ST Segment Elevation in Conditions ST Segment Elevation in Conditions Other Than Acute Myocardial Other Than Acute Myocardial

InfarctionInfarction

Bobby Dery MDDepartment of Emergency Medicine

St. Mary’s Hospital

Grand Junction, CO

GoalsGoals• Review several general principles of EKG interpretation.

• Cover the common causes of ST elevation other than ischemia.

• Briefly review a few of the less common, perhaps esoteric, causes of ST elevation.

• Leave you more comfortable differentiating the various causes of ST elevation.

• Avoid putting you to sleep.

SignificanceSignificance• AMI is often represented on the EKG by ST-segment elevation.

• Reperfusion therapy has proven beneficial in these infarctions.

• The earlier the reperfusion, the greater the benefit.

• In fact, time to reperfusion is now a closely monitored measure of quality of care.

• However, AMI is not the only source of ST-segment elevation on the EKG…

SignificanceSignificance

• J Emerg Med 1998: 171/202 (85%) ED pts. with CP and ST elevation with dx other than MI.

• Ann Emerg Med 1994: 63/123 (51%) with CP and ST elevation with dx other than MI.

• Am J Cardiol 1994: 10/93 (11%) of pts. receiving thrombolytics did not have AMI.

• Ann Emerg Med 1996: 35/609 (6%) of pts. receiving thrombolytics did not have AMI.

Diagnosis:Diagnosis:

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1. Left Bundle Branch Block

2. Early Repolarization

3. Acute Myocardial Infarction

Early repol 1Early repol 1

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Diagnosis:Diagnosis: Early ReoplarizationEarly Reoplarization

““Early Repolarization”Early Repolarization”

• A misnomer.

• A normal variant; seen mostly in young, healthy.

• Typical Features: - 1-4mm in mid-precordial leads- greatest elevation at V4- J-point notching common- tall T waves without inversion- concave up ST segment (“smiley”)- PR depressionearly repol of atrial tissue

Early repol againEarly repol againEarly ReoplarizationEarly Reoplarization

Male PatternMale PatternDiagnosis:Diagnosis:

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J Am Coll Cardiol 2002;40:1870-76J Am Coll Cardiol 2002;40:1870-76Surawicz et alSurawicz et al

Female Male

J Am Coll CardiolJ Am Coll CardiolMale

The Male PatternThe Male Pattern

• So prevalent it is a normal finding, not a normal variant.

- 1960 Am J Cardiol: 6014 healthy males (USAF). 91% with 1-3 mm elevation; greatest in V2.

- 2002 J Am Coll Cardiol: 529 males. 91% with >1 mm elevation V1-V4 among 17-24 y/o.

• Incidence of ST elevation declines with age. Only 30% of men 76 years or older display this pattern.

• Elevation of 1-3 mm. Most marked in V2. Concave up.

Male PatternMale Pattern

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Diagnosis:Diagnosis:

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• • Some young men.Some young men.• • Combination of early repol and juvenile T-wave?Combination of early repol and juvenile T-wave?• “• “Very suggestive of AMI”.Very suggestive of AMI”.

Normal Variant!!Normal Variant!!

8 m/o with juvenile T wave pattern8 m/o with juvenile T wave pattern

Juvenile T WavesJuvenile T Waves

• The T wave vector may be directed posteriorly in young children, resulting in an inverted T wave over right precordium.

• This vector usually becomes anterior with age. By age 10 most with upright T wave axis in V1-3.

• T waves may remain inverted in a minority of adultscalled the Persistent T Wave Pattern.

• Combine this with some ST elevation from early repolarization and you get a concerning shape!

Nl variants summaryNl variants summary

MaleMalePatternPattern

EarlyEarlyRepol.Repol.

PersistentPersistent

T waveT wavePatternPattern

Normal and normal variantsNormal and normal variants

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Diagnosis:Diagnosis: LBBBLBBB

LBBBLBBB

• Understand the EKG concept of “primary” and “secondary” ST changes.

• In general, the deeper the S wave, the greater the ST segment elevation. (i.e. secondary ST change.)

• LBBB classically has deep S waves in right sided pre-cordial leads ST elevations in these leads.

• This phenomena makes diagnosing antero-septal ischemia difficult in the presence of a LBBB.

Diagnosis:Diagnosis: LBBBLBBB

Diagnosis:Diagnosis:

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1. Left Ventricular Hypertrophy

2. Hyperkalemia

3. Pericarditis

Diagnosis:Diagnosis: LVHLVH

LVHLVH

• Again we see the deeper the S wave the greater the ST elevation…similar concept as with LBBB.

• LVH is one of the most common conditions mistaken for AMI.

• Elevated ST segments with LVH tend to be in V1 and V2 only.

• Elevated ST segments with LVH tend to be concave up; in distinction to the ST segments in AMI.

