Season 5 | Episode 1
Title: Heart Attack vs Cardiac Arrest
Joe McIntyre (Host): Welcome to another episode of the Merck Manuals Medical Myths podcast. On this show, we set the record straight on today’s most talked about medical topics and questions. I’m your host Joe McIntyre. And on this episode, we welcome Dr. Ranya Sweis, MD, MS and associate professor of Cardiology at Northwestern University Feinberg School of Medicine. She brings more than a decade of experience in clinical care, research and education. Today, we will explore the differences between heart attacks and cardiac arrest, causes, symptoms, and treatments for each, and how to reduce the risk of those conditions. We will also address common myths surrounding heart health and provide practical advice for maintaining a healthy heart. Dr. Sweis thanks for joining us.
Dr. Ranya N. Sweis: Thank you for having me.
Host: Let’s start off with a big one. Can you tell us what a heart attack is and what exactly causes it?
Dr. Sweis: Sure. A heart attack, or if we use medical terminology, we call it a myocardial infarction, is when something causes damage to the heart cell muscles and they start dying. This is most commonly caused by a blockage in the artery and a clot that forms at that site in arteries that supply the heart. If that area that’s supplied by the artery is no longer getting fresh blood with oxygen and nutrition, then those cells start to die. And that is, in essence, what a heart attack is.
Host: What are typically some of the most common risk factors for heart attacks?
Dr. Sweis: The most common risk factors for heart attack are a number of them, I like to think about it as a pie chart actually. Different parts of the pie chart are the things that I’m going to name off now. We think specifically of some cardiac conditions that can contribute risk for heart attack. So high cholesterol, the high cholesterol in your blood can contribute to building or the blockage getting worse and these arteries that can contribute to heart attack. High blood pressure, diabetes is a big risk factor because it impacts the blood vessels and how they heal, and also causes these blockages to build up from cholesterol that’s in the bloodstream. Patients that are smokers really set themselves up for a risk for heart attack. The other risk factors that I mentioned are lifelong and build over time. But smoking even one cigarette can cause inflammation in the blood vessels that can contribute to heart attack that time. Other risk factors definitely include obesity, lifestyle that is sedentary without exercise. One other section of the pie chart is genetics. You may not even know what your genetics are, because you are a unique combination of your two parents. So you’re not exactly the same as either parent. I have plenty of patients who, despite having parents with terrible coronary disease, don’t have heart attacks or heart disease. And the opposite. I have parents who are healthy and children who have bad coronary disease. And then the last section of the pie chart has got a question mark on it. Because as much as we know, and we know a lot about heart disease, there are still factors that we don’t completely understand.
Host: Now, I think we hear about a lot of people who are of older age who have had a heart attack, is it possible for someone who’s 40, 30, even in their 20s to have a heart attack?
Dr. Sweis: Yes, it is. And I think part of how life is in the current century contributes to that. Obesity, the high risk of diabetes, probably stress is one of the elements as well. We are seeing patients that are younger have these problems as well. But because they do take a long time to develop, it still is more common in older patients.
Host: What are some of the common symptoms of a heart attack? How do you know that what you're experiencing is a heart attack versus something that may be a little bit more benign?
Dr. Sweis: Well, if you have any concern, it's always better to get evaluated and have a professional tell you you're fine rather than think that you're fine and come in and find that something's late. I'll start with that first. That's why we're trained, let us give you the reassurance rather than try to reassure yourself and sometimes it might be too late. The most common symptoms that you'll read in a textbook are chest pain or discomfort. It's described by people sometimes as an elephant sitting on the chest. That can often be associated with a feeling of shortness of breath, so you can't get a full breath because it feels like your chest is tight. In many patients, some of this discomfort also radiates to their left arm, so they might have numbness, pain or tingling in the arm as well. Those are the most common symptoms, and we try especially to raise awareness for the fact that women's symptoms are a lot more uncommon than these textbook descriptions of chest pain and elephant sitting on the chest etc. In women, it can be just a symptom in the jaw, jaw numbness or discomfort, or just in the arm. Not the same kind of crushing chest pain. What I would recommend to people is if you've got some of the risk factors or you know that you have got a family history, if you have any of these symptoms, especially if they don't go away, please seek medical attention. And it really should be by calling 911. If the pain is gone, it might be fine to call your doctor or get an appointment. But if you have pain that won't go away say 10-15 minutes and maybe it's accelerating or it's just constant, I would call 911 to be taken to a hospital.
