Sudden cardiac arrest (SCA) is an event caused by a problem with the heart’s “electrical” system. SCA occurs when the heart suddenly stops beating. The heart’s electrical system sends signals to the heart to beat much too fast. The heart cannot beat that fast, so the heart muscle just quivers. Blood and oxygen do not reach vital organs like the brain. Then it stops altogether. The heart needs immediate treatment from an electrical shock (defibrillation) to restart the electrical system. If SCA is not treated within 7-10 minutes, it leads to sudden cardiac death.
Figure 1: Normal heart with ventricles filling with blood, SA node initiates the heartbeat
Figure 2: Normal heart with electrical signal spreading to the ventricles causing them to contract and pump blood out of the heart.
Figure 3: Normal heart with blood being pumped out of the heart.
Figure 4: Heart undergoing sudden cardiac arrest. Abnormal electrical signals and disorganized beating cause the heart to stop.
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