Automated External Defibrillator and Sudden Cardiac Arrest

What is an Automated External Defibrillator (AED)?

Automated External Defibrillators (also called Automatic External Defibrillators, AED Defibrillators, or simply AEDs), are portable electronic devices that look at a person's heart rhythm using special pads placed on the torso. AEDs can detect ventricular fibrillation (v-fib or VF) - which is a serious cardiac rhythm disturbance that causes sudden cardiac arrest - and are designed to be used by lay rescuers or first responders. AEDs can aid rescuers to determine if sudden cardiac arrest is present, and instructs them through simple, easy-to-follow steps to defibrillate the victim.

What is Sudden Cardiac Arrest (SCA)?

The native Squarespace.. Sudden cardiac arrest is the stopping of the heart at an unexpected moment. It can happen to anyone, at anytime, and at any age. This is a life threatening event but it does not have to result in sudden cardiac death (SCD). When SCA occurs, most victims have an abnormal heart rhythm called ventricular fibrillation (v-fib or VF). When the heart is in this state, it cannot beat in a normal coordinated fashion, and blood does not circulate to the heart and the brain. When SCA occurs, first, the heart stops. Then, breathing stops. The victim loses consciousness, collapses and appears lifeless. The heart must be shocked out of this state immediately for life to continue.

SCA is the most common underlying cause of death in the United States, claiming an estimated of 350,000 lives each year.[1,3]

What is the treatment for Sudden Cardiac Arrest (SCA)?

Treatment for sudden cardiac arrest is cardiopulmonary resuscitation (CPR) and an immediate shock or what is called defibrillation. With each minute that passes before the victim is shocked, the chance of survival is less. Timely defibrillation is the single most important factor in saving a SCA victim’s life. A treatment shock must be delivered within a few minutes after an SCA event to be effective; with each passing minute, the victim’s chances of survival drops ten percent.[2]

What is Sudden Cardiac Death (SCD)?

Sudden cardiac death is a sudden and unexpected death caused by loss of heart function or sudden cardiac arrest (SCA). SCD occurs primarily because lifesaving treatment, that is, CPR and defibrillation, do not reach SCA victims within the first critical minutes (unfortunately, more than half of out-of-hospital cardiac arrest goes unwitnessed).[1] CPR and defibrillation through the use of AED can dramatically increase survival rates.[4]

Who can use an Automated External Defibrillator (AED)?

Individuals who have the mental and physical capacity to learn from the AED training curriculum, and pass the AED written and skill tests can become AED-certified. Contact your local CPR/AED training center for more information about the variety of training programs and FDA-approved AED machines available in the market.

Does the AED take the place of CPR?

No. Use both AED (when available) and CPR on a sudden cardiac arrest victim.[5]

What can I do to help a sudden cardiac arrest (SCA) victim?

Become CPR/AED certified to better equip yourself to serve others during emergency situations. Nevertheless, here are some basic steps:[6]
• Evaluate victim’s symptoms and determine if sudden cardiac arrest is present. If present,
• Get or yell for help; call or ask someone to call 9-1-1 or the local emergency telephone number
• Get or ask someone to obtain an AED (if AED is available)
• Begin CPR if victim is barely or not breathing
• Use AED as soon as it is available
• Continue until victim starts moving and/or breathing, or until first responders arrive at the scene and takes over

Can AED be used to treat infants and children?

• 0 to 1 Years - No Defibrillation recommended.
• 1 to 8 Years - Yes with pediatric AED pads for individuals weighing up to 55 pounds.
• 8 Years and older - Yes with the standard AED adult pads for individuals weighing above 55 pounds.[7]

Can I hurt someone with an AED?

Very little to no chance. AEDs are designed to not shock someone who does not need to be shocked.[7]

What about using an AED on metal or wet surfaces?

Always check with the manufacturer. Most AEDs can be safely used in wet environments and on metal surfaces with no risk to the victim or rescuer because they are self-grounded devices. If the sudden cardiac arrest victim’s bare chest is wet, wipe dry before attaching AED pads.[8]

Hypertrophic Cardiomyopathy


What is Hypertrophic cardiomyopathy (HCM)?