Host: Is there a timeframe that someone has between the origin of those symptoms and when it could be super, super serious, or does it kind of vary per person?
Dr. Sweis: It varies. If you come really quickly, you can probably really minimize the damage. I'm assuming that an artery is closed, you've got a clot completely blocking that artery and there's no flow. In the medical community, we talk about door-to-balloon time from when the patient hits the ER door to when we open the blockage with our balloons. We want that to be as low as possible. I think the official guideline is 90 minutes, but we really try to get at 60 minutes or less. That means if it happens in the middle of the night, that page is going out to everybody on the team and everybody's rushing in. Because we want to decrease the amount of time that that area of heart muscle doesn't have blood supply to decrease the amount of damage that happens overall. Of course, that is going to be impacted by did the patient sit at home for 12 hours before they came in? Or did they have symptoms for 15 minutes, they had significant concern, called an ambulance and came to the hospital right away? The amount of damage is going to be different depending on how long the patient has been having the chest pain.
Host: Now, switching gears just a little bit, what is cardiac arrest and how is that different from a heart attack?
Dr. Sweis: Cardiac arrest is a situation where the heart stops. The heart is a pump; the muscles squeeze to pump blood out to the body. A cardiac arrest is when the heart is not doing that. It can be because a heart attack is so bad, that the muscle just can't squeeze because the whole muscle is impacted. It can be because of an electrical problem. The way the heart muscle cells are coordinated to squeeze at the same time is through electricity that's passed from one cell to the next. If that electricity becomes disorganized and they have fast heart rhythms, that's kind of the situation if you think about TV shows where patients have to get shocked. Those heart rhythms can cause the heart to not beat regularly, therefore there's no blood going to the body and that's cardiac arrest as well. So, to answer your question about how they're related, a heart attack can lead to a cardiac arrest. But not all cardiac arrests are related to heart attack.
Host: Got it. What are some of the common causes of cardiac arrest? And how do they originate?
Dr. Sweis: Well, like I mentioned, a heart attack may be one of them. But probably the more common ones out in the field are arrhythmic. The arrhythmia may be due to a heart attack. The heart attack may not be a big heart attack. But when cells are dying, they become electrically disrupted and they can cause an arrhythmia to happen. That is why I actually said if you think you're having a heart attack to call 911. Because if you have an arrhythmia like this and you're in the ambulance, they'll be able to shock you out of it and completely save your life. But if you're driving your car or in a cab back of a cab, when you have that arrhythmia, you're going to stay in that arrhythmia until you get help and depending on how long that is, that may also mean brain damage from no oxygen to your brain.
Host: Are there any warning signs of cardiac arrest or because it's so severe and so quick it can be tough to recognize what is the reality there?
Dr. Sweis: It can be tough to recognize. Some patients who may have scar in their heart muscle from either a heart condition that they have, a prior heart attack, may notice that they have palpitations. If somebody notices that they get palpitations and get lightheaded or dizzy, that's something to seek attention from your primary care physician who might have you wear a monitor to try to see what these are. There are some situations where people might have some warning signs because they've got short runs of these arrhythmias before they finally become potentially fatal. But in many situations, it's hard to predict, particularly when you're talking about young athletes. Athletes are screened with an EKG to look for obvious conditions. There are some genetic conditions that can give you abnormal heart rhythms, but they may not always be present on a screening EKG. There's not really a way to screen for them or prevent them in some of the patients like we see in the news that have a cardiac arrest come out of nowhere.
Host: Now, you mentioned defibrillators a little bit. I think TV and movies maybe skew what they can actually do or what they're actually capable of. So a question for you, if someone's heart has stopped and they've been considered that they're dead or they passed away, can a defibrillator bring someone back? Yes or no? And then two, how does the defibrillator work and when would they be used?
