J A C C : C A S E R E P O R T S V O L . 1 , N O . 4 , 2 0 1 9

ª 2 0 1 9 T H E A U T H O R S . P U B L I S H E D B Y E L S E V I E R O N B E H A L F O F T H E AM E R I C A N

C O L L E G E O F C A R D I O L O G Y F O U N DA T I O N . T H I S I S A N O P E N A C C E S S A R T I C L E U N D E R

T H E C C B Y - N C - N D L I C E N S E ( h t t p : / / c r e a t i v e c o mm o n s . o r g / l i c e n s e s / b y - n c - n d / 4 . 0 / ) .

EDITORIAL COMMENT

Electrocardiographic Diagnosis ofLife-Threatening STEMI EquivalentsWhen Every Minute Counts*

Babken Asatryan, MD, PHD, Lukas Vaisnora, MD, Negar Manavifar, MD

D espite enormous efforts implemented inthe early detection and timely treatmentof acute coronary syndromes, acute

myocardial infarction continues to be the most com-mon cause of death worldwide (1). Prompt diagnosisof acute coronary occlusion and early reperfusiontherapy are essential to reduce the morbidity andmortality in patients with ST-segment elevationmyocardial infarction (STEMI) (2). In practice, howev-er, the full spectrum of electrocardiography (ECG) ab-normalities indicating acute coronary ischemia orocclusion requiring immediate cardiac catheteriza-tion go beyond the well-known ST-segment elevationpattern.

SEE PAGE 663

In this issue of JACC: Case Reports, Plane et al. (3)describe the clinical case of a 48-year-old manadmitted with out-of-hospital cardiac arrest. Aftersuccessful resuscitation, the patient reported chestpain, and the ECG showed upsloping ST-segmentdepression (>1 mm) at the J-point, followed by tall,symmetrical T waves in precordial leads, consistentwith the de Winter syndrome. Emergency coronarycatheterization revealed an acute thrombotic occlu-sion of the proximal left anterior descending coronaryartery. This case illustrates the importance of earlyrecognition of the de Winter ECG pattern to initiatethe essential coronary catheterization.

ISSN 2666-0849

*Editorials published in JACC: Case Reports reflect the views of the

authors and do not necessarily represent the views of JACC: Case Reports

or the American College of Cardiology.

From the Department of Cardiology, Inselspital, Bern University Hospital,

Bern, Switzerland. The authors have reported that they have no

relationships relevant to the contents of this paper to disclose.

Several high-risk ECG patterns have been reportedin association with acute myocardial ischemia due tocritical stenosis or occlusion of a coronary artery.These patterns include the de Winter syndromepattern (4); isolated posterior STEMI, a challenge todiagnose with a 12-lead ECG but easy to recognizewith additional posterior leads V7 to V9; Wellenssyndrome with often evolving T-wave abnormality(signs A and B) (5); the hyperacute T waves, usuallypreceding recognizable ST-segment elevation; andthe “shark fin” sign (Figure 1). Furthermore, ECGcriteria have been proposed to identify acutemyocardial infarction with moderate-to-high proba-bility in patients with pre-existing conditions thatalter the QRS amplitude and width, as well as theJ-point and/or ST-segment on resting ECG, such asleft bundle branch block (LBBB) (6,7), right ventricu-lar paced rhythm (8), and left ventricular hypertro-phy. Integration of clinical evaluation along withserial ECGs, including assessment of previous ECGsrecorded at an asymptomatic state, often assists inoptimal decision making.

As primary percutaneous intervention (PCI) hasbeen rapidly adopted as the default reperfusionstrategy for STEMI worldwide, clearly defined criteriaare essential for accurate diagnosis and timelyreferral of patients. In current practice, ST-segmentelevation at the J-point, $1 mm in $2 adjacent leads(other than leads V2 and V3, where elevationof $2 mm in men or $1.5 mm in women is consideredsignificant) or a new LBBB is commonly used forSTEMI diagnosis (2). However, these general ECGcriteria fail to identify the STEMI equivalents.Therefore, patients with STEMI equivalents who donot present with these typical ECG changes despitehaving an acutely occluded coronary artery are morelikely to undergo a delayed revascularization

https://doi.org/10.1016/j.jaccas.2019.10.030

FIGURE 1 ECG Patterns Hinting for Potentially High-Risk Critical Coronary Artery Stenosis or Occlusion

(A) Conventional STEMI. (B to K) Potential STEMI equivalents. (I) Modification of the Sgarbossa criterion 3 by Smith et al. (7) improved the

test performance. According to the Smith-modified Sgarbossa rule, in the setting of a left bundle branch block or ventricular paced rhythm, a

cutoff value of $3 points with the 3 criteria (G to I) has 91% sensitivity and 90% specificity for STEMI. ECG ¼ electrocardiography; LVH ¼ left

ventricular hypertrophy; STEMI ¼ ST-segment elevation myocardial infarction.