Hypertrophic cardiomyopathy (HCM) is a hereditary disease characterized by an abnormal enlargement or thickness of muscle in the heart, which can sometimes obstruct blood flow.[2,9,12,21]

Alternate names for Hypertrophic cardiomyopathy (HCM) include:[10,11]
• Asymmetric septal hypertrophy
• Familial hypertrophic cardiomyopathy
• Hypertrophic nonobstructive cardiomyopathy
• Hypertrophic obstructive cardiomyopathy
• Idiopathic hypertrophic subaortic stenosis (IHSS)

How common is Hypertrophic cardiomyopathy (HCM)?

HCM is a common inherited heart disease that affects 1 in 500 individuals worldwide. In the United States, an estimated number of 500,000 individuals live with HCM, including those who may or may not be aware about having the disease.[1] Due to scientific advances and more accurate diagnosis of the disease, HCM mortality rate has dipped below one percent in recent years.[1,15,21]

What are the symptoms of Hypertrophic cardiomyopathy (HCM)?

Most individuals living with HCM have very few to no symptoms and lead normal lives. Although HCM affects individuals of all ages, symptoms of the disease are more severe among adolescence. Sudden cardiac arrest and death are rare but fatal results of HCM, more prevalent among competitive young athletes and individuals age 12 to 25.[1,17] Common symptoms of include:[9,10,12,13]
• Shortness of breath or trouble breathing (especially during or right after physical exertion)
• Abnormal blood pressure (especially during or right after physical exertion)
• Chest pain (especially during physical exertion or after heavy meals)
• Palpitations or irregular heartbeats
• Light-headedness
• Dizziness
• Swelling in the ankles, feet, legs, abdomen, and veins in the neck
• Loss of consciousness

What are the risk factors of Hypertrophic cardiomyopathy (HCM)?

Some risk factors include individuals with:[1,9,14,16]
• Close relative (parents, children, sibling) with the HCM
• History of sudden cardiac arrest
• Extreme thickness of left ventricular wall (30 mm or more) on echocardiogram
• Common and rare HCM symptoms mentioned herein
• History of arrhythmias (improper beating of the heart, whether irregular, too fast, or too slow)

Who should be screened for Hypertrophic cardiomyopathy (HCM) ?

• Individuals, regardless of age, who display symptoms and risk factors mentioned herein should be screened regularly.
• Most doctors and experts, including the American Heart Association/American Stroke Association, recommend that all individuals ages 12 to 25 be screened regularly.[17,18]

How is Hypertrophic cardiomyopathy (HCM) screened?

All individuals ages 12 to 25 will be routinely screened using the 14-Element Screening (also known as the 14-Element Checklist). If results from routine screening warrant further evaluation, the Twelve-lead electrocardiography (ECG), echocardiogram, cardiac catheterization or radionuclide angiograph can be used.[18,19,20,21]

Due similar symptoms, HCM can be misdiagnosed as:[21]
• Asthma or exercise-induced asthma
• Mitral valve prolapse
• Anxiety attacks/panic attacks
• Some forms of depression

How is Hypertrophic cardiomyopathy (HCM) treated?

There is no cure, however, HCM is treatable and symptoms are manageable if diagnosed correctly.

Treatments may include (but are not limited to):[15,22]
• Medications — Certain medications may help reduce the thickness of the enlarged muscle. Beta blockers and calcium channel blockers can relieve chest pains, palpitations and shortness of breath; both are anti-arrhythmic medications.
• Surgery — For severe cases of HCM or those that don't respond to medication treatment, surgery (such as septal myectomy) may be an option.
• Implantable cardioverter-defibrillator (ICD) — Devices that emit electrical impulses telling the heart when to beat. If an arrhythmia occurs, the device shocks and restores the heart to normal rhythm. In recent years, ICDs have become more compact and less obtrusive to implant.

