ST DEPRESSION Flashcards
DDX
STEMI OR NEAR STEMI:
Reciprocal Changes
Posterior MI
deWinter’s
STE aVR
NON-STEMI / ISCHEMIA:
Non-STEMI
LVH
OTHER:
Digoxin
RECIPROCAL CHANGES
Reciprocal changes may preceed STEMI
I and aVL are reciprocal to II, III and aVF
POSTERIOR MI
STD in V1, V2 -> get a 15 lead ECG (V7, V8, V9)
Horizontal ST dep v1-v3 (the right precordial leads)
If ST depression >=0.5 m in v1-v3 do posterior leads
Prominent R waves (R/S ratio > 1) and upright T waves in V1-V3
POSTERIOR LEADS (15 LEAD):
ST elevation >= 0.5 mm in V7-V9
Flipped T in aVL (reciprocal of inf/RCA MI)
DEWINTER’S
T Waves are large, peaked, together with STD
Criteria:
Tall symmetric peaked T waves in V1-6
WITH
Upsloaping ST depression > 1 mm at the J point in V1-V6
Absence of ST elevation in the precordial leads
Reciprocal ST segment elevation (0.5mm-1mm) in aVR
Proximal LAD Occlusion
~2% of acute LAD occlusions
STE IN aVR
ST elevation in aVR with co-existent multi-lead ST depression
Clinical Significance:
* Left main coronary artery (LMCA) stenosis
* Proximal left anterior descending artery (LAD) stenosis
* Severe triple vessel disease
* Hypoxia or hypotension
Proximal LAD critical occlusions
NON-STEMI
STD are planar or concave downward
Widespread STD may be due to global ischemia / metabolic
LVH
Sokolov-Lyon criteria:
S wave depth in V1 + tallest R wave height in V5-V6 > 35 mm
Non-Voltage Criteria:
STE Concave limited to V1 – V3
STE is modest in relation to large voltages
STD and strain (T Wave Inversion) lateral leads (V5, V6, I, aVL)
Changes to LBBB over time
STD are downslope due to subendocardial ischemia
Precordial Leads:
R wave in V4, V5 or V6 > 26 mm
Limb Leads:
R wave in lead I + S wave in lead III > 25 mm
R wave in aVL > 11 mm
R wave in aVF > 20 mm
S wave in aVR > 14 mm
DIGOXIN
Swooping STD
DDx: STD RIGHT PRECORDIAL LEADS
acute anteroseptal myocardial ischemia
reciprocal change associated with acute inferior MI
PMI.
