Stemi equivalents

STEMI Equivalents

Dr. Mohamed Hamouda

STEMI Equivalents

• Are those patients who do not present with this classical ECG changes but have acutely occluded coronary artery.

• They are often associated with poorer outcome and worse prognosis.

• Benefit from timely intervention

STEMI Equivalents

The common STEMI equivalents are:• 1- de Winter ST/T complex• 2- Wellens syndromes• 3- ST elevation in lead AVR• 4- LBBB with Sgarbossa criteria • 5- Isolated posterior MI • 6-T Waves upright in V1

• About 10-15% of admitted unstable angina patients

• MI occurs in about 75% within one week • The NNT for urgent catheterization to

prevent an MI is only 2.• Usually require invasive therapy, do

poorly with medical management.

+Wellens’ Syndrome

Diagnostic criteria-1. Progressive symmetrical deep T wave

inversion or biphasic T waves in leads V2- and V3

2. Little or no cardiac marker elevation3. Discrete or no ST segment elevation4. No loss of precordial R waves.5. Pattern abnormal during chest-pain free

periods

Wellens’ Syndrome

Wellens’ SyndromeWellens’ Syndrome

Wellens’ Syndrome

Type 1

ECG during and after chest pain

Type 2

Wellens’ Syndrome

Differential diagnosis• Pulmonary embolism• RBBB and RVH• LVH• HOCM• Raised intracranial pressure• Normal pediatric ECG• Persistent juvenile T wave pattern• Brugada syndrome• Hypokalemia

De winter syndrome

• Is an anterior STEMI equivalent that presents without obvious ST segment elevation.

• Is a relatively uncommon ACS (about 2% of acute LAD occlusions), but is very important to recognize.

• This syndrome is under recognized by clinicians, with consequent increased morbidity and mortality.

De winter syndrome

De winter syndromeDiagnostic criteria are: ● Upsloping ST segment depression ( > 1 mm) at the J-point seen in V2-4 ●Hyperacute T waves. The ascending limb of the T wave commencing below the isoelectric baseline.

De winter Syndrome

De winter syndrome

• de Winter's waves are probably due to severe subendocardial ischemia, with some epicardial ischemia (enough to result in hyperacute T-waves, but not enough for ST elevation.

De winter syndromeDe winter syndrome

De winter syndrome

• In contrast to Wellen's syndrome patients present with chest pain, making the presentation even more acute.

• They should have urgent angiography, (even more so than in the case of Wellen’s syndrome, who may have angiography within a day or so).

De winter syndrome

De winter syndrome

• If doubt exists about the nature of the chest pain, an echocardiogram can confirm anterior LV dyskinesia

De winter syndrome

aVR ST segment elevation and widespread ST segment depression

• ST elevation in lead aVR, with or without minor ST elevation in V1, with inferolateral ST depression is an independent marker of acute left main stem occlusion.

• The in-hospital mortality rates are very high (83 to 94%) regardless of the method of management

• Sometimes difficult to identify these patients, because the predominant clinical symptom may be catastrophic but not predominantly chest pain

• They often present with: pulmonary oedema, shock, arrhythmia or respiratory failure requiring ventilatory support.


Diagnostic criteria:•ST elevation in aVR ≥ 1mm•ST elevation in aVR ≥ V1•Widespread horizontal ST depression, most prominent in leads I, II and V4-6


Pathophysiology: • One theory suggests that there is basal

septal ischemia/infarction due to major septal branch occlusion leading to an injury current directed towards the right shoulder.

• Diffuse subendocardial ischemia producing reciprocal changes in aVR


ST elevation in aVR is not entirely specific to LMCA occlusion. It may also be seen with:

•Proximal (LAD) occlusion•Severe multi-vessel disease•Diffuse subendocardial ischaemia – e.g. due to O2 supply/demand mismatch,


In the context of widespread ST depression + symptoms of myocardial ischaemia:

•STE in aVR ≥ 1mm indicates proximal LAD / LMCA occlusion or severe 3VD•STE in aVR ≥ V1 differentiates LMCA from proximal LAD occlusion•STE in aVR ≥ 1mm predicts the need for CABG•Absence of ST elevation in aVR almost entirely excludes a significant LMCA lesion



Emergent PCI may decrease mortality to 40%

Implications for therapy in acute coronary syndromes• Patients with < 1mm STE in aVR may safely

receive clopidogrel/prasugrel as they are unlikely to proceed to urgent CABG.

• Patients with ≥ 1 mm STE in aVR may potentially require early CABG


Although only a minority of patients with AMI have LBBB their mortality is often significantly higher than that of other patients with AMI. Acute chest pain with LBBB can manifest in any of the following 3 ways:I. Commonest - LBBB but no pre-existing ECG. II. LBBB and previous ECGs do not show LBBB.III. LBBB and is known to have LBBB on old ECGs.

NEW LEFT BUNDLE BRANCH BLOCK

• New or presumably new LBBB has been considered a STEMI equivalent until AHA guidelines 2013

• New LBBB should not be considered diagnostic of acute MI in isolation


You should consider emergent PCI for LBBB in 3 situations:1) Unstable patient (hypotension, pulmonary edema, electrical instability) 2) The Sgarbossa criteria satisfied ( score ≥ 3 points)3) Smith Modified Sgarbossa Criteria Satisfied



5points 3points2points


Increased sensitivity from 20% to 90% and decreased specificity from 98 to 90%

Isolated Posterior MI

• Acute LCX occlusion often presents with isolated ST-depression ≥0.05 mV in leads V1-V3 which corresponds to acute MI of the infero-basal portion of the heart.

• Posterior chest wall leads [V7 –V9] is recommended to detect ST elevation consistent with infero-basal myocardial infarction.

• 4-7% of STEMIs present as Isolated PMI. • Inspite of the relatively small myocardial mass

necrosis the clinical consequences of PMIs are often serious and disproportionate.

• In one study by Matetzky et al MR was present in 69% of patients with isolated PMI which was moderate or severe in one third of them.

• This ECG finding should be treated as a STEMI.


ACUTE CORONARY SYNDROME - T WAVES UPRIGHT IN V1

• An upright T wave in V1 is considered an abnormal finding.

Characteristics of upright T wave in V1, which are especially significant include: ● Very Tall T waves in V1: defined as a TV1>TV6". ● New upright T wave

The causes of an upright T wave in V1 include: 1. Occasional normal finding in the elderly. 2. Incorrect lead placement. 3. LBBB 4. LVH 5. High LV voltage in young people 6. A critical proximal stenosis within : ● LAD ●LMCA ● LCX ● RCA


The following is a series or 15 -20 minutely ECGs of a 61 year old woman who presented with ongoing chest pain:


• Subsequent ECGs showed definite ST segment elevation and critical LAD stenosis was detected and stented.

Management • They should be treated as having a critical

proximal coronary artery stenosis till proven otherwise.


Stemi equivalents

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