醫學筆記匯整 ED Notes

- Most important shockable cardiac arrest rhythm
- Ventricles suddenly attempt to contract at rates of up to 500 bpm

 Right Ventricular Outflow Tract (RVOT) Tachycardia 

- A form of monomorphic VT, generally considered benign

• VT
• SVT with aberrant conduction due to BBB
• SVT with aberrant conduction due to WPW
   
• Pace-maker tachycardia
• Metabolic : hyperkalaemia
• Poisoning with sodium-channel blocker (TCA)
  

Irregular wide QRS tachycardia 三個鑑別診斷

1.  Af + WPW 
   

AVRT (Atrio-ventricular reciprocal) : 1/3
有 accessory apathway, WPW

- Orthodromic : 90%, 走 AV node 當然 narrow QRS
                           會 short RP

 - Antidromic : 10%, 走 accessory apathway 所以 wide QRS !!
                          屬於 regular wide QRS tachycardia
                          會 long RP

 Polymorphic ventricular tachycardia ( PVT ) 
- A form of VT

• 12 lead EKG + Vital sign + Conscious 
     (即使 SVT 也可能 低血壓, 低血氧)

* 遇到 tachycardia 一定要先分析的四大重點 : 

1. Rate
2. Regular or Irregular
3. QRS wide or narrow
4. P or not