chapter Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ 6 Wide Complex Tachycardia

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Chapter 6 Objectives Describe the possible pitfalls in diagnosing wide complex tachycardia Describe the potential complications resulting from misdiagnosing WCT Describe four simple criteria for differentiating VT from SVT Identify VT vs. SVT on a series of 12-Leads

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Pifalls in WCT Reliance on Lead II Reliance on the machine Vital signs/patient presentation Atrial fibrillation SVT is more common? 61

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Machine Logic

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Clinical Logic/Primary Survey Is the QRS >120 ms? Look at axis criteria (can be helpful) Look at the morphology in Leads V1 and V6 Look for concordance (all up or all down) Is AV dissociation present? Patient history/meds 62

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ First Criteria for VT Extreme right axis Upright complex in V1 (MCL-1) 99% diagnostic for VT 63

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Example of VT 63

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Another Axis Criteria Right axis deviation Negative V1 (MCL-1) 90% specific for VT 64

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Example: RAD + Negative V1 64

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Morphology Clues to VT Lead V1 (MCL-1) with positive deflection Taller left peak than right (a) Steeple sign (single upright peak) (b) Fireman’s hat (sloped) (c) Each diagnostic of VT 64

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Morphology Clues to VT Lead V1 (MCL-1) negative deflection Fat R wave (more that 40 ms wide) (a) Notch or slur to the initial downstroke (b or c)

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Morphology Clues to VT Lead V6 (MCL-6) Predominately negative deflection in V6 indicates VT 65

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Lead V6 Criteria 65

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Concordance All V-leads up or down All up: suggestive of VT but R/O WPW All down: suggestive of VT, R/O LBBB 66

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Negative Concordance 66

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Positive Concordance WPW Best seen in Leads V3-V6, I, and aVL Delta waves diagnostic (slurred upstroke R wave) Short PR interval 66

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ RS Interval Measure from the start of the R wave to the nadir point (tip) of the S wave RS >100 indicates VT 67

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ A-Fib? Irregular rhythm Wide complexes can form during tachycardia Rate-dependent BBB 68

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Capture or Fusion Beats Arrow on the 6th complex indicates an escape beat or fusion beat If seen it is diagnostic of VT (AV dissociation)

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Patient History Two questions: Have you had a heart attack before? Did you have fast heart rates after your MI? If yes to both, odds of VT are 86% with a wide complex tachycardia 67

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Recap of Criteria Start at the top of the criteria List all that are positive for VT 69

Page, 12-Lead ECG for Acute and Critical Care Providers © 2006 by Pearson Education, Inc. Upper Saddle River, NJ Practice Cases Ventricular Tachycardia

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