03/29/2017

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ECG Recognition of STEMI Imposters

Kul Aggarwal, MD, MRCP, FACCProfessor of Clinical Medicine, Division of Cardiology

University of Missouri‐Columbia &

Chief, Cardiology Section, Harry S Truman VA Hospital

Normal ECG

Real STEMI characteristics

How to spot Imposters

Overview

US hospital discharges: Unstable angina/NSTEMI and STEMI

AHA. Heart Disease and Stroke Statistics–2005 Update.

STEMI = ST-elevation myocardial infarction (MI), or Q-wave MINSTEMI = non–ST-elevation MI, or non–Q-wave MI

1.67 million hospital discharges

STEMI

1.17 million discharges per year

500,000 discharges per year

Acute coronary syndromes

UA/NSTEMI

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ECG is a cornerstone in the diagnosis of STEMI• Chest pain

• ECG

• Cardiac Enzymes (biomarkers)

Confounding factors• It may be “normal”• It may show subtle abnormalities

• It may show a change from previous

• It may show pre‐existing abnormalities

• It may be “false positive”

Overview

Identification of ACS Patients in the EDPatients with the following symptoms and signs require immediate

assessment by the triage nurse for the initiation of the ACS

protocol:

Chest pain or severe epigastric pain, nontraumatic in origin, with components typical of myocardial ischemia or MI:• Central/substernal compression or crushing chest pain• Pressure, tightness, heaviness, cramping, burning, aching sensation• Unexplained indigestion, belching, epigastric pain• Radiating pain in neck, jaw, shoulders, back, or 1 or both arms

Associated dyspnea

Associated nausea/vomiting

Associated diaphoresis

If these symptoms are present, obtain stat ECG

5Adapted from the National Heart Attack Alert Program. Emergency Department: rapid identification and treatment of patients with acute myocardial infarction. US Department of Health and Human Services. US Public Health Service. National Institutes of Health. National Heart, Lung and Blood Institute; September 1993; NIH Publication No. 93-3278. Also see Table 2 of Anderson JL, et al. J Am Coll Cardiol. 2007;50:e1-e157.

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Normal ECG

ECG in AMI

Reciprocal ST depression powerful markerChange from previous ECGWidespread ST depressionIf no apparent ST depression/elevation, look for “silent” areas • Examine T waves in I, aVL• Posterior• high lateralEnsure that the date, time and demographics match!

Labs should not delay implementation of reperfusion therapy

Initial Recognition and Management

Do NOT wait for labs!!!

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Clinical context

Regionality

Clues

Reciprocal changes

Comparison

Some Key Considerations

• Could be LCx or RCA

• Could be associated with:• Posterior infarct• RV infarct

• Consider doing extra leads such as:• V4R, V5R, V6R• V7, V8, V9

Inferior STEMI

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Inferior STEMI

Anterior STEMI

Inferior STEMI

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Anterolateral STEMI

Anterior MI, recent

Inferior infarct, old

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Inf + RV MI

Acute Posterolateral STEMI

True Posterior STEMI

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Reperfusion Arrhythmia: Accelerated Idioventricular Rhythm

Early Repolarization

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Pericarditis

Patient with normal coronaries at cath; subsequent diagnosis was myocarditis

Woman with stress CM

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Tako‐Tsubo (Stress) Cardiomyopathy:Broken Heart Syndrome

Elderly gentleman with stress CM, postop radical cystectomy, blood loss

Woman with idiopathic CM (EF 20%)

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Woman with normal coronary arteries;diagnosis in this patient was HOCM

Hyperkalemia

Hyperkalemia, Severe

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Hyperklemia, Severe

Hypothermia

Pericarditis

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1st ECG in patient with hyperkalemia

Same patient as previous slide after resolution of hyperkalemia

1st ECG in patient with severe hyperkalemia

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Same patient as previous slide with improving serum K

Same patient as previous 2 slides with now normalized serum K

Ventricular pacer in patient with profound hyperkalemia

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Same patient as previous slide after resolution of hyperkalemia

1st ECG after cardiac arrest; severe acidosis pH 6.8 (negative troponin and normal serum K)

Deep T wave Inversion:Neurologic Stroke

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• Left Bundle Branch Block• Clinical context• New VsOld

• Paced rhythm

• Posterior STEMI  

Some Tough Situations

Bluetooth

Pre-Hospital ECG by EMS

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Iferior MI

Just for Fun!