Abbreviations Used    

  • AED - automated external defibrillators or automatic external defibrillators    

  • CPR - cardiopulmonary resuscitation    

  • ECG - electrocardiography    

  • FDA - Food and Drug Administration (which is an agency within the U.S. Department of Health and Human Services)    

  • HCM - Hypertrophic cardiomyopathy    

  • ICD - Implantable cardioverter defibrillators    

  • IHSS - Idiopathic hypertrophic sub-aortic stenosis    

  • SCA - sudden cardiac arrest    

  • SCD - sudden cardiac death    

  • V-fib or VF - ventricular fibrillation


[1] Dariush Mozaffarian, MD, DrPH, FAHA; Emelia J. Benjamin, MD, ScM, FAHA; Alan S. Go, MD; Donna K. Arnett, PhD, MSPH, FAHA; Michael J. Blaha, MD, MPH; Mary Cushman, MD, MSc, FAHA; Sandeep R. Das, MD, MPH; Sarah de Ferranti, MD, MPH; Jean-Pierre Després, PhD, FAHA; Heather J. Fullerton, MD, MAS; Virginia J. Howard, PhD, FAHA; Mark D. Huffman, MD, MPH, FAHA; Carmen R. Isasi, MD, PhD; Monik C. Jiménez, ScD; Suzanne E. Judd, PhD; Brett M. Kissela, MD, MS, FAHA; Judith H. Lichtman, PhD, MPH; Lynda D. Lisabeth, PhD, MPH, FAHA; Simin Liu, MD, ScD, FAHA; Rachel H. Mackey, PhD, MPH, FAHA; David J. Magid, MD, MPH; Darren K. McGuire, MD, MHSc, FAHA; Emile R. Mohler III, MD, FAHA; Claudia S. Moy, PhD, MPH; Paul Muntner, PhD; Michael E. Mussolino, PhD, FAHA; Khurram Nasir, MD, MPH; Robert W. Neumar, MD, PhD; Graham Nichol, MD, MPH, FAHA; Latha Palaniappan, MD, MS, FAHA; Dilip K. Pandey, MD, PhD, FAHA; Mathew J. Reeves, PhD, FAHA; Carlos J. Rodriguez, MD, MPH, FAHA; Wayne Rosamond, PhD, FAHA; Paul D. Sorlie, PhD; Joel Stein, MD; Amytis Towfighi, MD; Tanya N. Turan, MD, MSCR, FAHA; Salim S. Virani, MD, PhD; Daniel Woo, MD, MS, FAHA; Robert W. Yeh, MD, MSc, FAHA; Melanie B. Turner, MPH; on behalf of the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics --- 2016 update: a report from the American Heart Association. CIR.0000000000000350 Published online before print December 16, 2015, doi: 10.1161/CIR.0000000000000350. Accessed January 19, 2016.

[2] Sudden Cardiac Arrest Treatment. Sudden Cardiac Arrest Foundation. Accessed January 19, 2016.

[3] Cedars-Sinai physician developing risk assessment for sudden cardiac arrest. AAAS and EurekAlert!. Published online January 11, 2016. Accessed January 19, 2016.

[4] Jocelyn Berdowski, PhD; Marieke T. Blom, MA; Abdennasser Bardai, MD; Hanno L. Tan, MD, PhD; Jan G.P. Tijssen, PhD; Rudolph W. Koster, MD, PhD. Impact of Onsite or Dispatched Automated External Defibrillator Use on Survival After Out-of-Hospital Cardiac Arrest. American Heart Association. Circulation. 2011; 124: 2225-2232, Published online before print October 17, 2011, doi: 10.1161/CIRCULATIONAHA.110.015545. Accessed January 19, 2016.

[5] AED Implementation. American Heart Association. Accessed January 19, 2016.

[6] Warning Signs and Emergency Treatment of Cardiac Arrest. American Heart Association. Updated September 10, 2014. Accessed January 19, 2016.

[7] FAQs. Accessed January 19, 2016.

[8] Be Redcross Ready. American Red Cross. Accessed January 19, 2016.

