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Updated: Sep 30, 2025

A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation
Published on: February 28, 2012
Efficacy of defibrillator pads placement during ventricular arrhythmias, a before and after analysis
Mikkel F Steinberg1, Jan-Aage Olsen2, David Persse3
1National Advisory Unit on Prehospital Emergency Medicine, Oslo University Hospital, Oslo, Norway; Department of Medicine, Ringerike Hospital, Vestre Viken HF, Norway.
Background:
European resuscitation guidelines describe several acceptable placements of defibrillator pads during resuscitation of cardiac arrest. However, no clinical trial has compared defibrillation efficacy between any of the different pad placements. Houston Fire Department emergency medical system (EMS) used anterior-posterior (AP) defibrillator pad placement before becoming a study site in the circulation improving resuscitation care trial (CIRC). During CIRC, Houston Fire EMS used sternal-apical (SA) pad placement.
Methods:
Data from electronic defibrillator records was compared between a pre-CIRC dataset and patients in the CIRC trial receiving manual cardiopulmonary resuscitation (CPR). Only shocks from patients with initial ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) were included. Measured outcome was defibrillation efficacy, defined as termination of VF/VT. The general estimatingequations model was used to study the association between defibrillation efficacy rates in the AP vs SA group.
Results:
In the pre-CIRC dataset, 207 included patients received 1023 shocks with AP pad placement, compared with 277 patients from the CIRC trial who received 1020 shocks with SA pad placement. There was no significant difference in defibrillation efficacy between AP and SA pads placement (82.1 % vs 82.2 %, p = 0.98).
Conclusion:
No difference was observed in defibrillation efficacy between AP and SA pad placement in this study. A randomized clinical trial may be indicated.
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Electrocardiogram Fundamentals
An electrocardiogram (ECG) is a diagnostic tool for identifying cardiac conditions such as arrhythmias, conduction abnormalities, and myocardial ischemia.
Definition
An electrocardiogram (ECG) visualizes the heart's electrical activity by tracing the electrical movement associated with each heartbeat on a graph or monitor. As the heart beats, an electrical wave passes through it, correlating with the cardiac cycle events.
Parts of an ECG
An ECG utilizes electrodes on the skin...
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