Antiarrhythmic agents, also known as cardiac dysrhythmia medications, are a group of pharmaceuticals that are used to suppress abnormal rhythms of the heart (cardiac arrhythmias), such as atrial fibrillation, atrial flutter, ventricular tachycardia, and ventricular fibrillation. Many attempts have been made to classify antiarrhythmic agents. The problem arises from the fact that many of the antiarrhythmic agents have multiple modes of action, making any classification imprecise.
A modernized Oxford classification by Lei, Huang A recent publication has now emerged with a fully modernised drug classification. This preserves the simplicity of the original Vaughan Williams framework while capturing subsequent discoveries of sarcolemmal, sarcoplasmic reticular and cytosolic biomolecules. The result is an expanded but pragmatic classification that encompasses approved and potential anti-arrhythmic drugs. This will aid our understanding and clinical management of cardiac arrhythmias and facilitate future therapeutic developments. It starts by considering the range of pharmacological targets, and tracks these to their particular cellular electrophysiological effects. It retains but expands the original Vaughan Williams classes I to IV, respectively covering actions on Na+ current components, autonomic signalling, K+ channel subspecies, and molecular targets related to Ca2+ homeostasis. It now introduces new classes incorporating additional targets, including: Class 0: ion channels involved in automaticity Class V: mechanically sensitive ion channels Class VI: connexins controlling electrotonic cell coupling Class VII: molecules underlying longer term signalling processes affecting structural remodeling. It also allows for multiple drug targets/actions and adverse pro-arrhythmic effects. The new scheme will additionally aid development of novel drugs under development and is illustrated below