[9] Mayo Clinic Staff. Hypertrophic cardiomyopathy: Overview. Published online February 18, 2015. Accessed January 19, 2016.

[10] Hypertrophic cardiomyopathy. American Heart Association. Accessed January 19, 2016.

[11] Hypertrophic cardiomyopathy. University of Maryland Medical Center. Last reviewed May 13, 2014. Accessed January 19, 2016.

[12] Health Guide: Hypertrophic cardiomyopathy. New York Times. Review Date June 4, 2012. Accessed January 19, 2016.

[13] What Are the Signs and Symptoms of cardiomyopathy? National Heart, Lung, and Blood Institute. Accessed January 19, 2016.

[14] Barry J. Maron, MD. Cardiology Patient Page: Hypertrophic cardiomyopathy. American Heart Association. Circulation. 2002; 106: 2419-2421 doi: 10.1161/01.CIR 0000034170.83171.0B. Accessed January 19, 2016.

[15] Barry J. Maron, MD; Steve R. Ommen, MD; Christopher Semsarian, MBBS, PhD; Paolo Spirito, MD; Iacopo Olivotto, MD; Martin S. Maron, MD. Hypertrophic Cardiomyopathy Present and Future, With Translation Into Contemporary Cardiovascular Medicine. The Journal of the American College of Cardiology. Published online July 1, 2014. J Am Coll Cardiol. 2014;64(1):83-99. doi:10.1016/j.jacc.2014.05.003. Accessed January 19, 2016.

[16] About Arrhythmia. American Heart Association. Last reviewed October 23, 2014. Accessed January 19, 2016.

[17] Congenital and genetic heart disease screening recommendations for people 12-25: American Heart Association/American College of Cardiology Scientific Statement. American Heart Association/American Stroke Association. Published online September 15, 2014. Accessed January 19, 2016.

[18] How to screen for HCM: Screenings for those with a family member with HCM. Hypertrophic Cardiomyopathy Association. Accessed January 19, 2016.

[19] The Pediatric Primary Care Clinic (Gardner-Packard Children's Health Center). Published online 2014. Circulation Barry J. Maron, MD. Accessed January 19, 2016.

[20] Barry J. Maron, MD, FACC; Richard A. Friedman, MD, FACC; Paul Kligfield, MD, FAHA; Benjamin D. Levine, MD; Sami Viskin, MD; Bernard R. Chaitman, MD, FAHA; Peter M. Okin, MD, FAHA, FACC; J. Philip Saul, MD, FAHA, FACC; Lisa Salberg; George F. Van Hare, MD; Elsayed Z. Soliman, MD, FAHA, FACC; Jersey Chen, MD, MPH; G. Paul Matherne, MD, FAHA, FACC; Steven F. Bolling, MD, FAHA; Matthew J. Mitten, JD; Arthur Caplan, PhD; Gary J. Balady, MD, FAHA; Paul D. Thompson, MD, FAHA, FACC. Assessment of the 12-Lead Electrocardiogram as a Screening Test for Detection of Cardiovascular Disease in Healthy General Populations of Young People (12–25 Years of Age). Published online October 2014. Accessed January 19, 2016.

[21] Hiroo Takayama, MD. Hypertrophic Cardiomyopathy and Heart Failure. The Department of Surgery at NewYork-Presbyterian/Columbia University Medical Center. Accessed January 19, 2016.

[22] HCM Treatment Options. Hypertrophic Cardiomyopathy Association. Accessed January 19, 2016.

[23] Image source of Hypertrophic cardiomyopathy illustration is Adam, Inc. ( Accessed January 19, 2016.

 The purpose of this FAQ page is to provide awareness and general information about the topics mentioned herein. The Derrick Faison Foundation is not in the practice of providing medical advice. To get professional medical advice about the topics mentioned herein, contact your medical service provider. If you are having a medical emergency, please call 9-1-1 or the emergency telephone number in your area. List of references and mentions of organizations do not equal endorsements.

Last reviewed January 19, 2016