1. Clinical decision making in adult chest pain with ECG ST-segment elevation : STEMI vs Non-AMI cause of ST-segment abnormality

7. ED management of Chest pain
History
Physical Exam
Serum marker
ECG

8. Initial ECG High risk group
Significant abnormality or confound pattern
Pathologic Q waves
ST-segment or T wave change
LVH
LBBB
Ventricular paced rhythm
42% incidence of AMI
14% incidence of life threatening events
10% mortality rate

9. Initial ECG Low risk group Normal Minimal abnormality
Unchanged (when compared previous ECG)
14% incidence of AMI
0.6% incidence of life threatening events
0% mortality rate

10. ST segment elevation ACC/AHA guideline ST segment is measured at
At least 0.2mV of elevation in any 1 precordial lead
Greater than 0.1mV elevation in at least 2 anatomically contiguous precordial lead or in at least 2 adjacent limb leads
ST segment is measured at
A point 0.04 msec or 1mm after or the right of the J point at the end of QRS complex

12. ST segment elevation Magnitude of ST-segment change AMI 4.4mV
Summation mV
Non- AMI mV
Summation mV

13. ST segment elevation Anatomic distribution ACS : localized (3.4 leads)
Non-AMI : more wide spread (4.1 leads)
Regarding ST segment depression
Specific anatomical distribution is not helpful in diagnosis

14. ST segment elevation
ST segment Contour

15. ST segment elevation

16. ST segment elevation

17. ST segment elevation
QRS complex width and Amplitude

18. ST segment elevation
QRS complex width and Amplitude

19. ST segment elevation
QRS complex width and Amplitude

20. ST segment elevation
QRS complex width and Amplitude

21. ST segment elevation
QRS complex width and Amplitude

22. ST segment elevation
LVH :
V1 + R wave in V5 or V6
 more than 35mm

23. Medical decision making and diagnostic clinical pathway
Widened QRS complex
AMI itself does not increase the width of QRS
Abnormal intraventricular conduction
LBBB, VPR
Higher risk of AMI
Prompt Dx of AMI is extremely important

24. Medical decision making and diagnostic clinical pathway
Ventricular paced Rhythm

25. Medical decision making and diagnostic clinical pathway
LBBB
AMI in LBBB presentation

26. Medical decision making and diagnostic clinical pathway
Large amplitude QRS complex
Result in ST-segment/T-wave change
Opposite direction to QRS
Convex or concave
Serial ECG

27. Medical decision making and diagnostic clinical pathway
ST segment contour
Convex or oblique
Predictor of AMI : sensitivity 77%
specificity 97%
positive predictive value 94%
Don’t use for Rule out !!!
But effective in Rule in

28. Medical decision making and diagnostic clinical pathway
Reciprocal ST segment depression
ST-segment depression in leads that are opposite to those that exibiting STE
Criteria
ST-segment depression
Presence od ST-segment elevation in distal leads
Absence of confounding ECG pattern
LVH, LBBB, VPR
Sensitivity : 63% PPV : 30%
Absence of LVH, LBBB, VPR
Sensitivity & PPV : 93%

29. Medical decision making and diagnostic clinical pathway

30. Medical decision making and diagnostic clinical pathway
Serial ECG
“AMI is dynamic and evloving process with a predictable progression of changes”
3-4 hours after
0.5mm change in STE or STD
Q-wave development
T-wave inversion in 2 or more contiguous lead
 AMI sensitivity : 88%

31. Medical decision making and diagnostic clinical pathway
Serial ECG

32. Case conclusion

33. Case conclusion

34. Case conclusion

35. Case conclusion

36. Reference
Clinical decision making in adult chest pain with ECG ST segment elevation : STEMI vs Non-AMI cause of ST-segment abnormality