Skip to main content Skip to home page

Your Health Blog

    Understanding Sudden Cardiac Arrest

    Chandrashekar Kumbar, MD, FACC MD, FACC, Deaconess Heart Group 10/09/2019

    In my 17 years here at Deaconess Heart Group, I’ve cared for many patients who have experienced sudden cardiac arrest; I’ve also heard many stories of those who did not survive sudden cardiac arrest. October is Sudden Cardiac Awareness Month, and so The Heart Hospital and the Deaconess Foundation are working to raise awareness of sudden cardiac arrest, and also are working to place AEDs throughout our communities.
    What is cardiac arrest?
    Cardiac arrest is the abrupt loss of heart function in a person who may or may not have diagnosed heart disease—meaning, it often happens to people who most would think are at low risk or are otherwise healthy. The time and mode of death are unexpected. It occurs instantly or shortly after symptoms appear.

    • Each year, more than 420,000 cardiac arrests occur in the United States (outside the hospital).
    • Each year, nearly 350,000 people die of sudden cardiac arrest. This number is more than deaths related to breast cancer, stroke and lung cancer combined.
    • Many people think that heart attack and sudden cardiac arrest are the same thing, but they’re not.
    • What is a heart attack?

    The term "heart attack" is often mistakenly used to describe cardiac arrest. And while a heart attack can cause cardiac arrest and sudden death, the terms don't mean the same thing. One is related to the “electrical” system of the heart, and the other is related to the “plumbing” of the heart.
    Heart attacks are caused by a blockage that stops blood flow to the heart. A heart attack (or myocardial infarction) refers to death of heart muscle tissue due to the loss of blood supply, not necessarily resulting in the death of the heart attack victim.
    Cardiac arrest is caused when the heart's electrical system malfunctions. In cardiac arrest death results when the heart suddenly stops working properly. This may be caused by abnormal, or irregular, heart rhythms (called arrhythmias).

    A common arrhythmia in cardiac arrest is ventricular fibrillation. This is when the heart's lower chambers suddenly start beating chaotically and don't pump blood. Death occurs within minutes after the heart stops. Cardiac arrest may be reversed if CPR is performed and a defibrillator is used to shock the heart and restore a normal heart rhythm within a few minutes.
    Understanding your risk for cardiac arrest
    Cardiac arrest may be caused by almost any known heart condition. Most cardiac arrests occur when the heart's electrical system malfunctions, producing an abnormal rhythm. Some cardiac arrests are caused by extreme slowing of the heart's rhythm.

    Those who are at higher risk include people with the following conditions:

    • Patients with congestive heart failure are at high risk for sudden cardiac arrest. The heart is already weakened and not functioning well.
    • Scarring from a prior heart attack or other causes. A heart that's scarred or enlarged from any cause is prone to develop life-threatening ventricular arrhythmias.
    • A thickened heart muscle (hypertrophic cardiomyopathy) is a common cause of sudden death, especially among athletes.
    • Heart medications: Under certain conditions, various heart medications can set the stage for arrhythmias that cause sudden cardiac arrest.
    • Electrical abnormalities: Certain electrical abnormalities may cause sudden cardiac arrest in children and young people.
    • Blood vessel abnormalities: Less often, blood vessel abnormalities (present from birth), particularly in the coronary arteries and aorta, may be present in young sudden death victims. Adrenaline released during intense physical or athletic activity often acts as a trigger for sudden cardiac arrest when these abnormalities are present.
    • Recreational drug use: In people without other heart disease, use of street drugs or abuse of prescription drugs is a cause of sudden cardiac arrest.

