Cardiac Arrest and “Sudden Cardiac Death”: An Overview
Guest: Dr. Michael Gold - Cardiology
Host: Dr. Bill Spencer – Cardiology
Dr. Bill Spencer: I am Dr. Bill Spencer and with me is Dr. Michael Gold who is the professor of Medicine and chief of Cardiology division at the Medical University of South Carolina. Michael is going to speak with us today about an area in which he has a great deal of experience, sudden cardiac death. Michael, I think the best thing to begin with is for you to define sudden cardiac death for me, please.
Dr. Michael Gold: Well, this is a term that we use medically for people who have a cardiac arrest. So, when we hear about people who die suddenly in their sleep, pass away in their sleep, or collapse on the street or somewhere else and go directly into a cardiac arrest, when the ambulance gets called, that is called sudden cardiac death.
Dr. Bill Spencer: So, when somebody dies suddenly, it is always said to be due to the heart, is that true?
Dr. Michael Gold: Most of the time. About 80 to 90 percent of the time, it is due to the heart. Contrary to popular opinion, or beliefs, it is not due to the heart beating too slow or the heart stopping, it is actually due to the heart beating too fast and going into what is called fibrillation.
Dr. Bill Spencer: How common is sudden cardiac death?
Dr. Michael Gold: It is very common. It is actually probably the leading cause of death in the United States. One person a minute has a cardiac arrest in the United States.
Dr. Bill Spencer: How big of an economic problem is this?
Dr. Michael Gold: It is a very large economic problem, where we spend several billions of dollars every month just in treating patients and in lost revenue and wages from people, not to mention that, obviously, tragically, people die every day and virtually every minute from this problem.
Dr. Bill Spencer: Okay, so you say that sudden cardiac death almost always comes from the heart, but what are the causes of sudden cardiac death?
Dr. Michael Gold: Typically we see this in people who have heart damage. The most common cause of heart damage is a previous heart attack. Commonly, people, again, would say that someone has a heart attack when they have a cardiac arrest. But, it is usually not a heart attack at the time, but it is an old or previous heart attack that they had. There are other causes of heart damage that could be due to viruses. It could be due to high blood pressure. It could be due to leaky valves. They can all lead to the problem of sudden death.
Dr. Bill Spencer: Tell us what a heart attack is.
Dr. Michael Gold: A heart attack is when we have a blockage in one of the arteries that supplies the heart so that we are not getting blood going to that heart muscle, and that causes that part of the heart muscle, that is supplied by blood from that blockage, to die and be injured.
Dr. Bill Spencer: It produces a scar?
Dr. Michael Gold: It produces a scar and permanent damage to that heart muscle and that can lead to the dangerous heart abnormalities of sudden death.
Dr. Bill Spencer: Do we have any ways of diagnosing, beforehand, or diagnosing the predisposition or tendency to have sudden cardiac death?
Dr. Michael Gold: Yes. Fortunately, we have found that there are some very simple ways of identifying high-risk patients. First, if they have had a history of any heart damage or any heart disease. The second is we actually measure the heart function with an ultrasound or echo machine and we calculate the percentage of the heart function. When that percentage gets below about 35 percent, it identifies a very high-risk patient. The third factor is heart failure which is the inability of a patient to do their normal activities because of either having fluid problems or because they are short of breath. Those are the three main factors that we use to identify high-risk groups of patients for sudden death.
Dr. Bill Spencer: So, if you identify somebody of being high-risk for sudden death, what can you do about it?
Dr. Michael Gold: Well, typically there is a group of medicines that we know are very good for the heart, to protect it, medicines such as aspirin to prevent heart attacks, statins, or medicines to control hypercholesterolemia, medicines such as beta blockers. So, we have a whole group of medicines. But, in a very high-risk group of patients, we put in what is called a defibrillator, or an ICD, which is a small device that goes under the skin, which simply waits for a sudden death event to occur and then either paces or shocks the heart automatically to get the heart rhythm back to normal.
Dr. Bill Spencer: Well, that is excellent. How reliable are these defibrillators now?
Dr. Michael Gold: Well, someone who has a cardiac arrest outside the hospital has about a one in one hundred chance of surviving. If you have a defibrillator in place, you have about 99 out of 100 chance of surviving. So, they are extremely effective for this therapy.
Dr. Bill Spencer: How about these automated external defibrillators (AEDs) we see in airports now?
Dr. Michael Gold: AEDs are very good so that if someone has a cardiac arrest, we can resuscitate them. For the highest risk patients, we would rather have an implantable device. But, certainly, in public places such as shopping centers, airports, even some school yards where we occasionally see athletes who may be at risk for other reasons for sudden death, AEDs are very useful and it is very good to be trained and learn how to use them.
Dr. Bill Spencer: Does it take a lot of training to learn how to use them?
Dr. Michael Gold: No. They are very simple. It just takes a couple of minutes. Most of them are designed to be automatically user-friendly by communicating. They actually talk to people so they can help you work through using them if you are in a situation where someone has collapsed on a street or on the floor.
Dr. Bill Spencer: So, we have talked about sudden cardiac death and what it is and how you take care of it. Do you see any changes in the number of sudden cardiac deaths that are occurring annually?
Dr. Michael Gold: Unfortunately, we are seeing that this number is not going down. While we have made great strides in preventing heart attacks and preventing a lot of other diseases, we are still seeing very frequent episodes of sudden death. So, it remains a major healthcare problem that we need to pay more and more attention to.
Dr. Bill Spencer: Well, I think we are fortunate to have people like you working on it. Thank you very much.
Dr. Michael Gold: Thank you.
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