ECG predictors of culprit artery in acute myocardial infarction

1. ECG predictors of culprit artery in acute myocardial infarction Dr.DeepakRaju

2. North American Societies of Imaging divided left ventricle into 4 walls–septal,anterior, lateral and inferior and subdivided into 17 segments

7. LAD- AW(1,7,13) by diagonals ,ant.septum (2,8,14) by septalbranches,RBB by 1stseptal ,apex(17) &sometimes part of seg.15 as wraps around apex(80%) • RCA-RV,IW(4,10,15),inf.septum(3,9,15),part of lat.wall(5,11,16)if dominant • LCX-anterior lateral wall(6,12,16),inferior lateral wall(5,11) part of inf wall(4)and seg10&15 if dominant

8. LV divided into two zones –anteroseptal and inferolateral • 12 different locations of coronary occlusions 6 in the anteroseptal zone and 6 in the inferolateral zone can be recognised

9. Anteroseptal zone-LAD and branches • Proximal to S1 & D1 • Prox to D1,distal to S1 • Distal to S1&D1 • Prox to S1 ,distal to D1 • Selective D1–D2 occlusion • Selective S1–S2 occlusion

10. Proximal to S1 & D1 • Large area of infarct • 31% cases (Engelen et al;JACC 1999) • Injury vector points upward,anteriorly • Right or left depending on predominentseptal or diagonal invt.

11. Proximal to S1 & D1

13. ECG pattern • ST↑ in V1 to V4−5 and aVR • ST↓ in II, III, aVF and V5−6 • ST ↑ in aVL or aVR depending on predominentinvt. of lateral or septal • ST dep. III+aVF≥2.5 mm s/o LAD prox to D1(Fiol 2006) • ST elev.in aVR+V1>ST dep V6-s/o LAD prox to S1(Fiol,2006) • ST dep II>III

14. Prox to D1,distal to S1 • Injury vector upward ,anteriorly and to left • 11% cases • Large infarct-basal anterolateral may be spared

15. Prox to D1,distal to S1

16. ECG pattern • ST↑ inV2 toV5−6,I,aVL • ST ↓ in II,III,aVF • ST ↓ in III>II • Wrap around LAD-prox. to D1-Lead III ST dep.with a positive T &ST elevation in aVL(Porter et al 1998)

17. Distal to S1&D1 • Area at risk involves inferior third of LV-apical infarction & some invt of inf wall • Injury vector directed anteriorly,downward and to left • 48% of cases

18. Distal to S1&D1

19. ECG pattern • ST↑ in V2 toV4−5,not in V1 • Slight ST↑ in II,III,aVF,not in aVR(slight ST dep) • ST elev.II>III • ST elev. In V3-4> V1 • Short LAD less evident changes

20. Prox to S1 ,distal to D1 • 11% cases • Injury vector downward anterior and to right

21. Prox to S1 ,distal to D1

22. ECG pattern • ST↑ in V1 to V4, V5,aVR • ST↑ in II, III(III>II) • ST↓ in V6

23. Criteria

24. Sensitivity low&specificity higher-absence of a criteria may not help • ST ↑ in V1 <2.5 failed to differentiate b/w prox. and distal • ST ↑ in a VL did not have much significance,ST dep. helped to localise • Q in V4-6 specific for distal to S1-presence of septal vector facilitating Q formation

25. Selective D1–D2 occlusion • Mid and apical antr. &mid and apical lateral wall • Injury vector –upward ,left ,anterior

26. Selective D1–D2 occlusion

27. Ecg pattern • ST↑ in I, aVL and sometimes V2 to V5−6 • ST↓ in II, III, aVF(ST dep.III>II) • ST↓ in V2-3 s/o D1+LCX or RCA

28. Selective S1 occlusion-antr.,upward &right

29. Ecg pattern • ST↑ in V1−2, aVR • ST↓ in I, II, III, aVF, V6(ST dep.II > III)

30. Algorithm for localisation-ST↑ant. leads

31. ST ↑in ant. &inf. leads

32. Inferolateral zone-LCX&RCA • Proximal RCA occlusion • Distal RCA occlusion • Dominant RCA occlusion • Proximal LCX occlusion • OM occlusion • Dominant LCX occlusion

33. Proximal RCA occlusion • Infwall,inferior part of septum,RV • Downward and to right • Sagittal plane-anterior if predominent RV invt,otherwise posterior • Changes in right leads transient • Lead V1 equally useful(Fiol 2004)-v1 equiphasic or elevated s/o RV invt.

34. Proximal RCA occlusion

35. Ecg pattern • ST↑ in II, III,aVF(III > II) • ST↓ in I,aVL • ST↑ in V4R with positive T • ST isoelectric or elevated in V1

36. Distal RCA occlusion-downward,right and posterior

37. Ecg pattern • ST↑ in II,III,andaVF(III > II) • ST↓ in I and aVL • ST↓ in V1−3 • Magnitude of ST elevation in inf leads>change in precordial leads

38. Dominant RCA • Inferolateral wall also involved • Downward and to right • Anterior or posterior depends on RV invt • ST elevation in lateral leads-local injury vector

39. Dominant RCA

40. ECG pattern • ST↑ in II, III, aVF(III > II) • ST↓ in V1−3 < ST ↑ in II, III, aVF. • Prox.RCA occlusion-ST in V1−3 ↑/equiphasic • ST dep in V1 if distal RCA • ST ↑ in V5−6 ≥ 2mm(Nikus ,2004)

41. Proximal LCX • Lateral wall and inferior wall(inferobasalseg.) • Downward ,posteriorly and to left

42. Proximal LCX

43. Ecg pattern • ST↓ in V1−3 greater than ST↑ in inferior leads • ST↑ in II, III, aVF(II >III) • Usually ST↑ in V5−6 • ST↑ in I, aVL(I >aVL)

44. OM occlusion • Anterior and posterior part of lateral wall • Injury vector left and posteriorly • Upward or downward depending on area of invt. • Diagonal –upward and anteriorly

45. OM occlusion

46. Ecg pattern • Slight ST ↑ in I,aVL,V5−6 • Slight ST ↑ II, III,aVF may occur • Slight ST ↓ in V1−3

47. Dominant LCX occlusion • Inferior lateral and inferobasalseg • Injury vector in frontal plane b/w +60 &+90,posteriorly

48. Dominant LCX occlusion

49. ECG pattern • ST↑ in II,III,aVF(II≥III) greater than ST ↓ in V1−3 • ST ↓ aVL usually not in I • Prominent ST ↑ in V5−6