Tips & Tricks To Demystify 12 Lead ECG Interpretation

Tips and Tricks toDemystify 12 LeadECG InterpretationMission: Lifeline North DakotaRegional EMS and Hospital ConferenceSamantha Kapphahn, DOEssentia Health- Interventional CardiologyJune 5th, 2014

Disclosures None

Agenda Role of EMS in pre-hospital STEMIIdentification “Where is my MI?!?!?!?!” ST-Elevations and the DifferentialDiagnosis

EMS Role in Activation Education and Recognition– Your eyes won’t “see” if you don’t know what youare looking for. Action– Knowledge leads to empowerment The above leads to improved outcomes– Significantly improved DTB Mortality, Morbidity Standard of Care How we are “judged”

ECG 101 Representationof bio-electricalcurrents– using leadspositioned atset referencepoints on thebody

ECG 101 Continued

“What is the ST segment?” Represents the phase in cardiac cyclebetween ventricular depolarization andrepolarization Iso-electric relative to TP segment Measured starting at J-point

TPSegment

What exactly is a STEMI? ST-Elevation Myocardial Infarction– WHO criteria Ischemic chest pain for 20 minutes ECG changes Rise and fall of serum biomarkers (CK-MB,troponin)

“Typical” Chest Pain Substernal chest discomfort–Radiation to shoulder, neck, jaw, back,arms May be epigastric, “burning,”associated with vomiting Onset with exertion or emotionalstress–Often lasting 20 minutes or more Relief with rest or nitroglycerin

Defining ST Elevation ST segments measured– At J point if relative to PR segment– At 0.06-0.08s from J point if relative to TPsegmentChan, Brady, Harrigan, et al. ECG in Emergency Medicine and Acute Care. 1 stEd.

Defining ST Elevation Minnesota Code– 1 mm ST elevation in one or more of leads I,II, III, aVL, aVF, V5, V6, or 2 mm STelevation in one or more of leads V1-V4 AHA/ACC– ST elevation at the J point in at least 2contiguous leads of 2 mm in men or 1.5mm in women in leads V2–V3 and/or of 1mm in other contiguous chest leads or thelimb leads

Localizing an MI

Location of Myocardial Infarction Anteroseptal Anterior Anterolateral Extensive AnteriorV1-V3rS V1, V2-V4V4-V6, I, aVLV1-V6 /- I, aVL

Localization of MyocardialInfarction Lateral (high) Inferior Inferolateral PosteriorI, aVLII, III, aVFII, III, aVF, V5, V6R/S V1 1

Suspected Posterior MI Suspected MI with a non-diagnostic ECGRecord leads V7-V9Correlates with posterior wall MILeft circumflex infarct related artery in allV7: posterior axillary lineV8: posterior scapula lineV9: Left border of spineV5-V9: same horizontal plane as V4J Am Coll Cardiol 1999;34:748.

RV Infarct IWMI ST elevation in V1 RV infarct Or use of Right-sided chest leads

RV Infarction Higher in-hospital mortality: 31% vs 6%Higher in-hospital complication: 64% vs 28%No difference in post-hospital courseIn-hospital complications: VT, heart block,myocardial rupture, cardiogenic shock orreinfarctionN Engl J Med 1993;328:981-8.

“But there is a left bundlebranch block ” Try to obtain and compare to priorECGs/establish if different from baseline Keep in mind presentation ofpatient!!

Sgarbossa Criteria Sum score of 3: 90% specificity for MISgarbossa N Engl J Med 1996;334:481-7.

Sgarbossa N Engl J Med 1996;334:481-7.

“But don’t all ST elevations meanan MI?” No! Beware of mimics Always keep in mind clinical presentation

“But how often does this reallyhappen ?” Of 123 adult chest pain patients with STsegment elevation 1mm, 63 patients(51%) did not have myocardial infarctions. These non-MI were mainly– LBBB (21%) and– LVH (33%). Otto LA, Aufderheide TP. Evaluation of ST segment elevation criteria for the prehospitalelectrocardiographic diagnosis fo acute myocardial infarction. Ann Emerg Med 1994; 23 (1):17-24.

ACS Clinical Presentation– Chest Pain*– Diaphoresis– Dyspnea– Fatigue– Nausea– Syncope– Sudden Cardiac Death

Some reasons why there areSTEMI masqueraders .

Differential Diagnosis of ST Elevation MIPrinzmetal’s anginaTakotsubo syndromeVentricular aneurysm ordyskinesis or akinesis Acute pericarditis Early repolarization LVH or LBBB Myocarditis Hypercalcemia Tumor invading LVTrauma to the ventriclesHypothermiaPost DC cardioversionIntracranial hemorrhageHyperkalemiaBrugada syndromeType 1C antiarrhythmicdrugsBraunwald 8th edition, 2008

“Atypical” Chest Pain Sharp in nature (Pleurisy, pericarditis)Positional (Pericarditis, musculoskeletal)Tearing quality (Aortic disection)Pain worsened with respiration (Pleurisy,pericarditis)

Morphology of STE Concave shape STE – non AMI causes AMI causes – usually demonstrateApex ofconvex/straight STET waveJ pointConvex STEConcave STE

Benign Early RepolarizationConcave STELarge amplitude TwaveNotching or slurring ofJ point

PericarditisGoldberger AL. Goldberger: Clinical Electrocardiography: A Simplified Approach. 7thed: Mosby Elsevier; 2006.

PericarditisPRDepression

HyperkalemiaHyperacute Twaves

ST Elevation morphologies in BrugadaSyndromeRBBB with RSRpattern rather thanrSR pattern andthere is associatedSTE

Key Points What you know and do matters!!!! Learn from Experience (yours, others,feedback) Clinical presentation is as important (if notmore) than what is on the ECG.

Apex of T wave Convex STE Concave STE . Notching or slurring of J point Concave STE Benign Early Repolarization Large amplitude T . Pericarditis PR Depression . Hyperkalemia Hyperacute T waves . ST Elevation morphologies in Brugada Syndrome RBBB with RSR pattern rather than rSR pattern and there is associated STE . Key Points What you know .