EXPERIENCE WITH 3 DIFFERENT 3RD-GENERATION CARDIOVERTER-DEFIBRILLATORS IN PATIENTS WITH CORONARY-ARTERY DISEASE OR CARDIOMYOPATHY

Clinical investigations are being performed in multiprogrammable devic es whose therapeutic options include antitachycardia pacing, cardiover sion, defibrillation and bradycardia pacing. Three different third-gen eration devices were implanted in 46 research patients at 1 clinical c enter to document their safety and efficacy for the treatment of malig nant ventricular arrhythmias. Additionally, the purpose of the study w as to determine if antitachycardia pacing is a desirable and frequentl y used feature of tiered devices. The Medtronic PCD was implanted in 1 5 patients (12 men, mean age 60 +/- 13 years, mean ejection fraction 4 0 +/- 15%), the Ventritex Cadence in 21 patients (17 men, mean age 65 +/- 10 years, mean ejection fraction 38 +/- 12%), and the CPI VENTAK P Rx in 10 patients (8 men, mean age 63 +/- 14 years, mean ejection frac tion 31 +/- 8%). All patients presented with cardiac arrest or ventric ular tachycardia. During follow-up of 10 +/- 6 months (range 1 to 19), 70% of the 20 patients with antitachycardia pacing activated used the feature for spontaneous ventricular tachycardia. The antitachycardia pacing parameters were reprogrammed 20 times in 15 patients. Two thous and six hundred thirty-eight of 2,675 (98%) antitachycardia pacing att empts successfully terminated spontaneous tachyarrhythmias. Low-energy cardioversion or defibrillation terminated tachyarrhythmias in patien ts where pacing was unsuccessful. One hundred forty-eight episodes of tachycardia were successfully treated directly by shocks in 16 of 46 p atients (35%). There were no deaths due to device failure. This initia l single-center clinical experience suggests that the PCD, Cadence and VENTAK PRx are all safe and effective tiered therapy devices for the treatment of malignant ventricular arrhythmias. Antitachycardia pacing successfully terminated most episodes of ventricular tachycardia; in patients with this feature activated, it was used frequently but requi red reprogramming to achieve high levels of success.