beyond STEMI-NSTEMI Paradigm: Dante Pazzanese's Proposal for Occlusion Myocardial Infarction Diagnosis

Although the existing framework for classifying acute myocardial infarction (AMI) into STEMI and NSTEMI has been beneficial, it is now considered to be falling short in addressing the complexity of acute coronary syndromes. The study aims to scrutinize the current STEMI-NSTEMI paradigm and advocate for a more nuanced framework, termed as occlusion myocardial infarction (OMI) and non-occlusion myocardial infarction (NOMI), for a more accurate diagnosis and management of AMI. A comprehensive analysis of existing medical literature was conducted, with a focus on the limitations of the STEMI-NSTEMI model. The study also outlines a new diagnostic approach for patients presenting with chest pain in emergency settings. The traditional STEMI-NSTEMI model falls short in diagnostic precision and effective treatment, especially in identifying acute coronary artery occlusions. The OMI-NOMI framework offers a more anatomically and physiologically accurate model, backed by a wealth of clinical research and expert opinion. It underscores the need for quick ECG assessments and immediate reperfusion therapies for suspected OMI cases, aiming to improve patient outcomes. The OMI-NOMI framework offers a new avenue for future research and clinical application. It advocates for a more comprehensive understanding of the underlying mechanisms of acute coronary syndromes, leading to individualized treatment plans. This novel approach is expected to ignite further scholarly debate and research, particularly in the Brazilian cardiology sector, with the goal of enhancing diagnostic accuracy and treatment effectiveness in AMI patients.

ECG criteria to distinguish hypertrophic cardiomyopathy featured with "Pseudo-STEMI" from acute ST-elevation myocardial infarction

BACKGROUD

The ECG profile of Hypertrophic Cardiomyopathy (HCM) includes ST-segment elevation (STE) that may lead to misdiagnosis of acute ST-segment elevation myocardial infarction (STEMI). This pseudo-STEMI may bring non-essential treatment. We aimed to confirm the ECG differences between HCM featured with pseudo-STEMI and acute STEMI.

MATERIAL AND METHODS

We retrospectively enrolled 59 HCM cases (Group A) and 56 acute STEMI cases (Group B). Based on the locations of STE, all the patients were divided into four subgroups, including HCM with STE in anterior leads (Group A1), anterior STEMI (Group B1), HCM with STE in inferior leads (Group A2) and inferior STEMI (Group B2). Several ECG parameters were compared between these subgroups.

RESULTS

ECG parameters significantly differed between these groups, especially the number of leads with TWI. We evaluated the diagnostic value of ECG profiles for those groups. ROC analysis showed that for Group A vs. Group B, number of leads with TWI showed the highest AUC value of 0.805 and its cutoff of 2.5, with 76.3% sensitivity and 76.8% specificity. For Group A1 vs. Group B1, it showed the highest AUC value of 0.801 and its cut-off point was 2.5, with 77.1% sensitivity and 79.1% specificity. For Group A2 vs. Group B2, it showed the highest AUC value of 0.822 and the cut-off value was 4.5, with 54.5% sensitivity and 92.3% specificity.

CONCLUSION

ECG plays a valid tool to distinguish "Pseudo-STEMI" HCM from acute STEMI, especially number of leads with TWI.

Inferior Subtle ST Elevation. Would You Activate Cardiac Catheterization Laboratory?

BACKGROUND

According to guidelines, patients with inferior myocardial infarction only qualify for emergent reperfusion if they have at least 1 mm of ST elevation in two contiguous inferior leads. Although this has remained the standard for years, acute coronary occlusion may occur in patients with nondiagnostic ST elevation. Accordingly, a paradigm change is instigated, shifting the focus to physiopathology (occlusion myocardial infarction) rather than ST criteria.

