Dual Chamber Arrhythmia Detection in the Implantable Cardioverter Defibrillator

Abstract

Dual Chamber Arrhythmia Detection hy ICD. Introduction. Dual chamber implantable cardioverter detibrillator (ICD) technology extended ICD therapy to more than termination of hemodynamicaly unstable ventricular tachyarrhythmias. It created the basis for dual chamber arrhythmoa management. In which dependable detection is important for treatment and prevention of both ventricular and atrial arrhythmias. Methods and Results. Dual chamber detection algorithms were investigated in two Medironic dual chamber ICDs; the 7250 Jewel AF (33 patients) and the 7217 Gem DR (31 patients). Both ICDS use the same PR Logic algorithm to interpret tachycardia as ventricular tachycardia (VT), supraventricular tachycardia (SVT), or dual (VT+SVT), The accuracy of dual chamber detection was studied in 310 of 1,367 spontaneously occurring tachcardias in which rate criterion only was not sufficient for arrhythmia diagnosis. In 78 epidoses there was a double tachycardia, in 223 episodes. SVT was detected in the VT or veutricular fibrillation zone, and in 9 episodes arrhythmia was detected outside the boundaries of the PR Logic functioning. In 100% of double techycardias the VT was correctly diagonsed and reveived priority treatment. SVT was seen in 59 (19%) episodes diagonsed as VT. The causes of inappropriate detection were (1) algorithm failure (inability to fulfill the PRJ Cardiovasc Electrophysiol. Vot. 11. pp. 1105‐1115. October 2000)