Marcin Dada, MD December 03, 2013

Transcription

1 STEMI Imposters Marcin Dada, MD December 03, 2013

2 Marcin Dada, MD Associate Director, Chest Pain Center Hartford Hospital, Hartford, CT Member, AHA Mission Lifeline Steering Committee

3 Outline of Topics STEMI Introduction (challenges) STEMI/ECG STEMI Imposters LBBB with. STEMI vs Pericarditis vs BER Early reciprocal changes in avl

4 Hospitalizations in the U.S. Due to Acute Coronary Syndromes (ACS) Acute Coronary Syndromes* 1.57 Million Hospital Admissions - ACS UA/NSTEMI 1.24 million Admissions per year STEMI.33 million Admissions per year Heart Disease and Stroke Statistics 2007 Update. Circulation 2007; 115: *Primary and secondary diagnoses. About 0.57 million NSTEMI and 0.67 million UA. 4

5 Mortality Reduction (%) 1. Time is Myocardium 2. Infarct Size is Outcome D C 20 0 Extent of Myocardial Salvage B A Time From Symptom Onset to Reperfusion Therapy (h) Critical Time-dependent Period Goal: Myocardial Salvage Time-independent Period Goal: Open Infarct-Related Artery Gersh BJ, et al. JAMA. 2005;293:979.

6 Time To Treatment Goals for Primary PCI 2013 ACCF/AHA guidelines for the management of ST-elevation myocardial infarction: executive summary: a report of the ACC/AHA Task Force on Practice Guidelines. J Am Coll Cardiol 2013;61:

7 Door-to-balloon times down, but inhospital mortality unchanged. 7

8 Total System Delay (First Medical Contact to Device) and Long-Term Mortality Each hour of delay associated with 10% risk of death Terkelsen JAMA. 2010;304(7):

9 Challenges Mean symptom duration is still 2 hours before FMC, and 40% of patients do not contact EMS. An ACC AHA performance measure sets a DIDO goal of 30 minutes for internal quality-improvement purposes, but the metric is not used for public reporting, and the best regional STEMI systems are averaging 45 minutes.

10 Challenges Nearly 70-80% of STEMI patients in the US present to community hospitals without PCI capability For patients requiring interhospital transfer, first-door-to-balloon time is 90 minutes or less in only 33% of cases and 120 minutes or less in only 66%.

11 SUMMARY The primary opportunity for reducing total ischemic time and time to treatment, and for improving outcomes, now lies in the pre-hospital STEMI system of care. Currently: 90% of patients who present directly to PCI-capable hospitals treated within 90 min, median time of approximately 60 minutes

12 Evidence Based Approach

13 Summary By incorporating pre hosp 12L ECGs into routine evaluation of potential of cardiac ischemia, STEMI patients are identified at the point of their earliest interaction with the medical system. By acting on this diagnostic information and using it to trigger an organized, system wide response, STEMI pts achieve reperfusion of the IRA sooner, and thus can expect better outcomes.

14 ECG Expertise The eye does not see what the mind does not know.

15 Systematic approach Step 1: Determine rate and rhythm Step 2: Inspect the 12L for waveform changes (STEMI) Examine one representative complex Step 3: Determine if STEMI is suspected 1 mm in two contiguous leads (if so, find the region) Step 4: Identify additional considerations for STEMI STEP 5: Final interpretation Balance the evidence Decide how compelling is the case for STEMI

16

17 Reciprocal Changes ST depression in leads opposite infarction Strengthen suspicion of AMI Are not necessary to identify STEMI

18 Determination of ST Segment Morphology

19 Computer Anterior STEMI

20 STEMI Imposters LVH BBB (often LBBB) Ventricular Rhythms (often paced) Pericarditis Benign Early Repolarization

21 Ventricular Rhythm/LBBB Ventricles contract sequentially, widening the QRS So, if QRS is prolonged, an imposter is present it could be either. Normal QRS < 0.12sec

22 LVH Does not widen the QRS Instead of increasing the width increases the height Many formulas are available

23 LHV STEP 1: compare V1 and V2, deciding which one has the deepest negative deflection 25mm 27mm

24 LHV STEP 2: compare V5 and V6, deciding which one has the tallest positive deflection 21mm 19mm 27mm

25 LHV STEP 3: add the numbers, and if the sum is 35mm or more, suspect LVH V2 27 mm V5 21mm >35 mm Meets voltage criteria for LHV

26 Important The presence of an imitator does not rule out AMI If you suspect Infarct BEFORE the 12L you must still suspect Infarct AFTER the 12L

