aVR ST Segment Elevation: Acute STEMI or Not? Incidence of an Acute Coronary Occlusion

aVR: The forgotten lead in acute coronary syndrome: A case series

Lead aVR is often considered as a neglected lead or forgotten lead owing to its reciprocal location to the lateral leads. However, it has diagnostic and prognostic importance in cases of acute coronary syndromes. We present a series of four cases of acute coronary syndrome with ST elevation (STE) in aVR and critical stenosis in coronary vessels. Patients with STE in aVR have a poor prognosis with increased morbidity not limited to increased chances of heart failure at presentation, greater hemodynamic instability, and in-hospital acute kidney injury, as well as increased mortality due to large infarction areas. Thus, early revascularization is warranted in such cases.

Look before you leap: the importance of ECG in management of out-of-hospital cardiac arrest

Graphical abstractReconstructed pre-hospital ECG, 25 mm/s 10 mm/mV.

Dogmalysis

Air medical and critical care providers encounter the extremes of being both in-hospital and out-of-hospital clinicians, work in unpredictable environments, and treat patients with the most significant injury patterns and diagnoses. These demands highlight the need to recognize unique mental challenges for those who work in the air medical environment and the process by which providers make decisions. Patients who present with a high-acuity/low-volume pathology generate particularly difficult situations with abundant opportunity for both celebrations of performance and learning from mistakes. There are times when the desired option of therapy is not available, the most appropriate destination is not feasible, or the crew is unable to address every aspect of patient care with resources that are immediately available. Although it is logical to make decisions based on anatomic and physiological knowledge, the absence of an actual answer does not necessitate the acceptance of consensus. Dogmalysis refers to the dissolution of authoritative tenets held as established opinion without adequate grounds. This article highlights the importance of dogmalysis, the value of honest scientific reflection, and the aggressive seeking of evidence-based answers as it pertains to the air medical environment.

Comparing Door-To-Balloon Time between ST-Elevation Myocardial Infarction Electrocardiogram and Its Equivalents

Background: In patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary interventions (pPCI), longer door-to-balloon (DTB) time is known to be associated with an unfavorable outcome. A percentage of patients with acute coronary occlusion present with atypical electrocardiographic (ECG) findings, known as STEMI-equivalents. We investigated whether DTB time for STEMI-equivalent patients was delayed. Methods: This is a retrospective study including patients arriving at an emergency department with the acute coronary syndrome in whom emergent pPCI was performed. ECGs were classified into STEMI and STEMI-equivalent groups. We compared DTB time, with its components, between the groups. We also investigated whether STEMI-equivalent ECG was an independent predictor of DTB time delayed for more than 90 min. Results: A total of 180 patients were included in the present study, and 23 patients (12.8%) presented with STEMI-equivalent ECGs. DTB time was significantly delayed in patients with STEMI-equivalent ECGs (89 (80–122) vs. 81 (70–88) min, p = 0.001). Multivariable logistic regression analysis showed that STEMI-equivalent ECG was an independent predictor of delayed DTB time (odds ratio: 4.692; 95% confidence interval: 1.632–13.490, p = 0.004). Conclusions: DTB time was significantly delayed in patients presenting with STEMI-equivalent ECGs. Prompt recognition of STEMI-equivalent ECGs by emergency physicians and interventional cardiologists might reduce DTB time and lead to a better clinical outcome.

Strangulation: A Cause or Mimicker of Global Myocardial Hypoxia on ECG

ST segment changes are often associated with myocardial ischemia but may be mimickers. We present a 21-year-old male who suffered a cardiac arrest following a suicide attempt by strangulation. Initial ECG revealed diffuse ST depressions and ST elevation in augmented vector right (aVR), concerning myocardial ischemia. However, repeat ECG revealed normal ST segments and an echocardiogram revealed no wall motion abnormalities. This case highlights the effects of systemic hypoxia on cardiac muscle and the need for a broad differential diagnosis when interpreting an ECG. This is invaluable when ST segment changes mimic acute myocardial infarction, but the clinical scenario suggests global hypoxia.

