Related Experiment Videos
Clinical efficacy and safety of the new cardioverter defibrillator systems
H J Trappe1, H Klein, H G Fieguth
1Department of Cardiology, University Hospital Hannover, Germany.
Insights
Biphasic implantable cardioverter defibrillators (ICDs) demonstrated a lower defibrillation threshold compared to monophasic ICDs in patients with ventricular tachycardia or fibrillation. This suggests improved efficacy for biphasic ICDs in managing life-threatening arrhythmias.
Area of Science:
- Cardiology
- Biomedical Engineering
- Medical Devices
Background:
- Implantable cardioverter defibrillators (ICDs) are crucial for managing life-threatening ventricular arrhythmias.
- Third-generation ICDs offer advancements in shock waveform technology.
Purpose of the Study:
- To evaluate the clinical efficacy and safety of new third-generation monophasic versus biphasic ICDs.
- To compare defibrillation thresholds and arrhythmia management between the two ICD types.
Main Methods:
- A study involving 38 patients with ventricular tachycardia (VT) or fibrillation (VF).
- Patients were divided into two groups: Group I received monophasic ICDs, and Group II received biphasic ICDs.
- Intraoperative defibrillation thresholds for induced VT and VF were measured.
Main Results:
- The mean defibrillation threshold was significantly lower for biphasic ICDs (Group II) compared to monophasic ICDs (Group I) for both induced VT and VF (P < 0.01).
- During a mean follow-up of 12 months, 11% of patients died.
- Antitachycardia pacing (ATP) successfully terminated 78% of arrhythmia events; however, 7% of events were not interrupted by ATP.
Conclusions:
- Biphasic ICDs exhibit a lower defibrillation threshold, indicating potentially greater efficacy in terminating ventricular arrhythmias.
- While ATP is effective, a significant percentage of events required ICD shocks as a primary therapy, highlighting the need for optimized device programming.
Abstract:
Clinical efficacy and safety of two new third-generation implantable cardioverter defibrillators (ICD) were studied in 38 patients with ventricular tachycardia (VT) or fibrillation (VF). There were 31 patients with coronary disease, three patients with right ventricular dysplasia, one patient with dilated cardiomyopathy, and three patients with valvular disease. Twenty-four patients (group I) received an ICD with monophasic (Ventak PRx 1700, CPI) and 14 patients (group II) with biphasic shocks (Cadence V 100, Ventritex). Intraoperatively, the mean defibrillation threshold was significantly lower in group II than in group I, both in patients with induced VT (group I 11.0 +/- 6.3 joules; group II 5.8 +/- 1.3 joules) (P < 0.01) and induced VF (group I 17.5 +/- 4.6 joules; group II 9.6 +/- 5.2 joules) (P < 0.01). During the mean follow-up of 12 +/- 7 months four patients (11%) died. 865 arrhythmia events (AE) occurred and were terminated by ATP (671 VTs, 78%). Acceleration of VTs was observed in 28 AE (3%) and ATP was unable to interrupt 58 AE (7%). ICD shocks were delivered as a first therapy in 108 AE (13%).