2 Context CP and ST Elevation common ED presentation Correct ECG interpretation impacts management decisions and patient outcomeCertain patients with CP and ST elevation require rapid intervention via thombolysis or PCIMisdiagnosis potentially harmful
3 Context 1996 ACC/AHA Class I Recommendation for Thrombolysis “ST elevation greater than 0.1 mV in two or more contiguous leads.”11 Ryan TJ, Anderson JL, Antman EM, et al. ACC/AHA guidelines for the management of patients with acute myocardial infarction. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Acute Myocardial Infarction). .J Am Coll Cardiol Nov 1;28(5):
5 Context 2000 ACEP Qualifier “ST-segment elevations greater than 0.1 mV in 2 or more contiguous leads that are not characteristic of early repolarization or pericarditis, nor of a repolarization abnormality from LVH or BBB in patients with clinical presentation suggestive of AMI.”22 Critical issues in the evaluation and management of adult patients presenting with suspected acute myocardial infarction or unstable angina. Ann Emerg Med 2000;35:
16 Context 2000 ACEP Qualifier “ST-segment elevations greater than 0.1 mV in 2 or more contiguous leads that are not characteristic of early repolarization or pericarditis, nor of a repolarization abnormality from LVH or BBB in patients with clinical presentation suggestive of AMI.”22 Critical issues in the evaluation and management of adult patients presenting with suspected acute myocardial infarction or unstable angina. Ann Emerg Med 2000;35:
18 Early Repolarization Normal variant Males > Females ECG Findings: Diffuse, Concave up ST Elevation 2-5mm (Usually precordial)Notched J-PointProminent T-WavesTemporal stability
19 Early Repolarization “Benign” Early Repolarization Increased prevalence of early repolarization in idiopathic VFMost pronounced with inferior J-Point elevationIncreased risk of cardiac death (ie – sudden arrythmia)J-Point 1mm: RR 1.28, 95% CI 1.05 – 1.59J-Point 2mm: RR 2.98, 95% CI 1.85 – 4.923Isolated BER in limbs leads should prompt ACS investigations3 Tikkanen JT, Anttonen O, Junttila MJ, et al. Long-term outcome associated with early repolarization on electrocardiography. N Engl J Med Dec 24;361(26):
21 Pericarditis Diffuse ST Elevation Diffuse PR Depression Caveat: aVR ST Depression, PR Elevation
22 Pericarditis Stages – All 4 Present in ~50% of patients I – ST Elevation, concordant T-Waves, PR DepressionII – ST segments return to baseline, T-Waves flattenIII – T-Wave inversionIV – T-Wave resolution
23 Pericarditis Differentiation from STEMI Concave Up ST segments ST elevation beyond contiguous leadsNo simultaneous T-Wave inversionReciprocal changes absentSerial ECGs not consistent with STEMI patternsNo Q-Wave development
24 Pericarditis vs. BER Differentiation of Pericarditis from BER V6 ST/T RatioPericarditis > 0.25BER < 0.25
28 LBBBWide QRSLarge, positive R wave without q or s waves in I, aVL, V6Notched ‘M Shaped’ R wave V5, V6Normal or leftward axisST depression and T wave inversion in leftward leadsST elevation and upright T waves in right precordial leads
29 LBBB 7% of MI4 Significantly less likely to receive ASA Increased in-hospital mortality4 Go AS, Barron HV, Rundle AC, et al. Bundle-branch block and in-hospital mortality in acute myocardial infarction. National Registry of Myocardial Infarction. Ann Intern Med 1998 Nov 1;129(9):690-7.
30 LBBB Sgarbossa Criteria5 Score ≥ 3 98% specific 20% sensitive6 CriterionScoreConcordant ST Elevation ≥ 1mm, any lead5ST Depression ≥ 1mm, V1-V33Discordant ST Elevation ≥ 5mm, any lead25 Sgarbossa EB, Pinski SL, Barbagelata A, et al. Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block. GUSTO-1 (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries) Investigators. N Engl J Med 1996 Feb 22;334(8):481-7.6 Tabas JA, Rodriguez RM, Seligman HK, et al. Electrocardiographic criteria for detecting acute myocardial infarction in patients with left bundle branch block: a meta-analysis. Ann Emerg Med Oct;52(4): e1.
38 Practice Hyperacute Anterior MI Note Mobitz II Conduction Block Malfunctioning His-Pukinje systemSuggests anterior occlusionIe - LAD occlusionMobitz I Conduction BlockMalfunctioning AV nodeSuggests ‘dominant’ coronary occlusionRCA or Circumflex