Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Preimplant Atrial Defibrillation Testing with a Temporary Catheter in Sheep (1997)
    Oxford, UK : Blackwell Publishing Ltd
    Pacing and clinical electrophysiology 20 (1997), S. 0 
    Details
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Prior to implantation of an atrial defibrillator, its effectiveness should be tested in each patient. A new catheter design for temporary use with electrodes for atrial defibrillation, electrogram sensing, and pacing was tested in this study. Atrial defibrillation thresholds defined using this temporary catheter were compared to the ones defined by catheters intended for chronic use with an implantable atrial defibrillator. Atrial defibrillation threshold was determined in six sheep using both types of catheters. Each animal was subjected to studies on 2 consecutive days. On the first day, shocks were applied between two of the temporary catheters. On the following day, permanent leads were inserted and atrial defibrillation threshold was redetermined. In both cases, defibrillation electrodes were positioned in the same heart location with one electrode in the distal coronary sinus and the second electrode in the right atrium. Atrial defibrillation threshold was obtained using 10 V increments or decrements to determine the lowest shock intensity needed to defibrillate the atria. Threshold was defined as the shock intensity at which 20 shock percent success was at or between 15 % and 85%. Statistical analysis showed no significant difference (P 〈 0.05) between atrial defibrillation threshold energy (0.53 J vs 0.55 J), voltage (122 V vs 120 V) or current (2.2 A vs 2.6 A) measured with the temporary catheters and the permanent leads, respectively. These data indicate that temporary catheters can be used for efficacy testing prior to implant of an atrial defibrillator, and that they predict atrial defibrillation threshold adequately for chronic leads.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-8159.1997.tb03562.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Electrocardiograms from the Turtle to the Elephant that Illustrate Interesting Physiological Phenomena (2002)
    Oxford, UK : Blackwell Futura Publishing, Inc.
    Pacing and clinical electrophysiology 25 (2002), S. 0 
    Details
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: GEDDES, L.A. Electrocardiograms From the Turtle to the Elephant that Illustrate Interesting Physiological Phenomena. This article describes a collection of ECGs from many species obtained over the past 50 years. Presented are ECGs of species in which the pacemaker is a separate contractile chamber with its own action and recovery potentials. In such species, pacemaker atrial and AV block can be produced. Shortening of the atrial refractory period and the negative inotropic effect can be produced by vagal stimulation. The cardiac electrogram and stroke volume are recorded from the turtle heart. The ECG and respiration were recorded from the snake. ECG records were obtained from the anesthetized and decapitated housefly. ECG records of the rabbit show slowing when the nose encountered irritating vapors. Records from a dog with atrial fibrillation exhibit rhythmic fibrillation frequency changes correlated with respiration. In addition, in a morphinized dog with atrial fibrillation, impulses crossed the AV node only during inspiration. The ECGs of a cow and camel exhibit long P-R intervals and biphasic P waves. Finally the elephant ECG shows a clear U wave following the T wave.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1460-9592.2002.01762.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The Paradox in Using Electrically Stimulated Skeletal Muscle to Pump Blood (1997)
    Oxford, UK : Blackwell Publishing Ltd
    Pacing and clinical electrophysiology 20 (1997), S. 0 
    Details
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: For over four decades, various methods have been described for the use of electrically stimulated skeletal muscle to pump blood. To date, there has been no way of predicting the efficacy or long-term pumping capabilities of these methods. This article reviews the basic physiological properties of skeletal muscle and relates them to the blood pumping task and illustrates the paradox, namely a high preload is needed for a forceful contraction, but a high prolonged preload produces muscle ischemia and early fatigue. However, the high preload is only required just before muscle contraction. Two methods are described to attain the high preload and high muscle capillary blood flow.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-8159.1997.tb03607.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Ventricular Fibrillation Frequency (2005)
    350 Main Street , Malden , MA 02148-5018 , USA and 9600 Garsington Road , Oxford OX4 2DQ , UK . : Blackwell Science Inc
    Pacing and clinical electrophysiology 28 (2005), S. 0 
    Details
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: Ventricular-fibrillation (VF) wave frequency is known to decrease with prolonged, untreated VF. VF wave frequency is used as an algorithm to identify VF in AEDs and ICDs; yet the nature of the frequency change is not appreciated. Methods: In this study, anesthetized pigs were used and VF was induced electrically. VF wave frequency was measured each second during VF for periods up to 200 sec. Defibrillation was achieved with transchest electrodes. VF wave frequency was plotted for each second during VF. In 2 animals, CPR was applied and VF wave frequency was measured. Results: In all cases VF wave frequency decreased with increasing duration of VF. At the onset of VF, the VF wave frequency ranged from 5 to 12/sec. A plot of the normalized ratio of VF wave frequency during fibrillation to the VF frequency at induction decreased to between 0.1 and 0.8 of the initial frequency. In one of the animals, VF was initiated, CPR was provided and the VF wave frequency was measured over a 200-second period. Then, the procedure was repeated without CPR. Beyond 130 seconds, the VF frequency with CPR was higher than that without CPR, indicating myocardial oxygenation. Conclusion: Those who use VF wave frequency to identify the presence of VF should be aware of the nature of the VF wave frequency decrease with the passage of time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1540-8159.2005.00166.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Tumpy, the Camel, and the Electrical Dose Concept for Ventricular Defibrillation (2003)
    350 Main Street , Malden , MA 02148-5018 , USA , and 9600 Garsington Road , Oxford OX4 2DQ , UK . : Blackwell Futura Publishing, Inc.
    Pacing and clinical electrophysiology 26 (2003), S. 0 
    Details
    ISSN: 1540-8159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1460-9592.2003.t01-1-00223.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...