Patent ID: 8788026

Claim:
A method performed in an implantable system for determining a type of an arrhythmia in a patient's heart, the method including the steps of: a. monitoring initial atrial and ventricular rates of the heart; b. detecting a pathological initial ventricular and/or atrial rate; c. upon detecting a pathological initial ventricular and/or atrial rate during a first time period: (1) administering a nontherapeutic amount of an antiarrhythmic cardioactive drug over a second time period, the nontherapeutic amount being less than a therapeutic amount typically prescribed for the pathological initial ventricular and/or atrial rate; (2) detecting the response of the ventricular and atrial rates to the nontherapeutic amount of the drug; (3) determining differences between: (a) the ventricular and atrial rates in response to the drug, and (b) the initial atrial and ventricular rates; (4) determining a type of atrial or ventricular arrhythmia from the differences.