醫學筆記匯整 ED Notes

- 1mm (一小格) = 0.04 sec
- 5mm (一大格) = 0.2 sec

 快慢, 寬窄, 規則, 有無, 關係, STT change 

* 快慢 Rate : Tachy or brady

* QRS 寬窄 : 
   - Narrow : sinus, atrial, junctional 
   - Wide : ventricular, supraventricular with aberrant

* 規則 : Regular or irregular?
  regularly irregular or irregularly irregular?

* P 有無 : 
   - Absent : sinus arrest, atrial fibrillation
   - Present : morphology and PR interval may suggest
     sinus, atrial, junctional or even retrograde from ventricles

* P 和 QRS 關係 : 
   - AV association
   - AV dissociation

* STT change 

Broad Complex Tachycardias

 Regular 

    - Ventricular tachycardia ( VT )
    - Antidromic atrioventricular re-entry tachycardia (AVRT)
    - Any regular SVT with aberrant conduction
      e.g. due to bundle branch block, rate-related aberrancy

All regular BCTs should be considered to be VT until proven otherwise.

 Irregular 

    - Ventricular fibrillation ( VF )
    - Polymorphic VT
    - Torsades de Pointes
    - AF with WPW 
    - Any irregular SVT with aberrant conduction
      e.g. due to bundle branch block, rate-related aberrancy

Bradycardias

 P waves present 

Each P wave is followed by a QRS complex (sinus node dysfunction)

    - Sinus bradycardia
    - Sinus node exit block
    - Sinus pause / arrest

Not every P wave is followed by a QRS complex (AV node dysfunction)

    - AV block

 P waves absent 

Narrow complexes : Junctional escape rhythm

Broad complexes : Ventricular escape rhythm

Axis Interpretation : Lead I + Lead II + aVF 

Lead I + Lead II  both positive : -30° and +90° (normal axis)

只看 Lead I + aVF 會把 0 ~ -30° 的 normal axis 判讀成 LAD 

 Right Axis Deviation 

    - RVH
    - Acute right ventricular strain, e.g. pulmonary embolism
    - Lateral STEMI
    - Chronic lung disease, e.g. COPD
    - Hyperkalaemia
    - Sodium-channel blockade, e.g. TCA poisoning
    - Wolff-Parkinson-White syndrome
    - Dextrocardia
    - Ventricular ectopy
    - Secundum ASD – rSR' pattern
    - Normal paediatric ECG
    - Left posterior fascicular block – diagnosis of exclusion
    - Vertically orientated heart – tall, thin patient
 

 Left Axis Deviation 

    - LVH
    - LBBB
    - Inferior MI
    - Ventricular pacing /ectopy
    - Wolff-Parkinson-White Syndrome
    - Primum ASD – rSR’ pattern
    - Left anterior fascicular block – diagnosis of exclusion
    - Horizontally orientated heart – short, squat patient
 

 Extreme Axis Deviation 

    - Ventricular rhythms – e.g.VT, AIVR, ventricular ectopy
    - Hyperkalaemia
    - Severe RVH