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.
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.