    Can children experience sudden cardiac arrest?
    Sadly, sudden cardiac arrest does happen in children. In infants and children, most cardiac arrests result from progressive respiratory failure, shock, or both. Less commonly, pediatric cardiac arrests can occur without warning (i.e. with sudden collapse) secondary to an arrhythmia.
    How important is CPR and/or AEDs?
    When cardiac arrest occurs, the lower chamber of the heart is fibrillating. That means it is not pumping. This results in an abrupt drop in blood pressure and sudden loss of consciousness.
    The brain can survive up to 15 minutes without adequate oxygen. To minimize the brain damage, CPR should be initiated immediately. CPR provides adequate circulation through the body to deliver oxygenated blood, helping the patient survive.
    AEDs—automatic external defibrillators—are designed to be used by anyone (no special training needed), and they deliver an electric shock to the heart, often restoring normal rhythm. The AEDs analyze any existing rhythm that exists in the heart, and will shock appropriately. It’s important to note that the AED will NOT shock unless it’s warranted, so you can’t hurt someone with it.
    Ways to reduce risk of sudden death
    If someone is at higher risk for sudden cardiac arrest, they are often a good candidate for an ICD—an implantable cardioverter defibrillator. Many people simply call them a defibrillator.
    ICDs are electronic devices implanted in patients who are high risk for sudden death, like those with known congestive heart failure, post heart attack, or patients with reduced heart function.

    ICDs are implanted via a minor surgical procedure, and they stay in the body for up to 10 years.  Their job is to sense any irregularities in the heart’s rhythm and automatically shock the heart into a better rhythm.
    People with ICDs may go months or years without the ICD ever shocking them. But when it does happen, they know.
    In large clinical trials, among patients who were receiving good medical treatment, ICDs lead to the best outcomes and highest survival rates. Also, certain medications can be used to address the frequency of irregular heart rhythm, even among those patients with ICDs. They help to reduce the frequency of the ICD needing to shock. Other medications that treat heart conditions can improve -heart function, leading to a lower risk of sudden cardiac arrest.
    Patients with a history of loss (or near loss) of consciousness, especially among those with a history of heart conditions, should talk with their cardiologist about an ICD. All patients with congestive heart failure, especially those with ejection fraction of less than 35% (low heart function) should be screened for sudden cardiac arrest risk.
    Patients with multiple family members who have died suddenly at a relatively young age or under suspicious unexplained circumstances should be screened for sudden cardiac arrest risk factors.

    What are other factors that affect risk of sudden cardiac arrest?

    • Smoking. I can’t say enough how important it is for one’s health to either stop smoking or just never start.
    • Weight/obesity management. Those who are overweight are at higher risk of all cardiac events.
    • Excess alcohol use can affect the heart’s rhythm and function.
    • Uncontrolled high blood pressure damages the heart in many ways.
    • Sleep apnea is a risk factor for cardiac arrest. This is a condition related to a person who stops breathing repeatedly as they sleep. You can learn more about it at

    What is HeartSaver?
    The Heart Hospital at Deaconess Gateway and the Deaconess Foundation created HeartSaver with the mission to reduce sudden death through placement of life-saving automated external defibrillators (AEDs) in the Tri-State.

    AEDs are proven to save lives. As I’ve explained, they work to restore heart rhythm in a heart that is either stopped, or not beating properly. Below are some examples of how AEDs have saved lives:

    • This year, in a Tri-State area Schnucks, a customer experienced a sudden cardiac event. Fortunately, each Schnucks has an AED on site. A store manager successfully used that device to save the customer's life.
    • A healthy 35 year old physician collapsed in his office experiencing a sudden cardiac emergency. He had no pulse and stopped breathing. Fortunately a cardiologist's office was across the hall and he came running with an AED. The cardiologist used it to shock the heart back to rhythm so the physician could be transported to the Heart Hospital. He is healthy and very much alive today.
    • A second-year dental student at IU School of Dentistry had no recollection of suffering cardiac arrest and collapsing to the floor in the lab. He is thankful the students and staff were present, started CPR and applied an AED to save his life.

    How does HeartSaver work?
    HeartSaver works to raise funds and place AEDs in local contacts, churches, schools and other community locations where many people gather. HeartSaver facilitates the fund raising, purchase, education and placement, and includes training at the time of placing the AED.

    How can I donate to HeartSaver?
    Donations may be made in any amount, and checks may be written to Deaconess Foundation with The Heart Hospital HeartSaver in the designation line. Donors at the level of $1000 may select where they'd like an AED placed. All donations are tax deductible.

    Learn more information about our HeartSaver program or contact Penny Goshert 812-842-3472.
    Some information/statistics are from the American Heart Association,


Top Back to top