Patent ID: 8050758

Claim:
A method for controlling anti-tachyarrhythmia pacing (ATP), the method comprising: sensing a cardiac signal; detecting heart beats from the cardiac signal; detecting cardiac cycle lengths each being a time interval between two consecutively detected heart beats; detecting a tachyarrhythmia episode using the detected cardiac cycle lengths; classifying the detected tachyarrhythmia episode; initiating a primary duration when the tachyarrhythmia episode is detected; analyzing stability of cardiac cycle lengths during the primary duration; controlling an initiation of a secondary duration using the stability of cardiac cycle lengths analyzed during the primary duration and the classification of the detected tachyarrhythmia episode; analyzing stability of cardiac cycle lengths during the second duration if the secondary duration is initiated, wherein analyzing the stability of cardiac cycle lengths for the primary duration and analyzing the stability of cardiac cycle lengths for the secondary duration each include: detecting stable ventricular tachyarrhythmia clusters (SVTCs) from the cardiac signal, the SVTCs each including at least a specified minimum number of consecutively detected heart beats over which the cardiac cycle lengths meet a specified stability criterion; and declaring an SVTC detection in response to achieving the specified minimum number of consecutive heart beats over which the cardiac cycle lengths meet a specified stability criterion; and controlling a delivery of pacing pulses according to an ATP mode in response to a detected SVTC during the primary duration, a detected SVTC during the secondary duration if the secondary duration is initiated, and the classification of the detected tachyarrhythmia episode.