Worldwide Clinical Experience with a New Dual-Chamber Implantable Cardioverter Defibrillator System

• Published in: Journal of cardiovascular electrophysiology 2001-05, Vol.12 (5), p.521-528
• Main Authors: SCHOELS, WOLFGANG, SWERDLOW, CHARLES D., JUNG, WERNER, STEIN, KENNETH M., SEIDL, KARLHEINZ, HAFFAJEE, CHARLES J.
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Algorithms; Arrhythmias, Cardiac - diagnosis; Arrhythmias, Cardiac - therapy; atrial fibrillation; Atrial Fibrillation - diagnosis; Atrial Fibrillation - mortality; Atrial Fibrillation - therapy; Canada - epidemiology; Cardiac Surgical Procedures - instrumentation; Defibrillators, Implantable; Equipment Safety; Europe - epidemiology; Female; Follow-Up Studies; Humans; implantable cardioverter defibrillator; Male; Middle Aged; North America - epidemiology; Predictive Value of Tests; Survival Analysis; Tachycardia, Ectopic Atrial - diagnosis; Tachycardia, Ectopic Atrial - mortality; Tachycardia, Ectopic Atrial - therapy; Tachycardia, Ventricular - diagnosis; Tachycardia, Ventricular - mortality; Tachycardia, Ventricular - therapy; Time Factors; Treatment Outcome; ventricular tachyarrhythmias
• ISSN: 1045-3873; 1540-8167
• DOI: 10.1046/j.1540-8167.2001.00521.x

New Dual‐Chamber ICD. Introduction: Management of atrial tachyarrhythmias represents a significant challenge in patients with implantable cardioverter defibrillators (ICDs). Drug therapy of these arrhythmias is limited by moderate efficacy, ventricular proarrhythmia, and drug‐device interactions. This study tested the safety and efficacy of a new dual‐chamber ICD to detect and treat atrial as well as ventricular tachyarrhythmias. Methods and Results: A dual‐chamber ICD (Medtronic 7250 Jewel AF) was implanted in 293 of 303 patients at 49 centers in Europe, Canada, and North America. Specific data were collected at implant and during a mean follow‐up period of 7.9 ± 4.7 months. There were no clinically evident failures to detect and treat ventricular arrhythmias. In patients with at least one of the dual‐chamber detection criteria activated, 1,056 of 1,192 episodes of ventricular tachycardia or fibrillation detected were judged to be appropriate (89% positive predictive accuracy). Therapy efficacy was 100% in the ventricular fibrillation zone and 98% in the ventricular tachycardia zone. Positive predictive accuracy for detection of atrial episodes was 95% (1,052/1,107). For episodes classified as atrial tachycardia by the device, the efficacy of atrial antitachycardia pacing and high‐frequency (50‐Hz) burst pacing was 55% and 17%, respectively. High‐frequency burst pacing terminated 16.8% of episodes classified as atrial fibrillation, and atrial defibrillation had an estimated efficacy of 76%. The actuarial estimates of 6‐month complication‐free survival and total survival were 88% and 94%, respectively. Conclusion: This novel dual‐chamber ICD is capable of safely and effectively discriminating atrial from ventricular tachyarrhythmias and of treating atrial tachyarrhythmias without compromising detection and treatment of ventricular tachyarrhythmias.