A 25-year-old man presents to the ED with a broad complex tachycardia that is irregularly irregular. The patient is haemodynamically uncompromised. An anaesthetist is not available to assist with immediate DC cardioversion.
What is the best initial treatment option?
This man may have an accessory pathway with rapidly conducted AF. Adenosine, digoxin, verapamil, and beta-blockers should all be avoided as they prolong the AV node refractory period and thus may increase conduction down an accessory pathway. This increases the risk of rapidly conducted AF becoming VF. Intravenous class I antiarrhythmic drugs (e.g. procainamide, flecainide, propafenone) can be used as well as amiodarone, but DC cardioversion is the treatment of choice if there is haemodynamic compromise or rapidly conducted AF down an accessory pathway.