Ischemia EKG Lecture Flashcards
What can indicate ischemia in the absence of MI
T wave inversion (coronary blood flow decreased without producing an infarction
What lead show pathological T wave inversion
V2 through V6
Describe the T wave inversion criteria for myocardial ischemia
- at least 1 small square deep
- present in 2+ contiguous leads that have dominant R waves
- aren’t present on an old EKG or are changing over time
List the lateral leads
I, aVL, V5, V6
List the inferior leads
II, III, aVF
List the septal leads
V1, V2
List the anterior leads
V3, V4
Describe Wellen’s syndrome
- significant T wave inversion in V2, V3 (may be biphasic)
- indicative of critical stenosis of L anterior descending coronary artery
Describe the EKG for hypokalemia
- widespread down sloping ST depression
- T wave flattening/inversion
- prominent U waves
Describe a pathological Q wave
current or prior MI
- greater than 1mm wide
- greater than 2mm deep
- 25% of QRS complex depth
- seen in leads V1-3
(inferior Q waves in leads II, III, aVF; anterior Q waves seen in V1-4)
Describe the types of ST segment changes that represent myocardial ischemia
greater than 0.5mm at the J point in 2+ contiguous leads
(2+ mm in 3+ leads = NSTEMI)
Describe the ST segment presentation in L main coronary artery occlusion
widespread ST depression with ST elevation in aVR > 1mm
localized ST depression is more likely to represent reciprocal changes due to …..
STEMI - corresponding ST elevation may be subtle
What non-ischemic condition can show widespread horizontal ST depression on EKG
SVT
Describe the clinical criteria for a STEMI
clinical symptoms consistent with ACS (20+ mins) with persistent EKG features in 2+ contiguous leads
new LBBB = STEMI
