The simplest initial approach is to think of all wide complex tachycardias as Vtach. As you gain more experience and knowledge you can learn the nuances of wide complex tachycardias. Specifically, irregular wide complex tachycardias that may represent SVT with aberrancy or preexcitation vs polymorphic Vtach in Torsades De Pointes. For now, you should think about any wide complex tachycardia as Vtach until proven otherwise.
The first branch point in wide complex tachycardia (WCT) with a pulse is to determine if the patient is stable vs unstable:
Definition of an unstable (U/S) patient includes 4 findings. All are signs of end-organ dysfunction that we can assess clinically:
- Altered mental status (end organ dysfunction of the CNS).
- SBP < 100 (end organ dysfunction of the circulatory system).
- Chest pain concerning for ACS.
- Acute pulmonary edema or signs of acute heart failure.
- Stable patients get Medicine (M), while unstable patients get Edison or Electricity (E) in the form of a synchronized shock.
Once you have determined that your patient is stable you can trial medications, understanding that if they do not work you need to prepare for cardioversion:
- 20 mg/min until you suppress the arrhythmia, then maintenance infusion of 1-4 mg/min x 6 hours.
- Stop if QRS duration increases > 50% or if there is hypotension
- 150mg over 10 min, followed by 1 mg/min drip over 6 hours, then 0.5mg/min over the next 18 hours
- Preferred in setting of acute MI or LV dysfunction
Go through your C-A-Bs and alert your staff that this is a code situation (get more hands on deck!).
Connect the crash cart pads to the patient and be ready for a synchronized cardioversion!
Make sure that the ‘sync’ function is ON to avoid shocking while the heart is repolarizing (avoiding the R-on-T phenomenon).
Give patient synchronized shock starting at 100J and working your way up to 200J.
If the patient is unstable but still conscious you may need to give patient pain (fentanyl IV) and even sedation (half dose etomidate) medications.
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