Clinical implications of new insights into mechanism of antiarrhythmic drug action.

A classification system of antiarrhythmic drugs should help the clinician to select the optimal antiarrhythmic drug for a particular arrhythmia in an individual patient. This goal cannot be achieved by the Vaughan Williams classification system. Other important goals of this classification system were to provide the clinician with some information about proarrhythmic effects and about the possibility of combining particular antiarrhythmic agents. To date, a subdivision of class III antiarrhythmic agents has not been accomplished.