Low-tilt monophasic and biphasic waveforms compared with standard biphasic waveforms in the transvenous defibrillation of ventricular fibrillation.
Pacing Clin Electrophysiol
; 37(3): 279-89, 2014 Mar.
Article
em En
| MEDLINE
| ID: mdl-24102186
ABSTRACT
BACKGROUND:
Commercially available implantable defibrillators utilize a high-tilt waveform. Studies in atrial fibrillation and transthoracic defibrillation of ventricular fibrillation (VF) have shown improved defibrillation efficacy using low-tilt (LT) waveforms. We investigated the feasibility, efficacy, and safety of a LT waveform in the transvenous defibrillation of VF and hypothesized that it would be more efficacious than standard tilted biphasic (STB) waveforms. METHODS ANDRESULTS:
The investigation was performed in four phases in a porcine model an efficacy study of LT monophasic waveforms (n = 9), an efficacy study of LT biphasic waveforms (n = 9), a comparison study between the most successful LT waveforms and clinically available STB waveforms (n = 15), and a safety study (n = 9). A total of 1,056 shocks were delivered (phase 1 288, phase 2 288, phase 3 480). The LT biphasic 8/4-ms waveform was significantly more likely to successfully defibrillate than the LT monophasic and STB waveforms with an odds ratio of 122.3 (95% confidence interval 32.5, 460.2, P < 0.001). The calculated defibrillation threshold (E50) for the LT 8/4-ms waveform was 12.7 J compared to 43.5 J and 45.5 J for STB waveforms 6/6 ms and 8/4 ms, respectively, and 47.7 J for LT 12-ms waveform. The LT 8/4-ms waveform had no lasting detrimental effect on cardiac function, and any transient hemodynamical or biochemical changes observed were comparable to those observed with STB waveforms.CONCLUSION:
LT waveforms are effective and appear safe in transvenous defibrillation in a porcine model of VF. The LT biphasic 8/4-ms waveform is more efficacious than conventional waveforms.Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Fibrilação Ventricular
/
Terapia Assistida por Computador
/
Cardioversão Elétrica
/
Diagnóstico por Computador
/
Eletrocardiografia
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Pacing Clin Electrophysiol
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Reino Unido