Dr. Sweis: The defibrillator can for sure bring somebody back if it just happened. And just happened, there's kind of a little bit of a range of that. If somebody's in the throes of a cardiac arrest and we're trying to do CPR on them, we're certainly going to try to shock them. The best thing about ICDs (implantable cardioverter-defibrillators) is that they're available everywhere, and that they're almost dummy proof, too, because when you put the leads on the chest, it tells you if it's a rhythm that should be shocked or not. Some patients may arrest because they don't have electrical beats, and a shock for that isn't going to help anything. But if the patients have a disorganized fast heart rhythm that is causing their heart not to pump effectively, then a shock could potentially deliver a larger amount of electricity to almost reset the electrical system and shock it out of the abnormal heart rhythm. So that's how they work. The defibrillator that we have in all common places - schools, airports, all that - they can detect if it's an abnormal heart rhythm and recommend shock. In follow up to that, we want to get those on the chest as soon as possible. If you witness somebody's arrest, you don't want to leave that patient. You want to make sure that help is on the way. And if there's somebody around you, you want to send them to go get the defibrillator, the AED.
Host: Should someone have an AED, or the people that are in their house, if they have an older person they live with or someone who may be at risk for heart attack?
Dr. Sweis: I'm not sure the cost benefit analysis of that makes sense to put defibrillators in homes, because the vast majority of people don't have a cardiac arrest even when they do have a heart attack, right. But if patients do have a condition that is a high risk for heart attack, they will get an implanted defibrillator. Most people are more familiar with pacemakers. It kind of looks like a pacemaker, but it's a little bit bigger. Instead of just organizing the beats, it can shock a patient out of an arrhythmia. If somebody is at risk for that they will have a defibrillator. So, in effect, they have one right at home.
Host: Got it. You mentioned door-to-balloon is that the phrase you used?
Dr. Sweis: That is the phrase I used, yes.
Host: Can you talk about some of the treatments for heart attacks, and exactly how that balloon works a little bit?
Dr. Sweis: Sure. In 2023, the standard of care for somebody that has a heart attack because of an acute blockage in the artery from a clot is basically to get that clot open. A few decades ago, it would be to try to do emergency surgery to bypass that blockage. But now that we have these techniques with catheters and wires, we're able to take care of the patient much faster and save as much heart muscle as we can. What happens if somebody is having a heart attack, though, call 911. In most states, the ambulance is able to do an EKG, an electrical tracing of the heart electrical activity, and there are certain changes on that that can be definitive for heart attack. Often, if that's the case, then the ambulance might call ahead to the hospital that they're bringing the patient to and say this is an obvious heart attack. From that, the hospital will often get people started on their way, if they have that advanced knowledge and it's obvious. Basically, as soon as the patient gets to the hospital, they'll probably be hooked up to the monitor, so that it can be detected if they have any of those abnormal heart rhythms. Probably the first thing they'll also do is get aspirin. Aspirin helps to decrease the blood clotting ability and that helps to prevent further clots from developing in the artery. And then get them as fast as possible to the cardiac catheterization lab. I'm an interventional cardiologist, this is one of the things that I do. If I'm called to the cath lab for somebody having a heart attack, I know that we may be able to detect where it's coming from on the EKG but that may not be 100%. So, we're taking a couple quick pictures to see where the problem is, and quickly advance our wires and balloons into that artery to disrupt what it's doing. It's disrupting the clot and opening that blockage to allow blood flow to continue through the blood vessel.
Host: Now, we talked about some of the risk factors and I think you mentioned that it could be someone who in your family had a risk factor for heart disease or had heart attacks or not, but let's say that you have a grandparent or a parent who had a heart attack in the past, how should you go about addressing that? Should you see your doctor and mention that? Should you change any sort of lifestyle aspect? If you are predisposed, what should you do about it?
