5th May 2025

Background

Atrial arrhythmias are arrythmias that are generated above or at the level of the atrioventricular node (AVN) and follow the normal His-Purkinje bundle system to rapidly activate the ventricles. These encompass a wide variety of abnormal heart rhythms caused by a multitude of underlying aetiologies. When assessing and managing atrial arrhythmias, follow the standard resus council guidelines for managing arrhythmias:

• Is there evidence of haemodynamic instability? If so, needs synchronised DC shock
• Is the rhythm fast or slow?
• Are the QRS complexes broad or narrow (i.e. <120ms)? Atrial arrhythmias are generally narrow complex (although beware of atrial tachycardias with variable block/aberrant conduction which may appear broad complex!)
• Is the rhythm regular or irregular?

Image Source: Wikimedia Commons (2017). Cardiac Conduction System, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Cardiac_conduction_system.jpg (Accessed 1 May 2025).