ECGs by diagnosis

Arrythmias

See Cards: Arrythmias (DDX)

MI

1. T wave usu tracks w/ the QRS, thus if QRS primarily negative, twi is not necessarily abnl (nl twi in V1).
2. ST elevation non-specific, also w/ LVH & strain, LBBB, CA spasm, pericarditis, "early repol", hyperK, dig/TCA's, CVA, Vent. aneurysm, hypothermia.
3. Non-transmural: ST dep at least 1.0mm, twi.
4. II, II, AVF for inf. MI
5. V1-3 for anteroseptal inf.
6. I, AVL, V4-6 for lat. wall inf.
7. V1 or V2-6 anterolat.
8. Large R and ST depression in V1-V2= POST. INFARCT! Post MI usu seen w/ inf MI b/c RCA supplies both in 90% of pts!
9. Pts w/ inf. infarction +/or post wall mi often also have RV mi, need R sided leads!!
10. STE >/= 1mm in V3R or V4R suggest RV MI!
11. STE > 2wks= poss vent aneurysm!
12. STE in avR and avL = LMA stenosis
13. STE in avR and V1 = LAD or LMA stenosis
14. if STE > 1.5 mm in avR pt has 75% mortality from AMI --> activate cath lab (unless pt is in SVT, then STE is allowed)

Infarct notes

1. inf wall: recip. In 1 and AVl. Downward sloping ST in AVl is often first sign.
2. Any ST depression in V1 to V3 in a LBBB is pathological and suggestive of a post. Wall MI.
3. Poor r waves progression-no r's by V4
4. persistent t-wave elevation 6 wks post mi-vent. Anyeursm.anteroseptal with biphasic/inverted t wave

Pericarditis

1. Stage I: ST elevated in precordial leads, esp. V5-6 & I-II. Isoelectric or depressed ST in V1. PR depression in II, AVF, V4-6.
2. Stage II: ST returning to baseline. T wave amplitude decreases.
3. Stage III: ST isoelectric. TWI where prior STE.
4. Stage IV: Resolution of T wave changes.
5. Also ST:T ratio >0.25 in V6

(Depressed PR, Diffuse ST elevation, Scooping upwardly concave ST segments, Notching at the end of the QRS)

Electrolyte Disorders

HyperK

1. 5.5-6.6 -> tall peaked T, deep S in I and V6, QRS nml
2. 7.0-8.0 -> QRS widens, slurred initial and term QRS, ST elevation, low wide P's, AV blocks, SA arrest, bradycardia.
3. >8.0 -> widened QRS, Vfib, asystole.

HypoK

1. 3.0-3.5 no change or flat T' sand U's in V2-3, QT interval and QRS nml.
2. 2.7-3.0 U taller, T smaller, esp. V2-3
3. <2.6 ECG change includes tall U's, QT and QRS wnl.

HyperCa

1. Increased QRS duration (slight)
2. ST short or absent
3. Short corrected QT.
4. PR long

HypoCa

1. slight decrease in QRS.
2. ST and corrected QT long
3. PR short.
4. T's flat to inverted.

CNS

1. SAH, IC bleed, stroke, can see diffuse wide deep, blunted inverted T's. and QT prolonged

Pacemakers

1. Should be in the apex of R vent.
2. ECG should mimic LBBB, w/ L axis.

PE

1. S1Q3T3
   1. (good specificity, poor sensitiviy)

Source

DONALDSON 17/09 (Adapted from Niemann/Lampe)