Diagnosis:Diagnosis: LVHLVH

PericarditisPericarditisDiagnosis:Diagnosis:

PericarditisPericarditis

• Diffuse ST elevation in pre-cordial and limb leads: it would be rare for MI to do this.

• Typically a diffuse process, which affects the atria as well PR depression = atrial current of injury.

• Notice: aVR is a contrarian! (ST ; PR)

• ST segments usually “smiley”; < 5mm of elevation.

• These EKG findings are variably present, as pericarditis has several stages.

PericarditisPericarditisDiagnosis:Diagnosis:

Diagnosis:Diagnosis:

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1. Septal Myocardial Infaction

2. Hyperkalemia

3. Brugada Syndrome

Brugada SyndromeBrugada SyndromeDiagnosis:Diagnosis:

• First described in 1992 by Josep and Pedro Brugada. (see AJEM 3/03)

• Believed due to a Na channel defect in epicardium, but not in endocardium of RV.

• Structurally normal heart.

• Predisposes to VT and VF. (think syncope).

• Believed to account for 40-60% of cases of idiopathic V-fib!

Brugada SyndromeBrugada SyndromeEKG

• Complete or incomplete RBBB pattern.

• ST segment elevation in V1 and V2.

• ST segment begins from top of R’ wave, is downsloping, and ends with an inverted T wave.

V1 Brugada V1 Hyper K V1 PE

Brugada SyndromeBrugada SyndromeDiagnosis:Diagnosis:

HyperkalemiaHyperkalemiaDiagnosis:Diagnosis:

HyperkalemiaHyperkalemia

• Tall, symmetric, peaked T waves (K 5’s)

• QRS prolongation (K 6’s)

• Loss of P wave amplitudeThe scaffold I use to remember these changes is that they begin at the T wave and progress backwards through the

EKG complex as serum K rises.

• “Dialysible current of injury”, aka pseudo-infarction pattern

• Sine wavedeath.

HyperkalemiaHyperkalemiaDiagnosis:Diagnosis:

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Anterior Septal MIAnterior Septal MIDiagnosis:Diagnosis:

Anterior Septal MIAnterior Septal MIDiagnosis:Diagnosis:

Inferior MIInferior MIDiagnosis:Diagnosis:

Ventricular AneurysmVentricular AneurysmDiagnosis:Diagnosis:

Ventricular AneurysmVentricular Aneurysm

• Complication of AMI.

• Persistent ST elevation weeks to months after extensive MI indicates ventricular aneurysm.

• Caused by fibrosis of necrotic myocardium following transmural infarction.

• Can present as HF, arrhythmia, embolus.

• Aneurysectomy.

Summary ThoughtsSummary Thoughts

• This is an important differential, and some of the differences are subtle.

• The most common causes of ST elevation mistaken for ACS in multiple studies were: LVH, early repolarization, BBB and ventricular aneurysm.

• In developing a differential consider: shape of the ST segment, leads involved, other features of the EKG, and the general clinical picture.

Summary Thoughts...Summary Thoughts...

• I put the diagnoses in groups to aid memorization:

1) Three Normal Variants: male pattern, early repol, juvenile T wave pattern.

2) Two Secondary ST changes: LVH, LBBB

3) Two with weird, downsloping ST: Brugada Syndrome, hyper K

4) Pericarditis: Diffuse- it’s own catagory

5) ACS and ventricular aneurysm:

6) Other: PE, cardioversion,

CME QuizCME Quiz

Diagnosis:Diagnosis:

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1. Left Ventricular Hypertrophy

2. Early Repolarization

3. Acute Myocardial Infarction

Diagnosis:Diagnosis:

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1. Left Ventricular Hypertrophy

2. Hyperkalemia

3. Pericarditis

Diagnosis:Diagnosis:

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Hyp

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1. Septal Myocardial Infaction

2. Hyperkalemia

3. Brugada Syndrome

Suggested ReadingSuggested Reading

• Wang et al. N Engl J Med 2003, 349:22

• J Am Coll Cardio 2002;40:1870-6

• Ann Emerg Med 1994; 23:17-24

• J Emerg Med 1998;16:797-8

• Am J Emerg Med; March, 2003

• Uptodate.com

• Am J Cardiol 1960; 6:200-31

No masNo mas

CME QuizCME Quiz

EKG DreamingEKG Dreaming

ST Segment Elevation in Conditions ST Segment Elevation in Conditions Other Than Acute Myocardial Other Than Acute Myocardial

InfarctionInfarction

B. DeryColorado West Emergency PhysiciansGrand Junction, CO

Lastly…Lastly…

DCDCCardio-Cardio-versionversion

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NEJM tracingsNEJM tracings

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N Engl J Med 2003;349:2128-2135. Wang K et al

Lvh2-skipLvh2-skip

Lbbb-skipLbbb-skip

Lbbb2-skipLbbb2-skip

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Persistent juvenile patternPersistent juvenile pattern