Post on 16-Feb-2017
ECG interpretation: STEMI
Primary PCI and direct admission of high risk NSTEMI
Joanne Simpson Golden Jubilee National HospitalWednesday 17th February 2016
Aims
· Revise the ECG patterns which occur in STEMI· Focus on those which are more difficult to
recognise, but not uncommon · Remember:
Some ECG patterns are not clear cut
Minimising missed STEMIs is the priority
1. What does this ECG show?
· Anterior ST depression
· Left ventricular hypertrophy
· Bundle branch block
· Inferior STEMI
2. What does this ECG show?
· Inferior T wave inversion
· Lateral T wave inversion
· Inferolateral T wave inversion
· High lateral STEMI
3. What does this ECG show?
· Left bundle branch block
· Anterior T wave inversion
· Posterior STEMI
· Atrial fibrillation
4. What does this ECG show?
· Left bundle branch block
· Left ventricular hypertrophy
· Anterior STEMI
· Atrial fibrillation
STEMI
· ST elevation myocardial infarction (STEMI)
Complete (or near complete) occlusion of a coronary artery
→ restriction of blood supply to heart muscle beyond
· This produces characteristic symptoms and ECG changes which allow:
rapid recognition of STEMI
prompt delivery of optimal reperfusion therapy
→ minimise infarct size, risk of future events, early and late mortality
STEMI
· ST elevation myocardial infarction (STEMI)
Complete (or near complete) occlusion of a coronary artery
→ restriction of blood supply to heart muscle beyond
· This produces characteristic symptoms and ECG changes which allow:
rapid recognition of STEMI
prompt delivery of optimal reperfusion therapy
→ minimise infarct size, risk of future events, early and late mortality
Different ECG patterns in STEMI
1. ST elevation reflecting occlusion of a coronary artery
2. Posterior infarct
3. Left bundle branch block
1. ST elevation reflecting occlusion of a coronary artery
- ‘injury current’ between normal and necrotic Tissue
- occurs in regional patterns
2. Posterior infarct
3. Left bundle branch block
Different ECG patterns in STEMI
ST elevation due to coronary occlusion
ECG leads over the territory of the occluded artery will show ST
elevation as the injury current travels toward them
ST elevation correlates to the territory of the occluded artery:
Inferior = RCA / LCx
Posterior = RCA / LCx
Lateral = LCx
Anteroseptal = LAD
Circumflex artery (LCx)
Left anterior descending artery (LAD)
Right coronary artery (RCA)
Correlating ECG leads with vessel territory
Inferior Lateral
AnteriorInferior leads
Anterior leads Lateral leads
ST elevation due to coronary occlusion
ST elevation in anterior leads
‘Reciprocal’ ST depression in inferior leads
ST elevation in inferior leads
Reciprocal ST depression in anterior leads
ST elevation due to coronary occlusion
ST elevation due to coronary occlusion
ST elevation in high lateral leads
‘Reciprocal’ ST depression in inferior leads
Different ECG patterns in STEMI
1. ST elevation reflecting occlusion of a coronary artery
- ‘injury current’ between normal and necrotic tissue
- occurs in regional patterns
2. Posterior infarct
- location means ST elevation is not seen
3. Left bundle branch block
Posterior wall infarction
Posterior infarct may be caused by RCA or LCx occlusion
- often associated with inferior or lateral ST elevation
Circumflex artery (LCx)
Left anterior descending artery (LAD)
Right coronary artery (RCA)
Posterior wall infarction
· No ECG leads ‘look’ directly at the posterior wall of the heart
· Anterior leads are directly opposite and will see the opposite of any current generated at the posterior wall
· posterior ST elevation= anterior ST depression
Different ECG patterns in STEMI
1. ST elevation reflecting occlusion of a coronary artery
- ‘injury current’ between normal and necrotic tissue
- occurs in regional patterns
2. Posterior infarct
- location means ST elevation is not seen
3. Left bundle branch block (LBBB)
- if NEW can indicate infarction
- if OLD can obscure ST elevation during an infarct
Left bundle branch block
QRS duration > 3 small squares
Negative QRS across anterior leads with poor R wave progression
Notched R wave in V6
V1
V6