Distribution Characteristics of ST-Segment Elevation Myocardial Infarction and Non-ST-Segment Elevation Myocardial Infarction Culprit Lesion in Acute Myocardial Infarction Patients Based on Coronary Angiography Diagnosis

This research was aimed at exploring the application value of coronary angiography (CAG) based on a convolutional neural network algorithm in analyzing the distribution characteristics of ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) culprit lesions in acute myocardial infarction (AMI) patients. Methods. Patients with AMI treated in hospital from June 2019 to December 2020 were selected as subjects. According to the results of an echocardiogram, the patients were divided into the STEMI group (44 cases) and the NSTEMI group (36 cases). All patients received CAG. All images were denoised and edge detected by a convolutional neural network algorithm. Then, the number of diseased vessels, the location of diseased vessels, and the degree of stenosis of diseased vessels in the two groups were compared and analyzed. Results. The number of patients with complete occlusion (3 cases vs. 12 cases) and collateral circulation (5 cases vs. 20 cases) in the NSTEMI group was significantly higher than that in the STEMI group, and the difference was statistically significant, P < 0.05. There was a statistically significant difference in the number of lesions between the distal LAD (1 case vs. 10 cases) and the distal LCX (4 cases vs. 11 cases), P < 0.05. There was a statistically significant difference in the number of patients with one lesion branch (1 vs. 18) and three lesion branches (25 vs. 12) between the two groups, P < 0.05. The image quality after the convolution neural network algorithm is significantly improved, and the lesion is more prominent. Conclusion. The convolutional neural network algorithm has good performance in DSA image processing of AMI patients. STEMI and NSTEMI as the starting point of AMI disease analysis to determine the treatment plan have high clinical application value. This work provided reference and basis for the application of the convolutional neural network algorithm and CAG in the analysis of the distribution characteristics of STEMI and NSTEMI culprit lesions in AMI patients.

aVR ST-segment changes and prognosis of ST-segment elevation myocardial infarction

BACKGROUND

Clinical importance of aVR lead-related changes in predicting the prognosis of acute myocardial infarction remains uncertain. The present study aimed to assess the value of ST-segment changes in aVR lead and the outcome and sequels of the first episode of acute ST-segment elevation myocardial infarction.

METHODS

This prospective cohort study was conducted on patients suffering first episode of ST-segment elevation myocardial infarction and underwent percutaneous coronary intervention. Information was collected through hospital-recorded files reading. The electrocardiogram (ECG) was taken from the patients upon entering the hospital and followed-up for 30 days to assess cardiovascular complications.

RESULTS

In patients with anterior STEMI, with the use of multivariate analysis, admission aVR ST elevation ≥1 mm was found to be a strong and independent predictor of major cardiovascular adverse events (MACE) within 30 days of discharging (P value for trend .002). In patients with inferior (± RV) ST-segment elevation myocardial infarction (STEMI), with the use of multivariate analysis, admission aVR ST depression ≥1 mm was found to be a strong and independent predictor of MACE within 30 days of discharging (P value for trend .01).

CONCLUSION

In patients with anterior STEMI, admission aVR STE ≥1 mm was found to be a strong and independent predictor of MACE within 30 days of discharging. On the other hand, in patients with inferior STEMI, aVR ST depression ≥1 mm was found to be a strong and independent predictor of MACE within 30 days of discharging.

Incidence of cardiac interventions and associated cardiac arrest outcomes in patients with nonshockable initial rhythms and no ST elevation post resuscitation

BACKGROUND

Out of Hospital Cardiac arrest (OHCA) survivors with ST elevation (STE) with or without shockable rhythms often benefit from coronary angiography (CAG) and, if indicated, percutaneous coronary intervention (PCI). However, the benefits of CAG and PCI in OHCA survivors with nonshockable rhythms (PEA/asystole) and no STE are debated.

METHODS

Using the International Cardiac Arrest Registry (INTCAR 2.0), representing 44 centers in the US and Europe, comatose OHCA survivors with known presenting rhythms and post resuscitation ECGs were identified. Survival to hospital discharge, neurological recovery on discharge, and impact of CAG with or without PCI on such outcome were assessed and compared with other groups (shockable rhythms with or without STE).

