What does defibrillation do to the heart

The AED can recognize a rapid or irregular heart rhythm that requires a shock. And, it can advise the rescuer when a shock is needed. The AED uses voice prompts, lights, and text messages to tell the rescuer the steps to take. AEDs are very accurate and easy to use. There are many different brands of AEDs, but the same basic steps apply to all of them. The American Heart Association doesn't recommend a specific model.

Most anyone with or without a medical background can learn to use an AED or apply the pads properly and administer a shock by following the prompts provided by the AED. The computerized device will tell a rescuer to push the defibrillate button if cardiac arrest is from an abnormal heart rhythm that could respond to a shock. Not all rhythms will. This could be either ventricular fibrillation or ventricular tachycardia.

Ventricular fibrillation is the most common heart-rhythm problem in victims of sudden cardiac arrest. The cost of AEDs has decreased a lot in the past few years.

Electrical impulses contract the muscles surrounding the heart in order to provide oxygenated blood to the body. The rhythm of the heart is controlled by a natural pacemaker referred to as the sinus node, located in the right atrium, one of the upper chambers of the heart.

During sudden cardiac arrest, the heart stops beating normally. The AED can eliminate the abnormal heart rhythm by depolarizing the entire electrical system of the heart. This allows the heart to fully repolarize and recommence normal electrical function. The shock needs to be of sufficient power to completely repolarize the cells, otherwise an irregular rhythm may continue. When the heart muscles repolarize, the sodium channels in the muscle cells close, the potassium ion channels open, and the muscle cells rest.

Depolarization opens the sodium channels which stimulates the heart muscles to contract. This provides the rhythm, or wave form, that can be read and interpreted by the AED to determine if a shock is needed or not. When an AED is analyzing the rhythm, it is the electrical impulse that is measured, not the actual physical movement of the heart. There are several types of heart rhythms that can be corrected by a defibrillator. Defibrillation is a medical technique used to counter the onset of ventricular fibrillation, VF a common cause of cardiac arrest, and pulseless ventricular tachycardia, which sometimes precedes ventricular fibrillation but can be just as dangerous on its own.

Defibrillation is a technique used in emergency medicine to terminate ventricular fibrillation or pulseless ventricular tachycardia. It uses an electrical shock to reset the electrical state of the heart so that it may beat to a rhythm controlled by its own natural pacemaker cells. It is not effective for asystole complete cessation of cardiac activity, more commonly known as "flatline" and pulseless electrical activity PEA.

The purpose of defibrillation of ventricular arrhythmias is to apply a controlled electrical shock to the heart, which leads to depolarization of the entire electrical conduction system of the heart.

When the heart repolarizes, the normal electrical conduction may assert itself, in which case the ventricular arrhythmia is terminated. Replacing the battery is less involved than the original surgery to implant the ICD. Ask your doctor whether the device generator or its wires need to be replaced, too. Manage devices that can interfere with your ICD. To be safe, keep your ICD at least six inches away from the following devices, or, when necessary, use them only briefly: Cell phones.

If you have an ICD on the left side of your chest, hold your cell phone to your right ear. Most headphones have a magnetic element in them. Wear them as far away from your ICD as possible, and do not carry your headphones in a chest pocket.

Metal detectors, such as those used for airport security. The risk of harm is low, but you can show your ID card and ask for alternative inspection. Learn the warning signs of complications and make a plan. Call your doctor if you have signs of symptoms that concern you, and if you have these signs in particular: Fainting Dizziness or feeling out of breath Fever Heart palpitations or chest pain Go to a hospital emergency room if you feel many strong shocks from your device in a short time.

Tend to your emotional health. Return to Who Needs Them? Research for Your Health. Improving health with current research. Advancing training in emergency care. This program will support young investigators who are committed to research careers in emergency cardiovascular medicine.

Funding advances in emergency response. The Resuscitation Outcomes Consortium ROC is a clinical trial network that tests treatments to address high rates of injury and death from out-of-hospital cardiac arrest and severe traumatic injury. Researchers are comparing how emergency response teams transport patients to the hospital to look for ways to improve outcomes.

