Patent ID: 8374691

Claim:
For use by an implantable system, a method for discriminating between ventricular tachycardia (VT) and supraventricular tachycardia (SVT), comprising: (a) detecting atrial intervals indicative of atrial rate and ventricular intervals indicative of ventricular rate within a window leading up to and following the onset of a tachycardia; (b) determining whether a valid atrial interval decrease is detected within the window by (b.1) determining whether an atrial interval decrease that is greater than an atrial interval decrease threshold is detected for a pair of consecutive atrial intervals within the window, and (b.2) if the atrial interval decrease is detected, determining whether the detected atrial interval decrease is valid based on atrial intervals before and after the detected atrial interval decrease; (c) determining whether a valid ventricular interval decrease is detected within the window by (c.1) determining whether a ventricular interval decrease that is greater than a ventricular interval decrease threshold is detected for a pair of consecutive ventricular intervals within the window, and (c.2) if the ventricular interval decrease is detected, determining whether the detected ventricular interval decrease is valid based on ventricular intervals before and after the detected ventricular interval decrease; and (d) discriminating between VT and SVT based on results of step (b) and (c); wherein step (d) comprises determining that the detected atrial intervals and the detected ventricular intervals within the window are indicative of SVT if both a valid atrial interval decrease is detected and a valid ventricular interval decrease is detected within the window, and the valid atrial interval change occurs prior to the valid ventricular interval change.