CASE REPORT

A middle-aged man presented to our emergency department with chest pain and subtle nondiagnostic electrocardiography (ECG) changes in inferior leads. A careful examination of aVL to detect ST depression in this lead was the key to successfully diagnosing occlusion myocardial infarction, allowing early revascularization of an occluded right coronary artery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Accurate diagnosis of coronary occlusion by means of ECG can be challenging in certain situations, as acute myocardial ischemia may occur in patients with nondiagnostic ST elevation, especially in the inferior leads. A thorough examination of aVL searching for ST depression is essential in these situations.

[STEMI mimics : ST elevations on ECG: alternative diagnoses to acute coronary occlusion]

BACKGROUND

The electrocardiogram (ECG) is an integral part of basic emergency medical diagnosis and preoperative evaluation. In cases of ST elevation myocardial infarction (STEMI) immediate treatment is mandatory after correlation of ischemic symptoms with the ECG pattern. However, there are also ECG patterns that can imitate STEMI, possibly resulting in the true underlying diagnosis being missed and inappropriate therapy being initiated.

OBJECTIVES

This paper provides an overview of the most important diagnoses that can imitate STEMI on ECG.

MATERIAL AND METHODS

A literature search was carried out to determine the most important differential diagnoses of ST elevation on ECG. These STEMI mimics are discussed in detail and their relevance for emergency medicine is explained.

RESULTS

This article provides an overview of differential diagnoses that should be known in emergency medicine when assessing an ECG with ST elevations.

CONCLUSION

Good knowledge of the ECG patterns presented here can support decision-making in emergency medicine.

Electrocardiogram evolution of acute anterior ST-segment elevation myocardial infarction following pericarditis

Electrocardiogram is a powerful tool for differentiating acute ST‐segment elevation myocardial infarction (STEMI) and pericarditis. However, an unusual ECG presentation of the simultaneous occurrence of the two conditions has not been reported previously. In this article, we report a case of ECG evolution of acute anterior STEMI following pericarditis with pericardial effusion (PE) and find that QRS complex widening in ECG lead with maximal ST‐segment elevation is also applicable for identifying STEMI even in patients with prior pericarditis. Undoubtedly, our case can help prevent emergency physicians from making incorrect diagnoses and administering inappropriate treatments.

Sharing and Teaching Electrocardiograms to Minimize Infarction (STEMI): reducing diagnostic time for acute coronary occlusion in the emergency department

BACKGROUND

Limits to ST-Elevation Myocardial Infarction (STEMI) criteria may lead to prolonged diagnostic time for acute coronary occlusion. We aimed to reduce ECG-to-Activation (ETA) time through audit and feedback on STEMI-equivalents and subtle occlusions, without increasing Code STEMIs without culprit lesions.

METHODS

This multi-centre, quality improvement initiative reviewed all Code STEMI patients from the emergency department (ED) over a one-year baseline and one-year intervention period. We measured ETA time, from the first ED ECG to the time a Code STEMI was activated. Our intervention strategy involved a grand rounds presentation and an internal website presenting weekly local challenging cases, along with literature on STEMI-equivalents and subtle occlusions. Our outcome measure was ETA time for culprit lesions, our process measure was website views/visits, and our balancing measure was the percentage of Code STEMIs without culprit lesions.

RESULTS

There were 51 culprit lesions in the baseline period, and 64 in the intervention period. Median ETA declined from 28.0 min (95% confidence interval [CI] 15.0-45.0) to 8.0 min (95%CI 6.0-15.0). The website garnered 70.4 views/week and 27.7 visitors/week in a group of 80 physicians. There was no change in percentage of Code STEMIs without culprit lesions: 28.2% (95%CI 17.8-38.6) to 20.0% (95%CI 11.2-28.8%). Conclusions Our novel weekly web-based feedback to all emergency physicians was associated with a reduction in ETA time by 20 min, without increasing Code STEMIs without culprit lesions. Local ECG audit and feedback, guided by ETA as a quality metric for acute coronary occlusion, could be replicated in other settings to improve care.

