Preliminary Clinical Results of a Biphasic Waveform and an RV Lead System

• Published in: Pacing and clinical electrophysiology 1999-04, Vol.22 (4), p.594-599
• Main Authors: MEHDIRAD, ALI A., LOVE, CHARLES J., STANTON, MARSHALL S., STRICKBERGER, S. ADAM, DUNCAN, JAMES L., KROLL, MARK W.
• Format: Article
• Language: English
• Subjects: Cardiac Output, Low - complications; Cardiomyopathies - complications; Cardiotonic Agents - therapeutic use; Coronary Disease - complications; defibrillation threshold; Defibrillators, Implantable; Electric Countershock - methods; Equipment Design; Evaluation Studies as Topic; Female; Follow-Up Studies; Humans; implantable defibrillator; Male; Middle Aged; steroid eluting lead; Tachycardia, Ventricular - therapy; transvenous lead; Ventricular Fibrillation - therapy
• ISSN: 0147-8389; 1540-8159
• DOI: 10.1111/j.1540-8159.1999.tb00500.x

Biphasic defibrillation waveforms have provided a reduction in defibrillation thresholds in transvenous ICD systems. Although a variety of biphasic waveforms have been tested, the optimal pulse durations and tilts have yet to be identified. A multicenter clinical study was conducted to evaluate the performance of a new ICD biphasic waveform and new RV active fixation steroid eluting lead system. Fifty‐three patients were entered into the study. Mean age was 63 years with a mean ejection fraction of 36.8%. Primary indication for implantation was monomorphic ventricular tachycardia alone (54.7%). Forty‐eight patients (90.6%) were implanted with an RV shocking lead and active can alone as the anodal contact. The ICD can was the cathode. In four cases (7.5%), an additional SVC or CS had was used due to a high DFT with the RV lead alone. In an additional case, a chronic SVC lead was used although the RV‐Can DFT was acceptable. DFT for all cases at implant was 9.8 ± 3.7 J. Repeat testing at 3 months for a subset of patients showed a reduction in DFT (7.4 ± 3.0 J), P value = 0.03. Sensing and pacing characteristics of the RV lead system remained excellent during the study period (acute 0.047 ± 0.005 ms at 5.4 V and 9.9 ± 6.2 mV R wave; chronic 0.067 ± 0.11 ms at 5.4 V and 9.3 ± 5.4 mV R wave). It is concluded that this lead system provides good acute and chronic sensing and pacing characteristics with good DFT values in combination with this waveform.