STEMI-12

Published: July 16th, 2015

Category: STEMI

Pre-hospital ECG:

2015-07-16 10.55.11

ED ECG

ECG

Right side ECG: 2 mm elevation in V4R

 

Cath Report:

LCA:  large vessel which has normal origin and gives rise to the LAD and LCX. No angiographic stenosis.

LAD: normal size vessel with no angiographic stenosis and traverses to the apex giving off three small to medium sized diagonals that are widely patent.

LCX: normal size vessel with mild luminal irregularities and gives rise to four obtuse marginal branches that are also patent.

RCA: is a large dominant vessel that gives rise to the PDA and is 100% proximally occluded with thrombus and TIMI O flow.

Intervention: 1 stent placed to 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