Dr. Sweis: Sure, what I should actually clarify is that it matters significantly if the person had early heart disease. That is what's really thought to be a genetic abnormality either in high cholesterol or in heart disease in particular. So, if you have a family member who had a heart attack in their 40s or 50s, you're definitely at increased risk and should have a conversation with your doctor about maximizing or minimizing all of your risks and optimizing your risk factor profile. I always say that women have it better from this perspective because they see for fertility reasons or reproductive reasons, they see a doctor on a regular basis. But in many situations, we see a man after their first heart attack, because the last time they saw a doctor was either a college or a military physical. Then they go through life, and they don't do anything about their health care until they have a heart attack. Obviously, there's still a lot we can do to help them and prevent other events but we prefer primary prevention. So, preventing the first event, not just having to do prevention for the secondary event afterwards. If there's a family history, particularly of a young family member having a heart attack and especially if they died of it, then you should in your 30s or 40s have a visit with a primary care physician to just say, “Hey, look, let's check my cholesterol, let's make sure my blood pressure is well controlled. Let me know what my risk factors are, so I know how to prevent them.” And sometimes the primary care physician might decide that it's worse and to have an appointment with a cardiologist to have that same kind of conversation, and that's completely reasonable as well.
Host: Now, I think we've all heard, or a lot of us have heard, that there are benefits to taking aspirin ahead of time or even baby aspirin. Is that actually worthwhile for someone who's at risk or has seen their doctor and may fear the potential risk of a heart attack? Is that actually the truth there?
Dr. Sweis: Well, you're referencing something that we did for many, many years. The most recent update on the guidelines for prevention has actually dropped aspirin from that preventative list. For somebody with no known heart disease, it's not found to be beneficial. However, if somebody does have a diagnosis of coronary artery disease, then that's a different story and they need to be on aspirin because that decreases the risk of them having a heart attack, knowing that they've got blockages in the arteries.
Host: When it comes to the prevention of heart disease or heart attack, what sorts of lifestyle changes should someone go about adopting? I know you mentioned obesity is one, certainly working out and exercising more. Are there any other lifestyle changes that someone should make if they are at a higher risk?
Dr. Sweis: I mentioned avoiding smoking, of course, that's probably the biggest enemy number one for our heart doctors. That's definitely a modifiable lifestyle habit. With regards to diet, I tend to err on the side of moderation because I recognize this is something that people need to do for their whole life. But the kinds of things, foods, for example, that are high calorie and fried have high saturated fats are the types of things that we should not think about as everyday types of food. These are the things that you can have on your birthday or you have a couple times a month, but not your everyday type of food. Our American, particularly, diet is really high in carbohydrates. I think that our general understanding of what is a reasonable amount is not even present. The best example that I use actually comes from an Antique Roadshow, where the antique people are often addressed by people looking at dishes, for example, and say, “These are really nice dishes. These are really nice lunch dishes, do you have the dinner plates too?” When you really think about your grandparents' dish set, for example, their dinner plates are a lot smaller than what we think of as dinner plates in our day and age now, too. That's probably one of the biggest things that we can address. When you go to an Italian restaurant, they put pasta on your plate, probably the correct serving size is half of that. So, addressing that more accurately. It's not really changing what you eat, but changing the amounts and eating a more appropriate amount for you is one way to help address keeping your weight in the more ideal range and not having obesity. But because obesity really contributes to a lot of things, people that are obese are less likely to be as active and decreases their ability to exercise as much, so that's another way that it contributes. Obesity actually also contributes to the development of diabetes. It's contributing to the development of heart disease by sort of multiple modalities. If we can think about it in terms of our lifestyle, the best thing that we can do is to be active and to moderate our diet so that we keep our body in a healthy weight range.
Host: So finally, Dr. Sweis, if our listeners have questions about heart disease, concerns about the risk factors for heart attacks or anything along those lines, where should they go for answers?
Dr. Sweis: If you have questions and want to look it up online, I would say the American Heart Association is probably the number one site that I would recommend because they have been doing this for many, many years, and at least can give people the information. So many websites can be misleading, and you don't necessarily know where they're coming from, but you can trust the American Heart Association. But of course, Merck Manuals also has some chapters on heart disease and heart attack, that's another place to get that information.
Host: Well, Dr. Sweis, thank you so much for joining us on this podcast. Certainly, a great conversation busting some of the myths on heart attacks versus cardiac arrest and talking a little bit about heart disease.
Dr. Sweis: Thanks for having me. This is definitely my passion to educate patients and help them know ahead of time what to expect, how to prevent problems and if they do have them to seek medical attention.
Host: And as we close out, I'll let Dr. Sweis leave our listeners with the final word.
Dr. Sweis: As always, medical knowledge is power and pass it on.