STEMI-46

Published: March 3rd, 2016

Category: STEMI

Pre-hospital ECG:

IMG_4228

Emergency Department ECG:

ECG1Right-Side ECG

ECG2

Cardiac Cath Report

1. LMCA: Normal, patent.

2. LAD: Patent, transapical.

3. LCX: Patent, nondominant.

4. RCA: Prox 100% thrombotic occlusion, ongoing vessel after revascularization was patent with patent right PDA and ostial right margina 50%

PLAN: Successful single vessel PCI with stenting of the proximal-to-mid RCA

 

Teaching

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

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.gifECG-Anatomy-LITFL