27 Question According to the 3 step approach, after comparing V1 and V2, and comparing V5 and V6, and adding the numbers, suspect LVH if the sum is: a) 25mm or less b) less than 35mm c) More than 35mm

28 Top STEMI Imposters LVH BBB (often LBBB) Ventricular Rhythms (often paced) Early Benign Repolarization Pericarditis

29 BER/Pericarditis Very unlikely to see reciprocal changes with either BER or Percarditis Percarditis: Diffuse ST elevation (concave)

30 STEMI/STEMI IMPOSTERS LVH BBB Ventricular paced rhythm Normal QRS QRS >0.12 Early Benign Repolarization Pericarditis Lack of reciprocal changes

31

32 STEMI OR 1) LVH 2) LBBB 3) Ventricular paced rhythm 4) BER 5) Pericarditis

33

34 STEMI OR 1) LVH 2) LBBB 3) Ventricular paced rhythm 4) BER 5) Pericarditis

35 62-year-old female with chest discomfort:

36 STEMI OR 1) LVH 2) LBBB 3) Ventricular paced rhythm 4) BER 5) Pericarditis

37 Systemic analysis STEMI Diagnosis 3 questions 1. ST segment elevation present? 2. QRS complex is normal? 3. ST segment depression is present? If YES to all 3 questions STOP ASKING SO MANY QESTIONS DO SOMETHING!

38 ECG STEMI Not a STEMI Definite Maybe ST elevation in 2 contiguous leads Non of the STEMI imposters Borderline ST elevation Clear ST elevation, but imposter is present No ST elevation in 2 contiguous leads

39 Normal LBBB Rule of appropriate discordance (true for pacemakers)

40 Left Bundle Brunch Block Diagnosis of AMI Sgarbossa criteria

41 LBBB with?

42 LBBB with AMI

43 LBBB with?

44 ECGs and Pericarditis 1. Factors that rule in STEMI 1. STD except in V1 and avr 2. STE in III>II 3. Horizontal and convex upward STE 4.! Waves that you KNOW are NEW 2. Factors that suggest AP 1. Friction rub 2. PR depression in multiple leads (only reliably seen in Viral AP, transient)

45 STEMI or AP

46 STEMI or AP

47 AP vs BER Positional changes in pain Fishhook ->BER Height STE:T wave in V6 Old ECGs

48 BER vs (MI and Pericarditis) BER MI/Pericarditis

49 STEMI vs AP/BER AMI PERICARDITIS, BER STE,STD DIFFUSE OR LOCALIZED STE, FREQUENT RECIPROCAL STD USUALLY DIFFUSE STE, NO RECIPROCAL STD (EXCEPT V1 OR AVR) ST SEGMENT MORPHOLOGY IF STE II AND III EVOLVING CHANGES STRAIGHT, HORIZONTAL, CONVEX OR CONCAVE STE III > II (USUALLY) USUALLY ST SEGMENTS AND T CONCAVE UPWARDS STE II > III (ALMOST ALWAYS) UNLIKELY IN ED

50 Posterior Wall AMI Leads V1-V3 Horizontal ST Depressions Additional features Large R wave Upright T wave Frequently co-existing inferior or lateral

51 Case 56 yo. man presents c/o throat burning, nausea History of HTN, tobacco use, treated with maalox with mild improvement, patient wants to be discharged. 30 minutes later symptoms worsen (now with diaphoresis), ECG is obtained

52 Early Reciprocal Changes in avl (1)

53 Early Reciprocal Changes in avl (2)

54 Early Reciprocal Changes in avl (3)

55 Early Reciprocal Changes in avl The normal ECG lead avl Isoelectric ST-segment Upright T-wave Acute Inferior wall MIs Common reciprocal changes ST-segment down sloping in avl T-wave inversions in avl Reciprocal changes in avl can precede the development of inferior lead abnormalities (Marriott)

56 Class I Recommendation If the ECG is non-diagnostic of STEMI, but the patient remains symptomatic and there is a high clinical suspicion for STEMI, serial ECGs at 5 to 10-minute intervals or continuous 12L ST-segment monitoring should be performed to detect the potential development of ST elevation 2004 ECG Guidelines

57 CONCLUSION Continued efforts are needed to educate patients about STEMI symptoms and about calling 911 to permit EMS triage, treatment, and transport, as STEMI teams shift their focus from in-hospital to prehospital treatment delays.

58 Discussion Please ask questions and share your thoughts Thank you