Patent ID: 7251526

Claim:
An active implantable medical device of the defibrillator, cardiovertor and/or implantable antitachycardia pacemaker type, including: means for sensing ventricular and atrial cardiac activity; means for delivering an antitachycardia therapy able to apply selectively a defibrillation shock, a cardioversion shock and an antitachycardia pacing stimulation; means for detecting patient activity; means for delivering antibradycardia stimulation able to deliver ventricular and atrial stimulation pulses at a stimulation frequency determined according to detected patient activity, said stimulation frequency having a maximum stimulation frequency, the stimulation pulses being delivered at a rate defined according to a calculated escape interval including an atrio-ventricular delay and a ventriculo-atrial delay; first means for analyzing the detected cardiac activity with respect to a given threshold frequency of analysis and determining a frequency of cardiac activity and when the determined frequency of ventricular cardiac activity is greater than said given threshold frequency of analysis, said first analyzing means being able to recognize and discriminate the presence of a ventricular tachycardia and a ventricular fibrillation, said means for delivering antitachycardia therapy being responsive to a detected ventricular tachycardia or a detected ventricular fibrillation by delivering an appropriate antitachycardia therapy; wherein said antibradycarda therapy means further comprises said maximum stimulation frequency being higher than said threshold frequency of analysis; and second means for analyzing the cardiac activity and detecting in said cardiac activity a particular succession of events corresponding to a presence or an appearance of a spontaneous ventricular tachycardia, said second analyzing means further comprising means for prolonging the duration of the ventriculo-atrial delay until the later of the end of said calculated escape interval and the end of a programmed maximum interval of detection of ventricular tachycardia corresponding to the aforementioned threshold frequency of analysis increased by a tolerance delay.