[High-risk ECGs in acute chest pain : Signs of acute ischemia beyond STEMI]

BACKGROUND

Obtaining an electrocardiogram (ECG) is the gold standard for initial diagnostics of atraumatic chest pain. To provide optimal patient care, the treating physician has to be proficient in recognizing early signs of myocardial ischemia. Information from the clinical assessment and typical ECG signs have to be recognized promptly in order to diagnose myocardial ischemia early.

METHODS

A selective literature search in international databases (PubMed, Cochrane Library, Google Scholar) was conducted; current, topic-specific websites and literature were also included and evaluated.

RESULTS

Several subtle ECG abnormalities exist besides the typical ST-elevation myocardial infarction (STEMI) and well-known STEMI equivalents and may point to possible myocardial ischemia.

DISCUSSION

To fully evaluate the ECG in patients with atraumatic chest pain, typical signs of ischemia like STEMI as well as subtle ECG signs should be recognized to allow early cardiac intervention.

STEMI: A transitional fossil in MI classification?

An important task in emergency cardiology is distinguishing patients with acute coronary occlusion (ACO), who will benefit from emergent reperfusion therapy, from those without ongoing myocyte loss who can be managed with medical therapy and for whom potentially harmful invasive interventions can be deferred. The electrocardiogram is critical in this process. Although the ST-segment elevation myocardial infarction (STEMI)/non-STEMI paradigm is well-established, with "STEMI" representing ACO, its evidence base is poor, and this can have dire consequences. The universally recommended STEMI criteria do not accurately diagnose ACO; in fact, they miss more than one-fourth of the patients with ACO, and also result in a substantial burden of unnecessary catheterization laboratory activations. We here discuss why we believe it is time to change the current STEMI/non-STEMI paradigm.

Low diagnostic yield of ST elevation myocardial infarction amplitude criteria in chest pain patients at the emergency department

OBJECTIVES

To evaluate the diagnostic yield of the ECG criteria for ST-elevation myocardial infarction in a large cohort of emergency department chest pain patients, and to determine whether extended ECG criteria or reciprocal ST depression can improve accuracy. Design: Observational, register-based diagnostic study on the accuracy of ECG criteria for ST-elevation myocardial infarction. Between Jan 2010 and Dec 2014 all patients aged ≥30 years with chest pain who had an ECG recorded within 4 h at two emergency departments in Sweden were included. Exclusion criteria were: ECG with poor technical quality; QRS duration ≥120 ms; ECG signs of left ventricular hypertrophy; or previous coronary artery bypass surgery. Conventional and extended ECG criteria were applied to all patients. The main outcome was acute myocardial infarction (AMI) and an occluded/near-occluded coronary artery at angiography. Results: Finally, 19932 patients were included. Conventional ECG criteria for ST elevation myocardial infarction were fulfilled in 502 patients, and extended criteria in 1249 patients. Sensitivity for conventional ECG criteria in diagnosing AMI with coronary occlusion/near-occlusion was 17%, specificity 98% and positive predictive value 12%. Corresponding data for extended ECG criteria were 30%, 94% and 8%. When reciprocal ST depression was added to the criteria, the positive predictive value rose to 24% for the conventional and 23% for the extended criteria. Conclusions: In unselected chest pain patients at the emergency department, the diagnostic yield of both conventional and extended ECG criteria for ST-elevation myocardial infarction is low. The PPV can be increased by also considering reciprocal ST depression.

DIagnostic accuracy oF electrocardiogram for acute coronary OCClUsion resuLTing in myocardial infarction (DIFOCCULT Study)

Background

Although ST-segment elevation (STE) has been used synonymously with acute coronary occlusion (ACO), current STE criteria miss nearly one-third of ACO and result in a substantial amount of false catheterization laboratory activations. As many other electrocardiographic (ECG) findings can reliably indicate ACO, we sought whether a new ACO/non-ACO myocardial infarction (MI) paradigm would result in better identification of the patients who need acute reperfusion therapy.