RESULTS

Total of 2113 OHCA survivors were identified and described as; nonshockable/no STE (Nsh-NST) (n = 940, 44.5%), shockable/no STE (Sh-NST) (n = 716, 33.9%), nonshockable/STE (Nsh-ST) (n = 110, 5.2%), and shockable/STE (Sh-ST) (n = 347, 16.4%). Of Nsh-NST, 13.7% (129) were previously healthy before CA and only 17.3% (161) underwent CAG; of those, 30.4% (52) underwent PCI. A total of 18.6% (174) Nsh-NST patients survived to hospital discharge, with 57.5% (100) of such survivors having good neurological recovery (cerebral performance category 1 or 2) on discharge. Coronary angiography was associated with improved odds for survival and neurological recovery among all groups, including those with NSh-NST.

CONCLUSIONS

Nonshockable initial rhythms with no ST elevation post resuscitation was the most common presentation after OHCA. Although most of these patients did not undergo coronary angiography, among those who did, 1 in 4 patients had a culprit lesion and underwent revascularization. Invasive CAG should be at least considered for all OHCA survivors, including those with nonshockable rhythms and no ST elevation post resuscitation.

BRIEF ABSTRACT

Out of hospital cardiac arrest (OHCA) survivors with ST elevation and/or shockable rhythms benefit from coronary angiography and revascularization. Nonshockable cardiac arrest survivors with no ST elevation have the worst prognosis and rarely undergo coronary angiography. Nonshockable rhythms with no ST elevation was the most common presentation after OHCA and among a small subgroup underwent coronary angiography, 1 in 4 patients with had culprit lesion and underwent revascularization. Coronary angiography was associated with high prevalence of acute culprit coronary lesions and should be considered for those with a probably cardiac cause for their arres.

Working Against the Clock: A Model for Rural STEMI Triage

Residents in rural communities have a higher incidence of cardiac death and risk factors associated with cardiac disease. Living in a rural region can add precious time that amplifies cardiac death during an ST-elevated myocardial infarction (STEMI) episode. The consensus is that improved efficiencies can increase myocardial salvage and decrease STEMI mortality rates. This article identifies issues that may impact pre-hospital STEMI triage of patients in a rural region of the United States (U.S.). A qualitative research design was chosen to gain insight into emergency personnel perceptions of pre-hospital STEMI triage. The participants (n = 18) were obtained from a convenience sample in rural Northeast Texas, U.S. Data were gathered by individual and group semi-structured interviews. Themes were identified, synthesized, and oriented to offer a basis for understanding opportunities to improve the delivery of rural STEMI care. This study demonstrated that quality improvement initiatives aimed at achieving pre-hospital STEMI triage efficiencies have dependencies on teamwork, technology, and training in the context of 3 stages (a) pre-transport, (b) door-to-door, and (c) post-transport. A pre-hospital STEMI triage model is offered based on the findings. By incorporating this model, emergency medical coordinators in rural communities have a better opportunity to facilitate timely reperfusion therapy for this high-risk population.

A Silent Killer: Left Main Coronary Artery Disease in Gastrointestinal Bleed

Left main coronary artery disease (LMCAD) is defined as more than 50% angiographic arterial narrowing and has been demonstrated in nearly 5% of all patients undergoing coronary angiography. It carries an extremely high risk for cardiovascular morbidity and mortality as it impacts more than two-thirds of the left ventricle. Prediction of LMCAD in the right clinical setting is important for the selection of the proper treatment strategies. Typical ECG characteristics are ST elevation (STE) in lead augmented vector right (aVR-STE) of more than 0.5 mV accompanied by ST depression (STD) notably in leads I, II, and V4-6 or STE in aVR ≥ V₁. Furthermore, the presence of aVR-STE is associated with worse outcomes and careful evaluation and close monitoring are warranted. However, not every aVR-STE is an acute occlusion of the left main coronary artery (LMCA), as acute occlusion is a catastrophic event. aVR-STE can also be associated with severe triple-vessel disease or diffuse subendocardial ischemia.

