Survival rates during cardiac arrest are nearly nonexistent without chest compressions or defibrillation. Yet, if bystanders act quickly, the survival rate can soar to 74%. This is for patients in ventricular fibrillation. They must receive CPR and a defibrillator shock within three minutes of collapse.
Research highlights that swift action is vital for survival in emergencies. An AED nearby can save lives. Knowing the signs of cardiac arrest can help, too.
What is cardiac arrest?
Sudden cardiac arrest happens when the heart stops. This causes a loss of breathing and consciousness. It is usually due to a problem in the heart’s electrical system. It prevents the heart from pumping blood efficiently.
Sudden cardiac arrest is not a heart attack. A heart attack occurs when blood flow to part of the heart is blocked. A heart attack can, in some cases, disrupt the heart’s electrical system. This can cause sudden cardiac arrest.
Sudden cardiac arrest is life-threatening without prompt treatment. But survival is possible with immediate medical help. CPR and a defibrillator can significantly enhance survival chances until help arrives.
What is a defibrillator?
Sudden cardiac arrest kills over 350,000 people in the U.S. each year. It’s a leading cause of death. This equates to a life lost approximately every 90 seconds.
Sudden cardiac arrest occurs when the heart experiences an irregular heartbeat. This is often due to ventricular fibrillation or pulseless ventricular tachycardia.
The heart’s main job is to pump oxygen-rich blood. It does this with steady, regular beats. During a sudden cardiac arrest, the heart twitches instead of beating. This disrupts blood flow and deprives the brain of oxygen. Without oxygen, brain damage becomes irreversible, and death can occur within minutes.
Defibrillators, or AEDs, deliver an electric shock. This helps restore a normal heart rhythm. They treat erratic, rapid, or slow heart rhythms. They can also restart a stopped heart, bringing it back into sync.
Defibrillators have many uses. Automated external defibrillators (AEDs) are for people in sudden cardiac arrest. These devices are often in public areas. Anyone can use them in emergencies, without training.
Defibrillators are life-saving devices for those at high risk of dangerous arrhythmias. Surgeons place implantable cardioverter defibrillators (ICDs) inside the body. Wearable cardioverter defibrillators (WCDs) are external devices. They track and regulate heart rhythms.
A cardiac defibrillator is a medical device. It can be internal or external. It restores a normal heartbeat by shocking the heart.
The automated external defibrillator (AED) is the most commonly used device. It lets untrained bystanders defibrillate quickly, even without AED experience.
Modern AEDs are easy to use. You do not need any medical training to operate them.
How does defibrillation work?
In a healthy heart, electrical impulses trigger muscle contractions that pump blood efficiently. In ventricular fibrillation or tachycardia, the heart can’t contract. The signals are chaotic. An AED shocks the heart to reset its electrical activity, restoring normal function.
A defibrillator sends an electric shock to the heart. It depolarizes the heart and stops the arrhythmia. This brief reset pauses the heart’s electrical signals. Then, it returns to a normal rhythm.
Survival rates for cardiac arrest victims who got an AED shock before EMS arrived.
A study in the Journal of the American College of Cardiology examined 13,769 cardiac arrests outside hospitals. They were recorded between December 2005 and May 2007. It studied how bystander CPR and AED shocks, given before EMS arrived, affected survival rates to hospital discharge. Yet, the study did not record the time between the collapse and the defibrillation shock.
From the data analyzed, researchers concluded that:
- Only 7% of cardiac arrest victims survived hospital discharge. This was without bystander CPR or defibrillation shock.
- 9% of cardiac arrest victims survived hospital discharge. This was with bystander CPR but no AED shock.
- 38% of cardiac arrest victims, given CPR and an AED, survived hospital discharge.
In 13,769 out-of-hospital cardiac arrests, only 32% of victims got CPR from bystanders. 2.1% received an AED shock. Waiting for EMS, which usually arrives in 4 to 10 minutes, delayed care. This reduced survival rates.
Survival rates for cardiac arrest patients are under ideal circumstances.
In 2018, the journal Circulation published a study. It examined 49,555 out-of-hospital cardiac arrests in major U.S. and Canadian cities. The American Heart Association published the journal. The research examined how public AED use affected survival in some instances.
- The sudden cardiac arrest (SCA) occurred in public.
- The collapse was witnessed.
- The victim had an AED shockable rhythm—either ventricular fibrillation or pulseless ventricular tachycardia.
A study found that, under ideal conditions, AED use saved 66% of cardiac arrest victims. Without it, the rate was 43%. Victims shocked with a public AED were 2.62 times more likely to survive to hospital discharge. They were 2.73 times more likely to have good brain function than those treated only after EMS arrived. The study stressed that immediate help for cardiac arrest victims is vital. It can improve survival rates before responders arrive.
Time until defibrillation and survival rates.
The first studies examined how public access to defibrillation affected survival rates in cardiac arrests before responders arrived. Yet, extra research shows that reduced response times are crucial. This is especially true when non-medical responders have access to AEDs.
Lay Volunteers vs. EMS in Italy
A 2002 study in Circulation explored giving automated external defibrillators to untrained volunteers. The survey, conducted in Italy’s Piacenza region, involved 1,285 participants. The participants had no formal CPR training but received access to 39 AEDs.
In 22 months, volunteers responded to 143 cardiac arrests. They arrived 4.8 minutes faster than the 6.2-minute EMS response time. The study did not account for factors like shockable rhythms and seen collapses. But the quicker response tripled survival rates. Volunteers’ early defibrillation had a 10.5% survival rate. Traditional EMS had only a 3.3% rate.
