STEMI-46

Pre-hospital ECG:

Emergency Department ECG:

Right-Side ECG

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