STEMI Equivalents and Their Incidence during EMS Transport

Objective: The management of patients with ST-elevation myocardial infarction (STEMI) is time-critical, with a focus on early reperfusion to decrease morbidity and mortality. It is imperative that prehospital clinicians recognize STEMI early and initiate transport to hospitals capable of percutaneous coronary intervention (PCI) with a door-to-balloon time of ≤90 minutes. Three patterns have been identified as STEMI equivalents that also likely warrant prompt attention and potentially PCI: Wellens syndrome, De Winter T waves, and aVR ST elevation. The goal of our study was to assess the incidence of these findings in prehospital patients presenting with chest pain. Methods: We conducted a retrospective chart review from a large urban tertiary care emergency department. We reviewed the prehospital ECG, or ECG upon arrival, of 861 patients who were hospitalized and required cardiac catheterization between 4/10/18 and 5/7/19. Patients who had field catheterization lab activation by EMS for STEMI were excluded. If a prehospital ECG was not available for review, the first ECG obtained in the hospital was used as a proxy. Each ECG was screened for aVR elevation, De Winter T waves, and Wellens syndrome. Results: Of 278 charts with prehospital ECGs available, 12 met our criteria for STEMI equivalency (4.4%): 6 Wellens syndrome and 6 aVR STEMI. There were no cases of De Winters T waves. Of 573 charts with no prehospital ECG available, 27 had initial hospital ECGs that met our STEMI equivalent criteria (4.7%): 7 Wellens syndrome and 20 aVR STEMI. Again, there were no cases of De Winters T waves. Conclusions: These preliminary data suggest that there are significant numbers of patients whose prehospital ECG findings do not currently meet criteria for field activation of the cardiac catheterization lab, but who may require prompt catheterization. Further studies are needed to look at outcomes, but these results could support the need for further education of prehospital clinicians regarding recognition of these STEMI equivalents, as well as quality initiatives aimed at decreasing door-to-balloon time for patients with STEMI equivalents.

A Systematic Approach to Evaluate Patients Presenting With ST-Segment Elevation in Lead aVR: A Case Series

ST-segment elevation (STE) in the lead aVR indicates global ischemia of the myocardium and is often associated with obstructive coronary artery disease (CAD). We report a serial of cases presenting with STE in aVR and diffuse ST depressions in more than six other leads as a common feature, but of different etiologies, i.e., severe anemia due to gastrointestinal bleeding; drug over-dose-induced vasospasm and tachycardia, and severe CAD involving distal left main and ostial right coronary arteries, which required specific management approaches. We categorize the possible causes of STE in aVR with or without diffuse ST depression ECG according to whether anticoagulation/antithrombotic agents are indicated, contra-indicated, and propose a systematic approach in evaluating and managing these patients.

Current Controversies in Caring for the Critically Ill Pulmonary Embolism Patient

Emergency physicians must be prepared to rapidly diagnose and resuscitate patients with pulmonary embolism (PE). Certain aspects of PE resuscitation run counter to typical approaches. A specific understanding of the pathophysiology of PE is required to avoid cardiovascular collapse potentially associated with excessive intravenous fluids and positive pressure ventilation. Once PE is diagnosed, rapid risk stratification should be performed and treatment guided by patient risk class. Although anticoagulation remains the mainstay of PE treatment, emergency physicians also must understand the indications and contraindications for thrombolysis and should be aware of new therapies and models of care that may improve outcomes.

Value of ST-segment change in lead aVR in diagnosing left main disease in Non-ST-elevation acute coronary syndrome-A meta-analysis

BACKGROUND

Previous researches proved that the ST-segment elevation (STE) in lead aVR had great significance on the prediction of severe left main lesion or serious multivessel lesions. The current research is to summarize the published data and evaluate the overall association of STE in lead aVR and left main coronary artery disease (LMD) in Non-ST-elevation acute coronary syndrome.

METHODS

Literature searching was performed in the online database, and a systematic review was conducted based on the searched results. Meaningful STE in lead aVR was summarized and analyzed for odds ratio (OR) and 95% confidence intervals (95% CI).

RESULTS

Twenty-seven articles were included for final data analysis. Compared with STE < 0.05, STE ≥ 0.05 mV was associated with a higher incidence rate of LMD (OR = 6.64, 95% CI: 4.80 ~ 9.17), and the degree of STE in lead aVR was significantly associated with LMD. Myocardial infarction was more likely to occur in patients with STE ≥ 0.05 mV than in patients with STE < 0.05 mV (OR = 3.12, 95% CI: 1.73 ~ 5.62).

CONCLUSIONS

The STE in lead aVR and the degree of STE are independent predictors in diagnosing LMD or myocardial infarction.