Transcript Case Review: Prehospital STEMI Recognition

Amy Gutman MD
EMS Medication Director
[email protected]
 STEMI & PCI Overviews
 3 Case Reviews
 All cases occurred between
2007 & 2010 (blinded)
 STEMI responsible for 500,000 hospital admissions &
75,000 deaths annually
 Thrombosis (clots form coronary artery plaques) is
most common cause of STEMI
 Early reperfusion reduces mortality and morbidity by
“rescuing” heart muscle from ischemia and necrosis
 Door-to-balloon time for primary PCI of <90 mins
 Annual operative volumes of >400 procedures
 Recommendation that elective PCI not be
performed at facilities without onsite cardiac
surgery facilities to perform “rescue” CABG
Acute Coronary Syndrome (ACS)
STEMI
NSTEMI
Cardiac Markers
(Troponin, CKMB)
Unstable Angina
+
Myocardial Infarction
STEMI
PCI vs Fibrinolysis
Non-STEMI
Stress Test, Delayed Cath Lab
 STEMIs due to blockage of a coronary artery
 If treated within 90 mins, >25% of STEMIs regain complete
function of the heart muscle
 NSTEMIs due to sudden narrowing of a coronary artery
with preserved but diminished cardiac blood flow
 Pts with NSTEMI presumed to have unstable angina, & do not
necessarily require acute opening of a vessel
 Anticoagulation & antiplatelet agents prevent narrowed artery
from occluding, followed by stress testing & possibly delayed (1-3
days) coronary angiography
 If NSTEMI with continued CP, will proceed to catherization lab
 Fibrinolysis (“Clot Busters”)





50-60% achieve normal arterial flow
30% recurrence of ischemia
3-5% re-infarction
1-4% hemorrhagic CVA
20-30% contraindications for thrombolytics
 Active internal bleeding, recent stroke, uncontrolled HTN
 PCI
 95% normal arterial flow (TIMI 3)
 10-15% recurrence of ischemia
 1-3% re-infarction
 <1% hemorrhagic CVA
 Few contraindications
1. Patient Brought To Cath Lab
2. Cath wire threaded through femoral
or brachial artery
3. Wire passes through aorta & guided
into coronary arteries
RCA Blockage Before Stenting
RCA Opened After Stenting
Wall Affected
Septal
Anterior
Anteroseptal
Anterolateral
Inferior
Lateral
ST Segment Elevation
V1, V2
V3, V4
V1, V2, V3, V4
V3, V4, V5, V6, I, aVL
II, III, aVF
I, aVL, V5, V6
Artery
LAD
LAD
LAD
LAD, Circumflex
RCA, Circumflex
Circumflex
Wall Affected
Septal
Anterior
Anteroseptal
Anterolateral
Inferior
Lateral
ST Segment Elevation
V1, V2
V3, V4
V1, V2, V3, V4
V3, V4, V5, V6, I, aVL
II, III, aVF
I, aVL, V5, V6
Artery
LAD
LAD
LAD
LAD, Circumflex
RCA, Circumflex
Circumflex
EMTs & Paramedics Recognized for
Outstanding Patient Care
 42 yo WM with CC of “Chest Pain”
 PMH: CAD
 Allergies: Percocet
 TX: IV, O2, Monitor; ASA, NTG
Outstanding documentation & performance of
ACLS protocols!
 Admitted 7/14 with V2–V6 STEMI & VFib arrest
 <30 mins to cath lab from prehospital call
 Anterior – lateral STEMI progressed to inferior –
anterior – lateral ischemia just prior to cardiac cath
 100% LAD occlusion opened up with stent
 Discharged on 7/17 with normal heart function
 55 yo Black Male
 CC: Chest pain, generalized weakness, fatigue
 PMH: None
 Medications: None
 Allergies: None
 RX: IV, O2, Monitor, ASA
 Right ventricular
infarction complicates 40%
of I-STEMIs
 Isolated RV infarction
extremely uncommon
 Preload sensitive due to
poor RV contractility
 Develop rapid & severe
hypotension from nitrates
or preload-sensitive agents
 Hypotension in right
STEMI treated with fluids
 Nitrates contraindicated
 ST elevation V1 (only standard lead looking directly at RV)
 ST elevation in lead III > II

Lead III more “right facing” than lead II & more sensitive to injury current
 Magnitude of ST elevation in V1 > ST elevation in V2
 ST segment in V1 isoelectric & ST segment in V2 depressed
 Combination of ST elevation in V1 & ST depression in V2 highly
specific for RV MI
 Right ventricular infarction confirmed by ST elevation in right-
sided leads (V3R-V6R)
 Place leads V1-6 in a mirror-
image position on the right
side of the chest
 Leave V1 & V2 in usual
positions & transfer leads V36 to right side of chest (i.e.
V3R to V6R).
 Most useful lead is V4R,
obtained by placing V4 lead in
5th RICS MCL
 ST elevation in V4R has
sensitivity of 88%, specificity
of 78% in diagnosis of RV MI
•Good Documentation of HPI & treatment
•Excellent justification of why NTG appropriately not given
•Followed ALS Protocols
 3 Vessel Disease:
 Circumflex
 Left Anterior Descending
 Right Coronary Artery
 Important Point:
 This young patient with no prior disease was a
walking “time bomb” who likely would have died or
had severely decreased quality of life if he had not
gotten to a cath lab immediately
 Admitted on 12/14
 Prehospital notification of anterior STEMI
 Door to Balloon 22 mins (4 mins in ED for CXR EKG
to r/o aortic dissection)
 RCA and proximal LAD stents
 Discharged 12/17 with normal heart function
 43 yo W Male
 CC: Chest pain that “started 20 minutes ago”
 PMH: HTN, NIDDM
• Great documentation of HPI, Exam, EKG findings, &
Treatment & Change in Symptoms post Treatment
• Hypotension post NTG makes you
think of what type of infarction?
• What is the immediate treatment?
 Stent of 100% occluded
RCA
 Discharged from
hospital 3 days post
catherization
 Diagnosed with
inferior MI
 Post cath echo showed
minimal heart
damage
 Recognition, pre-notification, & early cardiac
catherization are keys to improving survival in
STEMI patients
 These patients walked out of the hospital who
would have otherwise died due to outstanding
care provided by the EMTs & paramedics