Methods

A total of 3000 patients were enrolled in STEMI, non-STEMI and control groups. All ECGs were reviewed by two cardiologists, blinded to any outcomes, for the current STEMI criteria and other subtle signs. A combined ACO endpoint was composed of peak troponin level, troponin rise within the first 24 h and angiographic appearance. The dead or alive status was checked from hospital records and from the electronic national database.

Results

In non-STEMI group, 28.2% of the patients were re-classified by the ECG reviewers as having ACO. This subgroup had a higher frequency of ACO, myocardial damage, and both in-hospital and long-term mortality compared to non-STEMI group. A prospective ACOMI/non-ACOMI approach to the ECG had superior diagnostic accuracy compared to the STE/non-STEMI approach in the prediction of ACO and long-term mortality. In Cox-regression analysis early intervention in patients with non-ACO-predicting ECGs was associated with a higher long-term mortality.

Conclusions

We believe that it is time for a new paradigm shift from the STEMI/non-STEMI to the ACOMI/non-ACOMI in the acute management of MI. (DIFOCCULT study; ClinicalTrials.gov number, NCT04022668.).

ST Segment Elevation Caused by Artifact From Cylindrical Battery Ingestion

BACKGROUND

Ingestion of cylindrical batteries is uncommon. Management can include removal via upper endoscopy, surgical excision, or observation. This case demonstrates the rare phenomenon of cylindrical battery ingestion causing an electrocardiogram (ECG) artifact that mimics ST segment myocardial infarction (STEMI).

CASE REPORT

A 51-year-old man who ingested 13 small pencils and 18 AA batteries was found to have ST segment elevation in the inferior leads of the ECG. Further cardiac workup including cardiac biomarkers and transthoracic echocardiogram was negative, and his ECG changes resolved after extraction of the batteries. The ST segment changes were most likely caused by electrical artifact from battery ingestion. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: When faced with an ECG finding that is unexpected and that does not fit the patient's overall clinical picture, emergency physicians should consider artifact as a possible cause. Recognition of artifact as the cause of an ECG abnormality can obviate the need for a prolonged and potentially invasive cardiac workup.

Optimal measuring point for ST deviation in chest pain patients with possible acute coronary syndrome

INTRODUCTION

In the ECG, significant ST elevation or depression according to specific amplitude criteria can be indicative of acute coronary syndrome (ACS). Guidelines state that the ST amplitude should be measured at the J point, but data to support that this is the optimal measuring point for ACS detection is lacking. We evaluated the impact of different measuring points for ST deviation on the diagnostic accuracy for ACS in unselected emergency department (ED) chest pain patients.

MATERIAL AND METHODS

We included 14,148 adult patients with acute chest pain and an ECG recorded at a Swedish ED between 2010 and 2014. ST deviation was measured at the J point (STJ) and at 20, 40, 60 and 80 ms after the J point. A discharge diagnosis of ACS or not at the index visit was noted in all patients.

RESULTS

In total, 1489 (10.5%) patients had ACS. ST amplitude criteria at STJ had a sensitivity of 28% and a specificity of 92% for ACS. With these criteria, the highest positive and negative predictive values for ACS were obtained near the J point, but the optimal point varied with ST deviation, age group and sex. The overall best measuring points were STJ and ST20.

CONCLUSIONS

This study indicates that the diagnostic accuracy of the ECG criteria for ACS is very low in ED chest pain patients, and that the optimal measuring point for the ST amplitude in the detection of ACS differs between ST elevation and depression, and between patient subgroups.

Electrocardiographic changes in the differentiation of ischemic and non-ischemic ST elevation

Identification of true STEMI among patients with different ST-elevation etiology may be improved by considering reciprocal ST depression, ST depression in aVR and chest-lead PR depression.

