EKG
Sgarbossa Criteria (STEMI in presence of LBBB)
1. ST elevation ≥ 1 mm concordant with QRS complex (most predictive of AMI of the 3 criteria)
2. ST depression ≥ 1 mm in lead V1, V2, or V3
3. ST elevation ≥ 5 mm where discordant with QRS complex
Modified 3rd rule: ST elevation ≥ 0.25 x S-wave (Ann Emerg Med. 2012 Dec;60(6):766-76)
SVT vs VT
Left Ventricular Hypertrophy
The Sokolow-Lyon index:
S in V1 + R in V5 or V6 (whichever is larger) ≥ 35 mm
R in aVL ≥ 11 mm
The Cornell voltage criteria:
S in V3 + R in aVL > 28 mm (men)
S in V3 + R in aVL > 20 mm (women)
Romhilt-Estes point score system ("diagnostic" >5 points; "probable" 4 points):
Other voltage-based criteria for LVH include:
Lead I: R wave > 14 mm
Lead aVR: S wave > 15 mm
Lead aVL: R wave > 12 mm
Lead aVF: R wave > 21 mm
Lead V5: R wave > 26 mm
Lead V6: R wave > 20 mm
Echo: normal LV myocardial thickness (end-diastole) 0.6-1.1cm
ECG animation: http://www.cardioohrid.org.mk/userfiles/Flash/0038a.swf
Practice EKG Interpretation: http://ecg.bidmc.harvard.edu/maven/mavenmain.asp
Lewis Lead for atrial activity: http://emcrit.org/wee/lewis-lead/