STEMI-14

Published: August 2nd, 2015

Category: STEMI

Emergency Department ECG

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Right-side ECG

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Cath Report

LM– no angiographic stenosis noted

LAD– Proximal LAD has luminal irregularities, the mid LAD has a patent stent, the distal LAD has luminal irregularities. D1 is a small vessel, D2 is a larger vessel, no angiographic stenosis seen in both vessels

LCx– normal caliber vessel giving rise to a large OM1 branch, no angiographic stenosis seen

RCA– Dorminant vessel, proximal to Mid RCA has a hazy 90% stenosis in the stent body, just distal to the stent there is are 2 sequential stenosis, up to 60%, distal RCA has no angiographic stenosis. The ostium of the PDA has 40% stenosis. The PLV has luminal irregularities, the distal PLV has TIMI 1 flow

Intervention: Stents placed to proximal and mid RCA

 

Teaching

  • Right side MI
    • Complicates 40% of inferior MIs
    • Right ventricle is preload dependent which may lead to hypotension if Nitroglycerin is administered.  Treat with IV fluids and rapid transport.
  • Right side ECG
    • A complete set of right-sided leads is obtained by placing leads V1-6 in a mirror-image position on the right side of the chest (see diagram, below).
    • It may be simpler to leave V1 and V2 in their usual positions and just transfer leads V3-6 to the right side of the chest (i.e. V3R to V6R).
    • The most useful lead is V4R, which is obtained by placing the V4 electrode in the 5th right intercostal space in the midclavicular line. ST elevation in V4R has a sensitivity of 88%, specificity of 78% and diagnostic accuracy of 83% in the diagnosis of RV MI.
    • right-ventricular-leads.gifRVMI-2
  • Inferior MI
    • 40-50% of all myocardial infarctions.
    • more favorable prognosis than anterior myocardial infarction
    • Up to 40% of patients with an inferior STEMI will have a concomitant right ventricular infarction. These patients may develop severe hypotension in response to nitrates and generally have a worse prognosis.
      • Confirmed with Right sided ECG, Elevation in V4R
    • Up to 20% of patients with inferior STEMI will develop significant bradycardia due to second- or third-degree AV block. These patients have an increased in-hospital mortality (>20%).
    • ECG findings
      • ST elevation in leads II, III and aVF
      • Reciprocal ST depression in aVL (± lead I)
      • RCA (80%): Elevation in III > II, Reciprocal depression in I
      • LCx (20%): Elevation in III = II, No reciprocal depression in I