Thursday, February 18, 2016

Subtle ECG Findings in ACS

emDocs - February 15, 2016 - Authors: Santistevan J - Edited by: Koyfman A & Bright J
  • ST-segment elevation in lead aVR portends a worse prognosis in ACS and often predicts the need for CABG.
  • ST-segment elevation in aVR can be caused by any of the following 4 mechanisms:
  • LMCA insufficiency
  • Very proximal LAD occlusion or complete LMCA occlusion
  • Multi-vessel coronary artery disease
  • Diffuse subendocardial ischemia
  • Patients with complete occlusion of the LMCA often present in cardiogenic shock and require immediate revascularization.
  • Patients with NSTEMI and ST elevation ≥ 1mm in aVR are likely to have multi-vessel or LMCA disease and are likely to require CABG, therefore withholding Clopidogrel may be prudent."
emDocs - February 17, 2016 - Authors: Santistevan J - Edited by: Koyfman A & Bright J
"In this post, we are going to review 4 causes of abnormal T-waves:
  • Hyperacute T-waves in AMI
  • The de Winter T-wave pattern
  • Pseudonormalization of T-waves
  • Hyperkalemia
  • Hyperacute T-waves are often the first manifestation of complete vessel occlusion; they are wide, bulky and prominent.
  • Hyperacute T-waves are not necessarily tall, and small T-waves can still be hyperacute when paired with a low-amplitude QRS complex.
  • De Winter T-waves represent LAD occlusion (a STEMI equivalent) requiring immediate revascularization.
  • Previously inverted T-waves can appear normal and upright in the setting of acute vessel occlusion. This is known as pseudonormalization.
  • The tall T-waves associated with hyperkalemia are sharp, pointy, symmetric, and have a narrow base.
  • When in doubt, get serial ECGs (every 15 minutes) and use adjunctive information."