What is the Significance of Elevated Troponin I in Children and Adolescents? A Diagnostic Approach

Troponin is a marker that displays cardiac injury quickly and accurately. In adults, troponin elevation is usually associated with coronary artery disease and requires urgent cardiac catheterization. In healthy children, myocardial injury is rare and may develop due to many different causes. Therefore, troponin elevation in children and adolescents does not usually require emergency cardiac catheterization. The aim of this study is to assess the most common causes of troponin elevation in children and adolescents and to show which diagnostic tests are helpful in assessing pediatric patients with elevated troponin. Patients who had been diagnosed with troponin I elevation (> 0.06 ng/ml) at Dr. Sami Ulus Maternity, Children's Health and Disease Training and Research Hospital between 2007 and 2018 were retrospectively evaluated. Patients undergoing cardiac surgery and those with severe congenital heart disease were excluded from the study. The medical records of the patients were examined and age, gender, diagnostic tests, and diagnosis were evaluated. During the study period, the records of 972 patients were obtained. 213 patients were excluded from the study because of heart surgery, congenital heart disease, and neonatal asphyxia or sepsis. Of the remaining 759 patients, 58% were male, 42% were female, and the median age was 4 years (3 days to 17 years). The most frequent causes are myopericarditis (n: 164), drug intoxications (n: 85), carbon monoxide poisoning (n: 74), perimyocarditis (n: 65), and intensive inhalation β agonist use in acute asthma and lower respiratory tract infections (n: 70). Patients diagnosed with myocarditis and myopericarditis were admitted with a complaint of chest pain, and the diagnosis was made by history, physical examination, ECG, and echocardiographic findings. Unlike adults, troponin I elevation may be associated with many cardiac and non-cardiac pathologies in children. The most common pathologies in cardiac etiology are myopericarditis and perimyocarditis and can be diagnosed by history, physical examination, ECG, and echocardiography. Cardiac catheterization is not necessary except for rare cardiac pathologies and does not alter the prognosis.

Why complicate an important task? An orderly display of the limb leads in the 12-lead electrocardiogram and its implications for recognition of acute coronary syndrome

Background

In the standard ECG display, limb leads are presented in a non-anatomical sequence: I, II, III, aVR, aVL, aVF. The Cabrera system is a display format which instead presents the limb leads in a cranial/left-to-caudal/right sequence, i.e. in an anatomically sequential order. Lead aVR is replaced in the Cabrera display by its inverted version, −aVR, which is presented in its logical place between lead I and lead II.

Main text

In this debate article possible implications of using the Cabrera display, instead of the standard, non-contiguous lead display, are presented, focusing on its use in patients with possible acute coronary syndrome. The importance of appreciating reciprocal limb-lead ECG changes and the diagnostic and prognostic value of including aVR or lead −aVR in ECG interpretation in acute coronary syndrome is covered. Illustrative cases and ECGs are presented with both the standard and contiguous limb lead display for each ECG.

A contiguous lead display is useful when diagnosing acute coronary syndrome in at least 3 ways: 1) when contiguous leads are present adjacent to each other, identification of ST elevation in two contiguous leads is simple; 2) a contiguous lead display facilitates understanding of lead relationships as well as reciprocal changes; 3) it makes the common neglect of lead aVR unlikely.

Conlusions

It is logical to display the limb leads in their sequential anatomical order and it may have advantages both in diagnostics and ECG learning.

In inferior myocardial infarction, neither ST elevation in lead V1 nor ST depression in lead I are reliable findings for the diagnosis of right ventricular infarction

OBJECTIVE

In the presence of inferior myocardial infarction (MI), ST depression (STD) in lead I has been claimed to be accurate for diagnosis of right ventricular (RV) MI. We sought to evaluate this claim and also whether ST Elevation (STE) in lead V1 would be helpful, with or without STD in V2.

METHODS

Retrospective study of consecutive inferior STEMI, comparing ECGs of patients with, to those without, RVMI, as determined by angiographic coronary occlusion proximal to the RV marginal branch. STE and STD were measured at the J-point, relative to the PQ junction. The primary outcomes were sensitivity/specificity of 1) STD in lead I ≥ 0.5 mm and 2) STE in lead V1 ≥ 0.5 mm, stratified by presence or absence of posterior (inferobasal) MI, as determined by ≥0.5 mm STD in lead V2, for differentiating RVMI from non-RVMI.