Police vs. EMS in Florida
In Miami-Dade County, a study equipped police cars with AEDs. It aimed to reduce response times for out-of-hospital cardiac arrests. On average, police arrived in 4.88 minutes. That’s faster than the 7.64 minutes it took for EMS. As a result, the survival rate for victims treated by police reached 17.2%, compared to 9% for those treated by EMS.
Casino Security Guards Instructed in AED Use
A 2000 study in the New England Journal of Medicine explored giving casino security officers AEDs and training them to use them. The study provided valuable insights into survival rates in these settings. It controlled for ventricular fibrillation and response times.
In 105 patients with ventricular fibrillation, survival rates were 74%. The team delivered the first shock within three minutes of the collapse. When the shock occurred after three minutes, the rate was 49%. These findings stress the need to defibrillate within three minutes to maximize survival.
How does rapid defibrillation boost survival rates?
Rapid defibrillation dramatically improves survival. An AED’s electric shock interrupts the chaotic heart rhythm caused by cardiac arrest. This allows the heart to reset to a normal rhythm. This enables the heart to restore the flow of oxygen-rich blood throughout the body.
Without the heart pumping blood, the brain and organs deteriorate quickly. Chest compressions can only sustain limited oxygen circulation. A defibrillation shock is the only way to restart the heart. It lets the heart pump oxygen-rich blood again. This reduces the risk of brain damage and improves survival odds.
Why Aren’t Survival Rates 100%?
Early defibrillation boosts survival rates. An AED or advanced cardiac life support may fail to restart the heart, no matter how fast or effective its use.
An AED may not restore a normal heart rhythm. Some cardiac arrest victims have non-shockable rhythms, like pulseless electrical activity or asystole. Defibrillators work only on chaotic heart rhythms, not on absent or too orderly ones.
AED shock therapy may not revive those with severe health issues or heart problems. Yet, immediate chest compressions and defibrillation still offer the best chance of survival.
How Public Access Defibrillation Can Save Lives
Some victims may not survive. Yet, immediate CPR and fast defibrillation are best for survival after cardiac arrest. Many U.S. states now have laws for public access to defibrillation. They want to save more lives. So they can ensure that external defibrillators are in many locations.
You can often find easy-to-use portable defibrillators like the Philips HeartStart FRx or HeartSine Samaritan PAD 350P, 360P, or 450P in:
- Schools
- Colleges
- Gyms
- Swimming pools
- Shopping malls
- Dental offices
- Police stations
- Hospitals
In states with good access to AED programs, responders know of nearby AEDs. They can direct you to one quickly. It is vital to call 9-1-1 immediately if you see someone unresponsive or suddenly collapse.
What to Do If You Witness a Cardiac Arrest
If someone suddenly collapses and is unresponsive, act fast. If they aren’t breathing or only gasping, it’s urgent.
- Call 9-1-1 and send someone to get an AED.
- If it’s safe to approach, provide compression-only CPR (don’t give rescue breaths unless you are trained to do so).
- Attach the electrode pads, turn on the defibrillator, and follow the instructions. The AED will analyze the patient’s heart rhythm. If it detects a shockable heart rhythm, it will prompt you to shock the patient. The rhythms are ventricular fibrillation or pulseless ventricular tachycardia.
Survival rates from cardiac arrest decrease by 7–10% with every minute of delay in treatment. It is vital to know the nearest AED’s location and act without delay if someone collapses. Your prompt response could save their life.
FAQs
Why is defibrillation necessary?
Defibrillation is crucial in cardiac arrest emergencies. It delivers a shock that can reset the heart’s chaotic rhythm and restore normal function. Without defibrillation, survival rates drop with each passing minute. So, quick access to an AED and CPR is essential for saving lives.
What is the success rate of contesting a will?
Though this may seem unrelated to AEDs, it is. The success of contesting a will depends on the validity of claims, state laws, and the evidence. In legal disputes, consult an estate law attorney. They can assess your chances of success.
What are the differences between CPR and AED survival rates?
CPR alone provides limited blood circulation. It cannot reset an erratic heart rhythm. Combining CPR with AED defibrillation leads to a significant increase in survival rates. Survival rates for out-of-hospital cardiac arrests rise to 38% when bystanders use CPR and an AED. They are only 9% with CPR alone. This demonstrates the life-saving impact of rapid defibrillation.
What is the average success rate of an AED?
AEDs can increase survival rates to as high as 74% within three minutes of collapse. Their effectiveness depends on response time, availability, and heart rhythm during cardiac arrest. Quick action is vital to maximize the chances of survival.
Can anyone use an AED without training?
Yes, modern AEDs allow untrained bystanders to use them. These devices give clear voice instructions. They guide users to apply electrode pads and, if needed, administer a shock. Training in CPR and AED can boost confidence. It can also speed up responses in emergencies.
How do CPR and AEDs work together?
CPR provides vital blood flow to the brain and organs during cardiac arrest. An AED delivers a shock to reset the heart’s rhythm. They offer the best chance of survival. This shows the value of bystander intervention.
Conclusion
Defibrillation is vital in emergency cardiac care. AEDs are very effective at increasing survival rates in sudden cardiac arrest. Rapid action—combining CPR and AED use—can be vital. It can mean the difference between life and death. It is especially true when done within the first few minutes of a collapse. Knowing the importance of defibrillation and how AEDs work saves lives. It empowers people to act in emergencies. Quick action can save lives whether you’re a bystander or in a defibrillation program. It will also make the community safer.