Basic ecg interpretation and management of different anatomical myocardial infarctions

1. AN APPROACH TO
ACUTE CHEST PAIN
THE FIRST 20 MINUTES

2. COMPLAINS
OF ACUTE
CHEST PAIN,
WHAT DO
YOU DO?
YOUR PT IS TRIAGED
AS A RED CODE

3. THATS A
LONG ALGORITHM!!!

4. OUR JOB IS TO STABILISE
THEN TO STRATIFY INTO A RISK CATEGORY

5. ALTHOUGH NOT FOOLPROOF IT IS INVALUABLE
OUR MAIN WEAPON IS THE ECG
• ONCE WE HAVE AN ECG IT LEADS US DOWN THREE DISTINCT
PATHS
• WE WILL ATTEMPT TO LOOK AT SIMPLE ECG TRACINGS AND
IDENTIFY WORRYING TRAITS
• INTERPRETING ECGS IS AN ESSENTIAL SKILL FOR ALL
DOCTORS
• BOOKS SUCH AS ‘ECG MADE EASY’ OR ‘THE ONLY ECG BOOK
YOU WILL EVER NEED’ ARE EASILY AVAILABLE ONLINE

6. ST ELEVATION
MYOCARDIAL INFARCT

7. CAN YOU NAME THE ABNORMALITIES IN THE ECG?
WHICH PARTS OF THE HEART HAVE SUFFERED AN INFARCT?
SHOULD I BE WORRIED?

8. CAN YOU NAME THE ABNORMALITIES IN THE ECG?
WHICH PARTS OF THE HEART HAVE SUFFERED AN INFARCT?
SHOULD I BE WORRIED?

9. WHAT NEXT?
SO NOW WE’VE MADE THE DIAGNOSIS
• THIS IS A HIGH RISK ACS
• THE PT REQUIRES EITHER PCI OR THROMBOLYSIS
• HOW MUCH OF MORPHINE CAN WE GIVE?
• BETWEEN 2-10MG DEPENDING ON
RESPONSE
• WHY IS THE MORPHINE SO IMPORTANT?
• PAIN AND CATECHOLAMINE DECREASE

10. THIS IS THE POINT YOU INVOLVE THE PHYSICIANS
THE PATIENT IDEALLY NEEDS URGENT REPERFUSION
• WE DO NOT NEED TO WAIT
FOR CARDIAC MARKERS
• WHAT DO I ASK THE
PATIENT ABOUT?
• HOW DO I PRESENT THE PT
TO THE PHYSICIAN?

11. JUST SOME GENERAL GUIDES
INTERPRETING AN ECG
• FIRST DETERMINE THE AXIS
• THEN THE RATE
• THEN THE RHTHYM
• THEN LOOK FOR CHANGES AND ABNORMALITIES

12. LETS TRY AND NAME
SOME INFARCTS

14. ANTEROSEPTAL

16. MORE OF A SEPTAL MI.
NOTE THE T-WAVE INVERSIONS.
DO WE NEED THE PATIENTS AGE AND GENDER?

17. • WHEN WE LOOK AT V2 AND V3 THESE ARE SPECIAL
CONSIDERATIONS
• IN WOMEN > 1.5 BLOCKS IS WORRYING
• IN MEN ITS WORRYING IF
• > 40 YEARS, 2 BLOCKS
• < 40 YEARS , 2.5 BLOCKS

19. INFERIOR MI
IS THERE RIGHT VENTRICULAR SPREAD?
AS A RULE OF THUMB, IF THE ST ELEVATION IN III >II, THEN YES
BUT YOU HAVE TO DO A 16 LEAD ECG TO CONFIRM!

20. HOW TO PLACE THE
ELECTRODES
WE CAN SEE THE
ST ELEVATION MUCH
BETTER NOW

22. POSTERIOR MI, ALONG WITH INFERIOR
AND RV
WE CONFIRM WITH AN 18 LEAD ECG
IT VERY RARELY OCCURS IN ISOLATION

23. WE CAN SEE THE ST ELEVATIONS
NOW V7-V9

24. AND NOW NSTEMI AND
UNSTABLE ANGINA

25. IS OUR PT
HIGH RISK
OR LOW
RISK?
WE CONCENTRATE
MAINLY ON 9 & 10

26. WE NEED TO CONSIDER EACH PT
IT DEPENDS
• IS THE PT UNSTABLE? - HIGH RISK
• ARE THERE DYNAMIC CHANGES IN THE ECG? - HIGH RISK
• ARE THE CARDIAC MARKERS RISING OR ELEVATED INITIALLY? -HIGH RISK
• IS THE PT DETERIORATING IN OUR CARE?
• TACHYCARDIAS
• HEART FAILURE
• PERSISTENT PAIN
• HAEMODYNAMIC INSTABILITY
• ALL POINT TOWARDS HIGH RISK

27. THEY ARE MANAGED AS STEMI PTS
IF OUR PT IS HIGH RISK?
• AND LOW RISK PATIENTS
REQUIRE FURTHER
EVALUATION BY A
CARDIOLOGIST
• THEY MUST NEVER BE SENT
HOME
• THEY REQUIRE SERIAL ECGS
AND CARDIAC MARKERS
• ALWAYS GIVE THEM LOW
DOSE MORPHINE ONLY, 2-5MG
AND NOT MORE, AND ONLY IF
TNT IS NOT CONTROLLING SXS

28. BUT IT SOUNDS LIKE CARDIAC PAIN
AND THE LOW RISK PT
• FIRST, HAVE I CONSIDERED ALTERNATE DIAGNOSIS?
• PERICARDITIS
• DISECTING ANEURYSM
• OESOPHAGEAL RUPTURE
• PULMONARY EMBOLI OR PNEUMOTHORAX
• SECOND, IF YOU ARE STRONGLY SUSPICIOUS OF A CARDIAC CAUSE,
THEN ADMIT FOR SERIAL ECGS AND CARDIAC MARKERS
• MANY MI’S SHOW NO ECG CHANGES
• CARDIAC MARKERS TAKE TIME TO RISE

29. JUST A FEW LAST THINGS
TO NOTICE ON THE ECG

33. ST ELEVATION IN AVR IS ALSO VERY, VERY WORRYING

34. BI PHASIC T-WAVES IN V2-V3
SHOULD MAKE YOU SUSPECT
A SERIOUS MI EVEN IF THE
PATIENT IS PAIN FREE

35. CAN YOU MAKE THE DIAGNOSIS?
WINNER IS EMPLOYEE OF THE MONTH!!
BE SYSTEMATIC,
NAME ALL THE CHANGES

36. THIS IS A PULMONARY EMBOLUS
LOOK OUT FOR
1)TACHYCARDIA 2) RBBB
3) S1Q3T3 PATTERN
4)T-WAVE INVERSIONS V2-V3
5) R-AXIS DEVIATION (NOT SEEN HERE)

37. OUR FIRST 20 MINUTES ARE CRITICAL
IN CONCLUSION
• AT THE VERY LEAST YOU
CAN GET AN ECG AND
STRATIFY YOUR PATIENT
• YOU CAN START THE
PROCESS OF SAVING YOUR
PATIENT
• IT IS IMPOSSIBLE TO TEACH
YOU THE SUBTLETIES OF
ECGS IN THESE FEW
SLIDES, BUT AT LEAST YOU
CAN RECOGNISE OBVIOUS
PATTERNS