Objectives: The effects of two clinically available biphasic waveforms on the success of defibrillation and postresuscitation myocardial dysfunction after prolonged ventricular fibrillation were compared with two newly designed dual-path sequential and simultaneous rectilinear biphasic waveforms. Defibrillation via sequential pulses and encircling, overlapping multiple pathway may depolarize a larger myocardial mass and facilitate transthoracic defibrillation.
Design: Animal study.
Setting: Experimental laboratory.
Subjects: Thirty-two 40 +/- 3 kg pigs.
Interventions: Ventricular fibrillation was ischemically induced in 32 pigs. After 7 mins of untreated ventricular fibrillation, cardiopulmonary resuscitation was initiated and continued for 5 mins. Animals were then randomized to receive up to three shocks with a) single-path rectilinear biphasic waveform; b) single-path biphasic truncated exponential waveform; c) dual-path rectilinear biphasic sequential defibrillation; or d) dual-path rectilinear biphasic simultaneous defibrillation.
Measurements And Main Results: Rectilinear biphasic, dual-path sequential defibrillation, and simultaneous defibrillation had significantly fewer shocks (1.1 +/- 0.4, 1.4 +/- 0.5, 1.3 +/- 0.7, respectively) before restoration of spontaneous circulation than biphasic truncated exponential waveform (2.6 +/- 1.4, p < .005) and less postresuscitation myocardial dysfunction (p < .05). Also, dual-path sequential defibrillation had higher postresuscitation ejection fraction than rectilinear biphasic and dual-path simultaneous defibrillation (p < .005).
Conclusions: The energy requirements for terminating ischemically induced ventricular fibrillation were significantly lower and minimized early postresuscitation myocardial dysfunction in the rectilinear biphasic, dual-path sequential defibrillation, and simultaneous defibrillation than the biphasic truncated exponential waveform. Dual-path sequential defibrillation had less postresuscitation myocardial dysfunction than rectilinear biphasic and dual-path simultaneous defibrillation, but at 72 hrs these differences were no longer significant.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1097/01.CCM.0000248881.15376.B4 | DOI Listing |
Europace
February 2023
Department of Medicine, McMaster University, Hamilton, Ontario L8P 1H6, Canada.
Aims: Electrical cardioversion is commonly used to restore sinus rhythm in patients with atrial fibrillation (AF), but procedural technique and clinical success vary. We sought to identify techniques associated with electrical cardioversion success for AF patients.
Methods And Results: We searched MEDLINE, EMBASE, CENTRAL, and the grey literature from inception to October 2022.
Resuscitation
March 2016
Instituto de Cardiologia do Rio Grande do Sul, Fundação Universitária de Cardiologia (ICFUC), Porto Alegre, RS, Brazil.
Objectives: Conduct a systematic review of the literature to compare the efficacy of different biphasic and monophasic shock waveforms technologies for transthoracic cardioversion of Atrial Fibrillation (AF).
Methods: We searched PubMed, EMBASE, The Cochrane Library, LILACS and ClinicalTrials.gov databases for randomized clinical trials comparing two or more defibrillation waveforms when performing elective transthoracic cardioversion of AF.
Sensors (Basel)
September 2015
Centre for Advanced Cardiovascular Research, Ulster University, BT37 0QB, UK.
A wireless powered implantable atrial defibrillator consisting of a battery driven hand-held radio frequency (RF) power transmitter (ex vivo) and a passive (battery free) implantable power receiver (in vivo) that enables measurement of the intracardiac impedance (ICI) during internal atrial defibrillation is reported. The architecture is designed to operate in two modes: Cardiac sense mode (power-up, measure the impedance of the cardiac substrate and communicate data to the ex vivo power transmitter) and cardiac shock mode (delivery of a synchronised very low tilt rectilinear electrical shock waveform). An initial prototype was implemented and tested.
View Article and Find Full Text PDFResuscitation
October 2014
School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing, China. Electronic address:
Objective: Defibrillation current has been shown to be a clinically more relevant dosing unit than energy. However, the effects of average and peak current in determining shock outcome are still undetermined. The aim of this study was to investigate the relationship between average current, peak current and defibrillation success when different biphasic waveforms were employed.
View Article and Find Full Text PDFResuscitation
November 2013
AREU Azienda Regionale Emergenza Urgenza (Lombardia Regional Emergency Service), Italy. Electronic address:
Aim: Assessment and comparison of the electrical parameters (energy, current, first and second phase waveform duration) among eighteen AEDs.
Method: Engineering bench tests for a descriptive systematic evaluation in commercially available AEDs. AEDs were tested through an ECG simulator, an impedance simulator, an oscilloscope and a measuring device detecting energy delivered, peak and average current, and duration of first and second phase of the biphasic waveforms.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!