RESULTS

Of 149 patients with inferior STEMI, 43 (29%) had RVMI and 106 (71%) did not. There was no difference in the presence or absence of at least 0.5 mm STD in Lead I between patients with (37/43, 86%) vs. without RVMI (85/106, 80%, p = 0.56). In those with, vs. without, RVMI, (15/43, 35%) had STE in V1, versus (17/106, 16%) (p = 0.015). Specificity of STE in V1 for RVMI was 84%; sensitivity was 35%. Sensitivity was higher without (69%), than with (35%), STD in V2.

CONCLUSION

Among inferior STEMI, the presence of any ST depression in lead I does not help to diagnose RVMI. ST elevation ≥0.5 mm in lead V1 is specific for RVMI, and moderately sensitive only if concomitant STD ≥ 0.5 mm in V2 is not present. Although STE in V1 is quite specific, overall the diagnostic characteristics of the standard 12‑lead ECG are inadequate to definitively diagnose, or exclude, RVMI, as defined angiographically.

Case report: Apical variant hypertrophic cardiomyopathy simulating an acute inferior myocardial infarction

We present a female patient who arrived to the emergency department with chest pain without known medical history at the time of consultation. Considering her risk factors and electrocardiographic findings, it was decided to perform a coronary catheterization under the suspicion of acute myocardial infarction. The catheterization and another studies was negative for coronary artery disease. Additional studies were conclusive for apical variant hypertrophic cardiomyopathy or Yamaguchi syndrome.

Acute Myopericardial Syndromes

Acute myopericardial syndromes are common but can be challenging to manage and potentially have life-threatening complications. Careful clinical history, physical examination, electrocardiogram interpretation, and application of diagnostic criteria are needed to make an accurate diagnosis, exclude concomitant disease, and properly treat patients. Therapy for acute pericarditis should be guided per the underlying cause. For the most common causes, nonsteroidal antiinflammatory drugs or aspirin with the addition of colchicine remains the mainstay of therapy. Patients with hemodynamic compromise who are resistant to therapy or display high-risk features should prompt hospitalization and initiation of more aggressive and/or invasive therapy.

New Insights Into the Use of the 12-Lead Electrocardiogram for Diagnosing Acute Myocardial Infarction in the Emergency Department

The 12-lead electrocardiogram (ECG) remains the most immediately accessible and widely used initial diagnostic tool for guiding management in patients with suspected myocardial infarction (MI). Although the development of high-sensitivity cardiac troponin assays has improved the rule-in and rule-out and risk stratification of acute MI without ST elevation, the immediate management of the subset of acute MI with acute coronary occlusion depends on integrating clinical presentation and ECG findings. Careful interpretation of the ECG might yield subtle features suggestive of ischemia that might facilitate more rapid triage of patients with subtle acute coronary occlusion or, conversely, in identification of ST-elevation MI mimics (pseudo ST-elevation MI patterns). Our goal in this review article is to consider recent advances in the use of the ECG to diagnose coronary occlusion MIs, including the application of rules that allow MI to be diagnosed on the basis of atypical ECG manifestations. Such rules include the modified Sgarbossa criteria allowing identification of acute MI in left bundle branch block or ventricular pacing, the 3- and 4-variable formula to differentiate normal ST elevation (formerly called early repolarization) from subtle ECG signs of left anterior descending coronary artery occlusion, the differentiation of ST elevation of left ventricular aneurysm from that of acute anterior MI, and the use of lead aVL in the recognition of inferior MI. Improved use of the ECG is essential to improving the diagnosis and appropriate early management of acute coronary occlusion MIs, which will lead to improved outcomes for patients who present with acute coronary syndrome.