METHOD AND APPARATUS FOR SEPARATION OF VENTRICULAR TACHYCARDIA FROM VENTRICULAR FIBRILLATION FOR IMPLANTABLE CARDIOVERTER DEFIBRILLATORS

摘要

A method and apparatus for differntiating between ventricular tachycardia and ventricular fibrillation includes a pair of electrodes (20, 22) located on a single catheter (12) which, in conjunction with an implantable cardioverter device (14), utilize two channel ventricular algorithms for ventricular tachycardia and ventricular fibrillation separation. Two closely spaced unipolar electrograms demonstrate similar morphology and consistency during rhythms with broad coherent activation (such as sinus rhythm and ventricular tachycardia). Conversely, for incoherent rhythms (ventricular fibrillation and polymorphic ventricular tachycardia), activation between the electrodes proved to be dissimilar and inconsistent. The cross correlation of the two depolarizations measures similarity between electrogram morphology, and interquartile range measures consistency in a passage. The method and apparatus of the present invention is able to address the limitation of existing algorithms and provide accurate separation of ventricular fibrillation from other rhythms.