Clinical Information; How Does Biphasic Waveform Defibrillate - Progetti Rescue Life 9 Instructions For Use Manual

APPENDIX A

CLINICAL INFORMATION

Sudden cardiac arrest (SCA) associated with ventricular fibrillation (VF) remains a leading cause of
unexpected death in the Western world. It has been estimated that chances for survival from SCA decrease
approximately 7% to 10% with each passing minute and that survival rates after 12 minutes are only 2% to
5%.
The most common cause of SCA is ventricular fibrillation (VF), a lethal heart rhythm, and survival depends
on the rapid treatment called de-fibrillation, an electrical shock sent to the heart to resume normal and
healthy heart rhythm.
So early defibrillation is the sole definitive determinant of survival and is the key factor in cardiopulmonary
resuscitation. Currently, fewer than 5% of the 250,000 persons who experience out-of-hospital cardiac
arrest each year survive to hospital discharge.

HOW DOES BIPHASIC WAVEFORM DEFIBRILLATE?

For defibrillation to be successful, a sufficient amount of electrical current must be delivered to the heart
muscle. How to deliver the electrical current to the heart muscle is the core technique to defibrillate the
heart.
Successful defibrillation would be done when the cell membranes of the heart are "coated" with positive
ions on one side and negative ions on the other side, enough to depolarize nearly 100 percent of the
cardiac cells at the same instant. Optimal current is determined with the pressure (this means electric
Voltage) that controls what an amount of current can be pushed and the duration of time the current
flows. This defibrillation current is commonly described in joules of energy. Energy is a measure of the
amount of current, voltage, and duration of time the current flows.
When the Defibrillation shock is delivered, current flow is affected by transthoracic impedance, the body's
resistance from electrode to heart. Impedance is dependent on the anatomy of the chest, skin surface, air
in the chest, hair, fat and bone, as well as the size and location of the defibrillation electrodes.
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