Being a resuscitation educator commonly requires discussion of the dilemmas of arrhythmia management. This is an area we don’t delve into everyday so achieving true ‘expertise’ is a challenge.
Guidelines often come to the rescue in such life-threatening and time dependent situations. The American Heart Association (AHA) has released updated recommendations for the management of ventricular arrhythmias:
- ACS generally causes VF or polymorphic VT.
- A scar from an old MI generally causes monomorphic VT.
- VT/VF storm generally occurs within 3 months of an MI. It is defined as >/= 3 episodes of sustained VT, VF, or appropriate ICD shocks in a 24-hour period.
Summary from Journal Feed
- If in doubt with wide complex tachycardia, assume it’s VT (class I).
- For hemodynamically stable VT, procainamide is the preferred pharmacologic agent (class IIa). However, cardioversion remains a class I recommendation.
- In hemodynamically unstable ventricular arrhythmias, electricity is undoubtedly first priority. If that fails, amiodarone is the preferred pharmacologic agent (class IIa).
- IV beta blockers may be useful (class IIa) for patients with:
- VT/VF storm despite DCCV and antiarrhythmics
- Polymorphic VT due to MI
- Adrenaline 1mg every 3-5 minutes “may be reasonable” in cardiac arrest (class IIb).
- Consider emergent PCI in all patients after out-of-hospital cardiac arrest, particularly with initial shockable rhythm. Absence of STEMI does not rule out culprit coronary lesion and may be seen in 30% of patients.
- Contrary to common teaching, accelerated idioventricular rhythm (AIVR) is not a marker of reperfusion. Instead it is more strongly associated with infarct size.
- Some drugs can worsen or unmask Brugada syndrome. (drugs of concern include procainamide (not available in Australia), flecainide, TCAs, lithium, propofol, cocaine, cannabis and alcohol).
- Digoxin isn’t the only cause of bidirectional VT. Catecholaminergic polymorphic VT (exercise or stress induced VT) can also cause it.
- Long QT syndrome: males in childhood and postpartum females are at greatest risk for ventricular arrhythmia.