VENTRICULAR FIBRILLATION OF LONG DURATION ABOLISHED BY ELECTRIC SHOCK

1947 ◽  
Vol 135 (15) ◽  
pp. 985 ◽  
Author(s):  
C. S. BECK
Keyword(s):  
Ventricular Fibrillation ◽  
Electric Shock ◽  
Long Duration

Abstract 591: Can Waveform Characteristics Predict Defibrillation to a Perfusing Rhythm in Short Versus Prolonged Ventricular Fibrillation in a Swine Model?

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Julia H Indik ◽  
Mathias Zuercher ◽  
Karl B Kern ◽  
Ronald W Hilwig ◽  
Robert A Berg
Keyword(s):  
Logistic Regression ◽  
Ventricular Fibrillation ◽  
Short Duration ◽  
Important Determinant ◽  
Swine Model ◽  
Median Frequency ◽  
Chest Compressions ◽  
Long Duration ◽  
Spectral Area ◽  
Minute Duration

It is known that defibrillation of ventricular fibrillation (VF) to a perfusing rhythm (ROSC) is more likely to occur in VF of short duration. It is unknown whether ROSC can be predicted by waveform characteristics in VF of short compared to long duration, apart from a consideration of time alone. VF was untreated for 2 minutes (N=10) or 8 minutes (N=10) in normal swine, after which a defibrillation shock was applied. Chest compressions for two minutes were allowed following but not prior to the shock to achieve a perfusing rhythm (ROSC). VF was analyzed from needle electrodes prior to the shock for amplitude spectral area (AMSA), slope, median frequency and bandwidth. Predictors of ROSC were determined by logistic regression. In VF of 2 minute duration 7 out of 10 swine achieved ROSC compared to 2 out 10 swine with VF of 8 minutes (P=0.025) and time was a significant predictor of ROSC (P=0.033). AMSA was significantly higher at 2 minutes (75 ± 18 mV-Hz) compared to 8 minutes (56±11 mV-Hz, p=0.007) as was slope (3.5±1 vs 2.6±0.5 mV/s, p=0.015). Bandwidth was slightly increased from 2.2±0.6 Hz at 2 minutes to 2.8±0.8 Hz at 8 minutes,(p=0.048), while median frequency was similar. However, no waveform characteristic was a significant predictor of ROSC, with substantial overlap in distributions between animals with and without ROSC. Duration of VF is an important determinant of the likelihood of achieving ROSC with defibrillation. Particularly in VF of short duration, VF waveform characteristics do not add to the predictability of achieving ROSC even though they may demonstrate a significant time evolution.

Abstract 2645: Longer Ventricular Fibrillation Detection Duration Does Not Increase Rate of Undersensing: Results from the PREPARE Study

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Stephen Moore ◽  
Richard Stern ◽  
Mark L Brown ◽  
Brooke M Heubner ◽  
Jim W Johnson
Keyword(s):  
Primary Prevention ◽  
Ventricular Fibrillation ◽  
Shock Delivery ◽  
Long Duration ◽  
Increase Rate ◽  
The Times ◽  
Over Time

Background: The PREPARE study was designed to evaluate ICD detection and therapy parameters strategically selected to safely reduce all-cause shocks in patients with primary prevention indications by treating only truly sustained fast VT/VF. Electrophysiologic properties have been shown to deteriorate during long-duration VF episodes. There was concern that electrogram deterioration might result in increased undersensing (US) and delayed detection of VF. In this analysis we compared the rate of US between episodes detected with shorter (number of intervals to detect (NID) =12/16) and longer (NID=30/40) detection settings to assess whether delayed detection times for VF increased the rate of US. Methods: All induced VT/VF episodes from PREPARE patients programmed to NID 12/16 or 30/40 and sensitivity 1.2 mV were included in the analysis. US was determined automatically from the stored episode record. The numbers of US and the times from onset through initial detection and from detection to shock were computed. The rates of US over time were compared between the shorter and longer NIDs using a GEE analysis with time as the offset. Results: Seven hundred fifty six VF inductions in 432 patients from the PREPARE study were included in the analysis. There were 319 VF inductions (180 pts) with NID 12/16 and 437 VF inductions (261 pts) with NID 30/40. The average time from VF onset to shock increased from 6.0 to 9.5 seconds with the longer VFNID with no evidence of an increase in the rate of US over time. Conclusion: The longer NID delayed shock delivery by an average of 3.5 seconds but did not result in an increased rate of undersensing.

scholarly journals Intramural optical mapping of Vm and Cai2+ during long-duration ventricular fibrillation in canine hearts

2012 ◽  
Vol 302 (6) ◽  
pp. H1294-H1305 ◽  
Author(s):  
Wei Kong ◽  
Raymond E. Ideker ◽  
Vladimir G. Fast
Keyword(s):  
Ventricular Fibrillation ◽  
Action Potential ◽  
Short Duration ◽  
Action Potential Duration ◽  
Cycle Length ◽  
The Other ◽  
Membrane Voltage ◽  
Long Duration ◽  
Intracellular Ca ◽  
Rapid Pacing

