Sudden cardiac arrest (SCA) comes on quickly. A malfunction of the heart’s electrical system causes it to unexpectedly and abruptly stop beating properly. Often it can result in an abnormal heart rhythm called ventricular fibrillation (VF) that can cause the heart to quiver and pump blood ineffectively.
Symptoms of SCA include sudden collapse, loss of consciousness, loss of pulse, gasping, and shortness or loss of breath. The only effective treatment for VF is an electrical shock administered by an automated external defibrillator (AED) and high-quality cardiopulmonary resuscitation (CPR).
SCA is often confused with a heart attack, but they are not the same. During a heart attack, blood supply to the heart muscle is severely reduced or blocked. Symptoms of a heart attack can vary, sometimes coming on suddenly and sometimes starting slowly and persisting for hours, days, or weeks.
Sudden cardiac arrest (SCA) occurs when an electrical malfunction of the heart causes it to suddenly stop beating.
SCA is not a heart attack. A heart attack occurs when blood flow to the heart is impeded due to a blocked artery.
There are two important ways you can help:
High-quality CPR has a big impact on a victim's outcome.
Not every victim will need a defibrillating shock, but all victims will need high-quality CPR. It has the potential to convert a non-shockable rhythm into a shockable one and is essential to continue moving blood throughout the body to protect vital organs.
When an SCA victim has a shockable rhythm, CPR must begin immediately after the shock is delivered to support the heart as it tries to restore a normal rhythm. Without CPR, a shock alone may be ineffective.
1 Link MS, et al. Circulation. 2010;122:S706.