J A C C : C A S E R E P O R T S , V O L . 1 , N O . 4 , 2 0 1 9 Asatryan et al.D E C E M B E R 2 0 1 9 : 6 6 6 – 8 ECG Equivalents of STEMI

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Asatryan et al. J A C C : C A S E R E P O R T S , V O L . 1 , N O . 4 , 2 0 1 9

ECG Equivalents of STEMI D E C E M B E R 2 0 1 9 : 6 6 6 – 8

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treatment. Thus, due to this under-recognition andlack of timely management, they often experience aworse clinical outcome and poor prognosis (9,10).

Although clinicians caring for patients presentingwith chest pain rely upon ECG findings as the essen-tial noninvasive test for identifying those who mightbenefit from primary PCI, their awareness of thesehigh-risk ECG patterns are pivotal in early recognitionto provide adequate treatment. However, currently,the STEMI equivalents are neither adequatelycovered in teaching curricula nor properly addressedby the current guidelines (11).

The authors certainly acknowledge that the ECG byitself is often insufficient to diagnose acute myocar-dial ischemia or infarction and that all ECG findingsshould be interpreted in the setting of clinical pre-sentation (12). However, it must be emphasized that,

as not all ST-segment elevation patterns represent a“true STEMI” (e.g., previous myocardial infarction,left ventricular hypertrophy, Takotsubo cardiomy-opathy), not all acute coronary occlusions needingprimary PCI manifest the typical ST-segment eleva-tion. Fine-tuning our recognition of this wide range ofECG patterns, hinting for potentially life-threateningcoronary stenosis or occlusion, may allow fasterdiagnosis, resulting in proper treatment andimproved patient outcomes.

ADDRESS FOR CORRESPONDENCE: Dr. BabkenAsatryan, Department of Cardiology, Inselspital, BernUniversity Hospital, Freiburgstrasse 10, 3010 Bern,Switzerland. E-mail: babken.asatryan@insel.ch.Twitter: @BabkenAsatryan.

RE F E RENCE S

1. Benjamin EJ, Muntner P, Alonso A, et al. Heartdisease and stroke statistics-2019 update: a reportfrom the American Heart Association. Circulation2019;139:e56–528.

2. O’Gara PT, Kushner FG, Ascheim DD, et al. 2013ACCF/AHA guideline for the management ofST-elevation myocardial infarction: executivesummary: a report of the American College ofCardiology Foundation/American Heart Associa-tion Task Force on Practice Guidelines. J Am CollCardiol 2013;61:485–510.

3. Plane AF, Valette X, Blanchart K, Ardouin P,Beygui F, Roule V. Occluded or not? A subtleElectrocardiographic answer. J Am Coll CardiolCase Rep 2019;1:663–5.

4. de Winter RJ, Verouden NJ, Wellens HJ,Wilde AA. Interventional cardiology group ofthe Academic Medical C. A new ECG sign ofproximal LAD occlusion. N Engl J Med 2008;359:2071–3.

5. de Zwaan C, Bar FW, Wellens HJ. Characteristicelectrocardiographic pattern indicating a criticalstenosis high in left anterior descending coronaryartery in patients admitted because of impending

myocardial infarction. Am Heart J 1982;103:730–6.

6. Sgarbossa EB, Pinski SL, Barbagelata A, et al.Electrocardiographic diagnosis of evolving acutemyocardial infarction in the presence of leftbundle-branch block. GUSTO-1 (Global Utilizationof Streptokinase and Tissue Plasminogen Activatorfor Occluded Coronary Arteries) investigators.N Engl J Med 1996;334:481–7.

7. Smith SW, Dodd KW, Henry TD, Dvorak DM,Pearce LA. Diagnosis of ST-elevation myocardialinfarction in the presence of left bundle branchblock with the ST-elevation to S-wave ratio in amodified Sgarbossa rule. Ann Emerg Med 2012;60:766–76.

8. Sgarbossa EB, Pinski SL, Gates KB, Wagner GS.Early electrocardiographic diagnosis of acutemyocardial infarction in the presence of ventricu-lar paced rhythm. GUSTO-I investigators. Am JCardiol 1996;77:423–4.

9. Pride YB, Tung P, Mohanavelu S, et al. Angio-graphic and clinical outcomes among patients withacute coronary syndromes presenting with iso-lated anterior ST-segment depression: a TRITON-

TIMI 38 (Trial to Assess Improvement in Thera-peutic Outcomes by Optimizing Platelet InhibitionWith Prasugrel-Thrombolysis In MyocardialInfarction 38) substudy. J Am Coll Cardiol Intv2010;3:806–11.

10. Daly M, Finlay D, Guldenring D, et al. Detec-tion of acute coronary occlusion in patients withacute coronary syndromes presenting with iso-lated ST-segment depression. Eur Heart J AcuteCardiovasc Care 2012;1:128–35.

11. Rokos IC, French WJ, Mattu A, et al. Appro-priate cardiac cath lab activation: optimizingelectrocardiogram interpretation and clinicaldecision-making for acute ST-elevation myocardialinfarction. Am Heart J 2010;160:995–1003.

12. Thygesen K, Alpert JS, Jaffe AS, et al. Fourthuniversal definition of myocardial infarction(2018). J Am Coll Cardiol 2018;72:2231–64.

KEY WORDS acute coronary syndrome,electrocardiogram, myocardial infarction,myocardial ischemia, percutaneous coronaryintervention