ECG interpretation: NSTEMI
Primary PCI and direct admission of high risk NSTEMI
Joanne Simpson Golden Jubilee National HospitalWednesday 17th February 2016
Aims
· Recognise the ECG patterns which occur in NSTEMI· Focus on those which occur most commonly· Difficult ECG scenarios
NSTEMI definitionST elevation myocardial infarction (STEMI)
· acute chest pain and persistent ST elevation
· generally reflects an acute total coronary occlusion
· immediate reperfusion by primary angioplasty
Non ST elevation myocardial infarction (NSTEMI)
· acute chest pain with or without ECG changes
· partial occlusion of a coronary artery
Myocardial Infarction
NSTE-ACS
Secondary Prevention/Long-Term ManagementManagement Prior to
NSTE-ACS
Onset of NSTE-ACS-Initial recognition and management in the ED by first responders or ED personnel -Risk stratification-Immediate management
Hospital Management-Medication-Conservative versus invasive strategy-Special groups-Preparation for discharge
Final Dx
Cardiac Biomarker
ECG
Working Dx
Presentation Ischemic Discomfort
ACS
No ST Elevation
NQMI
STEMINSTEMIUA
Unstable AnginaQwMI
ST Elevation
Noncardiac Etiologies
* *
NSTEMI definition
Assessment of a patient with suspected ACS
NSTEMI: considerations
Clinical spectrum
Symptom free
Ongoing ischaemia
Haemodynamic instability
Cardiac arrest
• Ongoing pain• Marked ST depression• Heart failure• Electrical or haemodynamic
instability
NSTEMI: ECG changes
· persistent or transient ST-segment depression
· T-wave inversion
· flat T waves or pseudo-normalization of T waves
· normal ECG
1. What does this ECG show?
1. What does this ECG show?
1. T wave flattening inferiorly
2. Normal ECG
3. T wave inversion
4. ST depression
ST depression
2. What does this ECG show?
2. What does this ECG show?
1. Normal ECG
2. T wave inversion
3. ST elevation
4. ST depression
3. What does this ECG show?
3. What does this ECG show?
1. Normal ECG
2. T wave inversion
3. ST elevation
4. ST depression
Pre-hospital ECG
Wellen’s syndrome
· T waves: deeply inverted or biphasic
· Critical stenosis of left anterior descending artery
· Patients are high risk
Difficult ECGs
· Mimics are common
· Aim remains not to miss STEMI or high risk NSTEMI
· Low threshold for discussion
1. What does this ECG show?
1. What does this ECG show?
· ST elevation anteriorly
· ST depression
· Left bundle branch block
· Long QT interval
2. What does this ECG show?
2. What does this ECG show?
· Left ventricular hypertrophy
· Anterior ST elevation
· ST depression
· Normal ECG
3. What does this ECG show?
· ST depression
· Anterior ST elevation
· Left ventricular hypertrophy
· Broad QRS complex
3. What does this ECG show?
Electrolyte abnormality
· Potassium, sodium, calcium and magnesium all essential for normal electrical activity of heart
· Characteristic ECG changes but many are non specific
· Consider in:
- underlying kidney disease
- vomiting, diarrhoea and dehydration
Summary
· The clinical presentation is paramount
· ECG changes in combination with positive troponin highly suggestive of NSTEMI
· Be aware of mimics
Extra ECGs if have time
ST depression
ST depression
T wave inversion
Wellen’s syndrome
Wellen’s syndrome
Right bundle branch block