A registry of sudden cardiac arrests that ROC established has helped track important information about these events. In , ROC data helped show that more patients survive sudden cardiac arrest in public spaces when bystanders use an AED while waiting for a standard emergency response.

In addition, patient outcomes were better when bystanders used an AED. Promoting a clinical trial network to address emergency medicine. Helping show how AEDs can save lives.

Our Public Access Defibrillation trial helped show the value of having AEDs in public spaces by showing they could increase survival among people experiencing sudden cardiac arrest. Researchers found that more people experiencing sudden cardiac arrest survived when teams of volunteers trained in CPR and AED use responded, compared with volunteer responders trained in CPR only. We funded research that showed that for patients with mild or moderate congestive heart failure and a weakly pumping heart, conventional heart failure treatment paired with a simple ICD therapy is more effective than the conventional treatment alone.

Survival rates were 23 percent higher among patients with an ICD. Supporting heart failure research collaboration. The HFN brings together nine Regional Coordinating Centers and additional clinical sites in the United States to form a collaborative platform to research strategies that address the increasing public health burden of heart failure.

Assessing optimal use of AEDs. Advancing research for improved health. We perform research. Specific projects aim to answer clinically relevant questions in diagnostics, therapeutics, and interventions. We fund research. The Heart Failure and Arrhythmia Branch within the DCVS supports research to advance our understanding of and interventions for pediatric and adult cardiovascular diseases.

We also support the development of innovative technologies to diagnose, prevent, and treat heart and vascular diseases. The Center for Translation Research and Implementation Science supports research to translate these discoveries into clinical practice.

We stimulate high-impact research. Findings from TOPMed may help us understand how genes contribute to the development of atrial fibrillation—for example, in women and in patients who have no underlying heart disease.

Read more. Using genetic information to assess risk of complications. Some genetic conditions can be treated with an ICD to monitor and correct abnormal heart rhythms. However, even people with the same genetic pattern do not all have the same risk of developing a life-threatening arrhythmia. Improving ICD design. Although high-energy shocks are effective therapy for arrhythmias, they can startle patients and cause them distress or pain. Read less.

Are you considering getting or replacing an implantable cardioverter defibrillator? Implantable cardioverter defibrillators ICDs can present patients with many stressful decisions, and this study tests the effectiveness of educational videos and handouts to inform patients about ICDs and help them assess their options. To participate in this study, your doctor must have given you the option of implanting or replacing an ICD. The study is located in Denver, Colorado. This study will investigate health outcomes among people with a heart conduction disorder that is sometimes treated with an implantable cardioverter defibrillator.

To participate in this study, you must be between 18 and 60 years old and have complete left bundle branch block. The study takes place in Beijing, China. This study aims to learn what signs distinguish patients who have a higher risk of an arrhythmia that leads to sudden cardiac arrest.

Researchers plan to track patients with a recent ICD replacement for 10 years. To participate in this study, you must be between 18 and 85 years old. This study is located in Washington, D. This study tests the safety and effectiveness of a new tool for doing radiofrequency catheter ablations, a treatment for some conduction disorders. To participate in this study, you must be at least 18 years old and have ventricular tachycardia that has not gone away after treatment with medicine, ablation, and placement of an implantable cardioverter defibrillator ICD.

This study is located in Illinois and Minnesota. This study aims to evaluate the safety and effectiveness of low-energy shocks for the treatment of ventricular tachycardia and ventricular fibrillation. This approach will be tested during a catheter ablation or placement of an implantable cardioverter defibrillator ICD.

To participate in this study, you must be between 18 and 75 years old. This study is located in Minneapolis, Minnesota, and Austin, Texas. More Information.

Related Health Topics Arrhythmia. Atrial Fibrillation. Congenital Heart Defects. How the Heart Works. Long QT Syndrome. Sudden Cardiac Arrest. NHLBI resources. November 13,