Intramural gradients of intracellular Ca2+ (Cai2+) Cai2+ handling, Cai2+ oscillations, and Cai2+ transient (CaT) alternans may be important in long-duration ventricular fibrillation (LDVF). However, previous studies of Cai2+ handling have been limited to recordings from the heart surface during short-duration ventricular fibrillation. To examine whether abnormalities of intramural Cai2+ handling contribute to LDVF, we measured membrane voltage ( Vm) and Cai2+ during pacing and LDVF in six perfused canine hearts using five eight-fiber optrodes. Measurements were grouped into epicardial, midwall, and endocardial layers. We found that during pacing at 350-ms cycle length, CaT duration was slightly longer (by ≃10%) in endocardial layers than in epicardial layers, whereas action potential duration (APD) exhibited no difference. Rapid pacing at 150-ms cycle length caused alternans in both APD (APD-ALT) and CaT amplitude (CaA-ALT) without significant transmural differences. For 93% of optrode recordings, CaA-ALT was transmurally concordant, whereas APD-ALT was either concordant (36%) or discordant (54%), suggesting that APD-ALT was not caused by CaA-ALT. During LDVF, Vm and Cai2+ progressively desynchronized when not every action potential was followed by a CaT. Such desynchronization developed faster in the epicardium than in the other layers. In addition, CaT duration strongly increased (by ∼240% at 5 min of LDVF), whereas APD shortened (by ∼17%). CaT rises always followed Vm upstrokes during pacing and LDVF. In conclusion, the fact that Vm upstrokes always preceded CaTs indicates that spontaneous Cai2+ oscillations in the working myocardium were not likely the reason for LDVF maintenance. Strong Vm-Cai2+ desynchronization and the occurrence of long CaTs during LDVF indicate severely impaired Cai2+ handling and may potentially contribute to LDVF maintenance.

The potential of electric shock for humane trapping of brushtail possums, Trichosurus vulpecula

1994 ◽  
Vol 21 (1) ◽  
pp. 49 ◽  
Author(s):  
ID Dix ◽  
SE Jolly ◽  
LS Bufton ◽  
AI Gardiner
Keyword(s):  
Ventricular Fibrillation ◽  
Electric Shock ◽  
Energy Levels ◽  
High Energy ◽  
Cardiac Response ◽  
Brushtail Possum ◽  
Electric Device ◽  
In The Wild ◽  
Very High Energy ◽  
Major Pest

The Australian brushtail possum is a major pest in New Zealand, and a device to kill possums in the wild by electric shock has been proposed. This investigation was to determine the best waveform and energy level for an electric device to humanely kill possums. The criterion set was a shock which would cause ventricular fibrillation and result in irreversible unconsciousness within a few minutes. Anaesthetised possums were shocked with sinusoidal alternating currents, direct current bursts and impulse waveforms of varying intensities and durations. An electrocardiogram was used to monitor the cardiac response. Although sinusoidal waveforms of a long duration did disrupt the heartbeat and might result in death, even shocks of very high energy levels did not consistently result in ventricular fibrillation. The use of electricity to trap and kill possums appears unacceptable on humanitarian grounds.

scholarly journals The Importance of Purkinje Activation in Long Duration Ventricular Fibrillation

2014 ◽  
Vol 3 (1) ◽  
Author(s):  
Jian Huang ◽  
Derek J. Dosdall ◽  
Kang‐An Cheng ◽  
Li Li ◽  
Jack M. Rogers ◽  
...  
Keyword(s):  
Ventricular Fibrillation ◽  
Long Duration

Direction of Human Motor Responses by Men and Women to Aversive Stimulation

2000 ◽  
Vol 90 (2) ◽  
pp. 415-422 ◽  
Author(s):  
Farzaneh Pahlavan ◽  
Daniel Duda ◽  
Philippe Bonnet
Keyword(s):  
Electric Shock ◽  
Aversive Stimulation ◽  
Intraindividual Variability ◽  
Voluntary Movements ◽  
Prior Specification ◽  
Long Duration ◽  
On Line ◽  
Human Motor ◽  
Neutral Tone ◽  
Spatially Oriented

The frequency of extensions and flexions of the arms of 12 men and 12 women (ages 20–30 years) responding to a neutral tone or to an electric shock was recorded. Subjects had to choose between pushing or pulling a lever upon receipt of an acoustic signal which was paired or unpaired with an electric shock. They were instructed to perform either long duration movements, allowing for on-line control of the execution, or short duration movements with prior specification of amplitude. Regardless of duration of movements, the aversive signal increased the frequency of extensions and intraindividual variability of choices of the men but decreased the frequency of extensions and intraindividual variability of choices of the women. These findings show that stimuli such as pain or fear automatically elicit patterns of terminal motor states corresponding to fight or flight, initiating processes of preparation of spatially oriented movements which are automatic and sex-typed and impair the use of the terminal cues for simultaneous preprogrammed voluntary movements.

scholarly journals Electrophysiological Deterioration During Long-Duration Ventricular Fibrillation

Circulation ◽  
2000 ◽  
Vol 102 (23) ◽  
pp. 2886-2891 ◽  
Author(s):  
Oscar H. Tovar ◽  
Janice L. Jones
Keyword(s):  
Ventricular Fibrillation ◽  
Long Duration
Sign in / Sign up

Export Citation Format

Share Document