1. ST ELEVATION
Jason Mitchell, PGY2
July 15, 2010

2. Context CP and ST Elevation common ED presentation
Correct ECG interpretation impacts management decisions and patient outcome
Certain patients with CP and ST elevation require rapid intervention via thombolysis or PCI
Misdiagnosis potentially harmful

3. Context 1996 ACC/AHA Class I Recommendation for Thrombolysis
“ST elevation greater than 0.1 mV in two or more contiguous leads.”1
1 Ryan TJ, Anderson JL, Antman EM, et al. ACC/AHA guidelines for the management of patients with acute myocardial infarction. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Acute Myocardial Infarction). .J Am Coll Cardiol Nov 1;28(5):

4. Context
Disorders with ST Elevation Meeting ACC/AHA Thrombolysis Guideline
Acute Myocardial Infarction
Early Repolarization
Left Ventricular Hypertrophy
Left Ventricular Aneurysm
Left Bundle Branch Block
Ventricular Paced Rhythm
Hypothermia (Osborn Waves)
Hyperkalemia
Brugada Syndrome
Pulmonary Embolism
Acute Cerebral Hemorrhage
WPW

5. Context 2000 ACEP Qualifier
“ST-segment elevations greater than 0.1 mV in 2 or more contiguous leads that are not characteristic of early repolarization or pericarditis, nor of a repolarization abnormality from LVH or BBB in patients with clinical presentation suggestive of AMI.”2
2 Critical issues in the evaluation and management of adult patients presenting with suspected acute myocardial infarction or unstable angina. Ann Emerg Med 2000;35:

6. ST Morphology

7. ST Morphology
Concave Up vs. Concave Down

8. ST Morphology
Concave Up vs. Concave Down

9. ST Segment Elevation
Differentiating STEMI from other ST Elevation Syndromes
Dynamic ECG changes
Reciprocal Changes

10. ST Morphology

11. STEMI Territories
Localizations

12. STEMI

13. STEMI

14. STEMI

15. Responsible Vessel(s)
STEMI
Location
Leads
Responsible Vessel(s)
Reciprocal Change
Anterior
V1 – V4
Septal: V1 – V2
LAD
II, III, aVF
Lateral
I, aVL, V5, V6
RCA
Circumflex
III, aVF, V1
Inferior
RCA (80%)
Circumflex (15%)
Both (5%)
aVL, I
Posterior
V1 – V3
(Depression)

16. Context 2000 ACEP Qualifier
“ST-segment elevations greater than 0.1 mV in 2 or more contiguous leads that are not characteristic of early repolarization or pericarditis, nor of a repolarization abnormality from LVH or BBB in patients with clinical presentation suggestive of AMI.”2
2 Critical issues in the evaluation and management of adult patients presenting with suspected acute myocardial infarction or unstable angina. Ann Emerg Med 2000;35:

17. Early Repolarization

18. Early Repolarization Normal variant Males > Females ECG Findings:
Diffuse, Concave up ST Elevation 2-5mm (Usually precordial)
Notched J-Point
Prominent T-Waves
Temporal stability

19. Early Repolarization “Benign” Early Repolarization
Increased prevalence of early repolarization in idiopathic VF
Most pronounced with inferior J-Point elevation
Increased risk of cardiac death (ie – sudden arrythmia)
J-Point 1mm: RR 1.28, 95% CI 1.05 – 1.59
J-Point 2mm: RR 2.98, 95% CI 1.85 – 4.923
Isolated BER in limbs leads should prompt ACS investigations
3 Tikkanen JT, Anttonen O, Junttila MJ, et al. Long-term outcome associated with early repolarization on electrocardiography. N Engl J Med Dec 24;361(26):

20. Pericarditis

21. Pericarditis Diffuse ST Elevation Diffuse PR Depression Caveat: aVR
ST Depression, PR Elevation

22. Pericarditis Stages – All 4 Present in ~50% of patients
I – ST Elevation, concordant T-Waves, PR Depression
II – ST segments return to baseline, T-Waves flatten
III – T-Wave inversion
IV – T-Wave resolution

23. Pericarditis Differentiation from STEMI Concave Up ST segments
ST elevation beyond contiguous leads
No simultaneous T-Wave inversion
Reciprocal changes absent
Serial ECGs not consistent with STEMI patterns
No Q-Wave development

24. Pericarditis vs. BER Differentiation of Pericarditis from BER
V6 ST/T Ratio
Pericarditis > 0.25
BER < 0.25

25. LVH

26. LVH Tall R waves lateral leads Deep S waves anterior precordial leads
Concave Up ST elevation, typically V1-V3
LAD

27. LBBB

28. LBBB
Wide QRS
Large, positive R wave without q or s waves in I, aVL, V6
Notched ‘M Shaped’ R wave V5, V6
Normal or leftward axis
ST depression and T wave inversion in leftward leads
ST elevation and upright T waves in right precordial leads

29. LBBB 7% of MI4 Significantly less likely to receive ASA
Increased in-hospital mortality
4 Go AS, Barron HV, Rundle AC, et al. Bundle-branch block and in-hospital mortality in acute myocardial infarction. National Registry of Myocardial Infarction. Ann Intern Med 1998 Nov 1;129(9):690-7.

30. LBBB Sgarbossa Criteria5 Score ≥ 3 98% specific 20% sensitive6
Criterion
Score
Concordant ST Elevation ≥ 1mm, any lead 5
ST Depression ≥ 1mm, V1-V3 3
Discordant ST Elevation ≥ 5mm, any lead 2
5 Sgarbossa EB, Pinski SL, Barbagelata A, et al. Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block. GUSTO-1 (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries) Investigators. N Engl J Med 1996 Feb 22;334(8):481-7.
6 Tabas JA, Rodriguez RM, Seligman HK, et al. Electrocardiographic criteria for detecting acute myocardial infarction in patients with left bundle branch block: a meta-analysis. Ann Emerg Med Oct;52(4): e1.

31. LBBB

32. LBBB ECG Evolution Anterolateral MI Anteroseptal MI
New S Waves in Leftward Leads
I, aVL, V6
Anteroseptal MI
Lateral q waves
I, aVL, V5-V6

33. RBBB? Can present with ST elevation No impact on initial QRS vector
Q waves are not changed

34. Conclusion Evaluate ECG in relation to clinical presentation
ST morphology
Dynamic ECG changes, serial ECGs
Look for reciprocal changes

35. Practice

36. Practice Inferior MI V1 Elevation: RV Infarct
ST Elevation III > ST Elevation II: RCA Occlusion

37. Practice

38. Practice Hyperacute Anterior MI Note Mobitz II Conduction Block
Malfunctioning His-Pukinje system
Suggests anterior occlusion
Ie - LAD occlusion
Mobitz I Conduction Block
Malfunctioning AV node
Suggests ‘dominant’ coronary occlusion
RCA or Circumflex

39. Practice

40. Practice
Posterior MI
Note ‘q’ waves in anterior leads

41. Practice

42. Practice
WPW

43. Practice

44. Practice
LBBB Concerning for MI

45. Practice

46. Practice
Anterior MI