Sudden Cardiac Arrest

Q: What is sudden cardiac arrest?

A: SCA is a sudden and unexpected abnormality of the heart’s electrical system which causes the heart to stop beating normally. When one occurs, blood stops flowing properly and the person collapses. The only way to restore their heart rhythm is by administering a shock immediately. Anyone can deliver the shock using an AED.

Q: Is an SCA the same as a heart attack?

A: No. A heart attack (myocardial infarction) occurs when the heart’s blood supply is reduced or blocked. The heart muscle becomes injured or may start to die. During a heart attack, the victim is conscious. In fact, the victim may complain about symptoms.

An SCA is an electrical problem in the heart which causes the heart to beat in an irregular, inefficient manner. Since the blood can’t circulate to the brain, the victim passes out.

A heart attack victim has a pulse but an SCA victim does not.

You don’t have to remember these distinctions. When the AED instructs you to put the pads on the victim, it will sense the heart rhythm and determine the best steps to take, giving you guidance all along the way.

Q: What is defibrillation?

A: Defibrillation is giving an electric shock to the heart. The shock resets the heart’s electrical system and allows a normal heart rhythm to return.

An automated external defibrillator (AED) is a device that delivers that shock. It analyzes the heart rhythm and if necessary, provides instructions on how to deliver it.

Q: When should I use an AED?

A: If a person collapses or loses consciousness, and either doesn’t have a pulse or isn’t breathing properly, you need to intervene. Even if he or she is gasping for breath or having seizures, if the person is unconscious, use the AED.

Don’t worry about diagnosing the victim correctly. The Philips AED will analyze the heart rhythm and tell you to deliver a shock, if and only if the victim needs it. All you need to do is open the AED and follow the clear, calm voice instructions. You’ll be told how put the pads on the victim so the machine can detect the heart rhythm.

Q: How do I know how to use an AED?

A: Philips AEDs are designed to be very simple to use. Once you open the AED, a clear, calm voice walks you through the entire rescue process as you do it—at your own pace. The device can tell what step you’re on and will adjust its instructions accordingly.

The most important thing you need to do is act. If there is an AED nearby, find it and open it. The heart needs to be restored to a normal rhythm within 3 – 5 minutes for the best chance of survival.

Q: Can I hurt someone?

A: No, not if you follow the instructions from the AED. AEDs are designed to help people whose hearts have stopped working effectively. If the AED instructs you to deliver a shock, the person you are helping is already clinically dead. Your actions can only help. You may be able to restore a healthy heart rhythm.

Q: Why do I not just wait for a professional responded to arrive?

A: The best chance to survive a sudden cardiac arrest is if the person is shocked within 3 – 5 minutes. Often, emergency responders can’t arrive within that small time frame.

Q: Do I need to get training to use an AED?

A: Philips AEDs are designed so that anyone can use them immediately. However, training is still a good idea. The more familiar you are with the signs of a SCA and the use of the AED, the more likely you are to be calm and helpful in an actual emergency.

Q: Which is better—performing CPR or using an AED? 

A: Cardio pulmonary resuscitation (CPR) is one way to help a victim of SCA. It uses chest compressions and may include rescue breathing.

Both cardio pulmonary resuscitation (CPR) and AEDs have a role in saving lives. Performing either is better than doing nothing. Using both CPR and an AED gives the victim an even greater chance of survival.


Q: What if I do it wrong?

A: The AED is designed to tell you exactly what you need to do. It keeps pace with what you are doing and adapts its instructions so that it doesn’t overwhelm, run ahead, or slow you down. If necessary, it will repeat the prompts, rephrasing them or adding additional instruction to help you understand.

Q: What if I don’t know the proper technique?

A: Philips AEDs are designed with Life Guidance, a simple step-by-step process designed to help you act confidently and decisively. Life Guidance acts as your personal coach to guide you through a cardiac emergency, including detailed CPR coaching. If needed, the prompts will automatically be repeated or rephrased, and may include additional instructions to help you understand.

Q: How soon must the defibrillator shock be administered?

A: The person’s best chance of survival is to receive that shock within five minutes of collapse. A defibrillator will not save every person who experiences SCA, but more lives could be saved if those affected were reached more quickly. Your quick response makes a real difference. Philips AED’s also have patented Quick Shock, HeartStart is among the fastest in its class at delivering shock treatment after CPR, typically in just eight seconds.

Q: How do I know if a shock is needed?

A: The defibrillator assesses the patient’s heart rhythm. If a shock is advised, it directs you to press the flashing orange Shock button. If the defibrillator determines that a shock is not called for, you cannot deliver a shock, even if you press the Shock button.

Q: What if I don’t know where to put the pads?

A: The SMART Pads cartridge contains two adhesive pads that have pictures on them to show you where to place the pads on the person’s bare skin, and voice instructions will remind you to look at the pictures. The pads are “smart” because they sense when they have been removed from the cartridge, peeled from their liners, and applied to the patient, causing the voice instruction to adjust to your actions.


Q: How does HeartStart assess heart rhythm?

A: HeartStart includes highly proven Philips technology for heart rhythm assessment, called SMART Analysis. SMART Analysis is a sophisticated algorithm that simultaneously evaluates several attributes of a person's heart rhythm to determine if the rhythm is shockable.

Q: How does HeartStart know how much energy to deliver?

A: A technology called SMART Biphasic Impedance Compensation helps HeartStart deliver the right amount of current and energy. Smart Biphasic is the first biphasic therapy with sufficient evidence to be classed “standard of care” and “intervention of choice” by the American Heart Association. SMART Analysis and SMART Biphasic’s effectiveness are backed by over 40 published, peer-reviewed studies.1


Q: Is training available?

A: Yes. A special training SMART Pads cartridge can be installed in the defibrillator. It disables the defibrillator’s ability to shock, while walking you through patient care scenarios. We also offer easily accessible, online training that discusses everything from setting up an AED program to replacing your defibrillator’s battery.


1) Philips Medical Systems. SMART Biphasic Studies, listed alphabetically by study author:http://www.healthcare. philips.com/ au_en/products/resuscitation/biphasic_ technology/references.wpd