What Happens During a Heart Attack?
Heart attacks are, unfortunately, quite common in the United States. In fact, a heart attack happens every 40 seconds here. Dr. John Mounsey explores what exactly happens in your body when you're having a heart attack.
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Learn more about John Mounsey, BM, BCh, PhD, FRCP, FACC
John Mounsey, BM, BCh, PhD, FRCP, FACC
J. Paul Mounsey, M.D., Ph.D., FACC, a nationally recognized leader in electrophysiology, will join UAMS on Oct. 1 as director of the Division of Cardiovascular Medicine in the UAMS College of Medicine Department of Internal Medicine and director of the cardiovascular program at UAMS.Learn more about John Mounsey, BM, BCh, PhD, FRCP, FACC
Transcription:
What Happens During a Heart Attack?
Caitlin Whyte: Heart attacks are unfortunately quite common in the United States. In fact, one happens every 40 seconds here. But what exactly is happening in your body during a heart attack? To tell us more, we are joined by Dr. John Mounsey, the Director of Cardiovascular Service Line, a Professor of Medicine and the Chief of the Division of Cardiology.
This is UAMS Health Talk, the podcast by the University of Arkansas for Medical Sciences. I'm Caitlin Whyte. Now, doctor, let's start with that big question in our intro. What is happening in our bodies during a heart attack?
John Mounsey, BM, BCh, PhD, FRCP, FACC: Okay. So a heart attack occurs when an area of the heart is deprived of its blood supply. If you think about the heart, it's a muscular pump. Actually, it's several muscles and valves and things all loosely joined together, but it's a muscular pump and muscles require energy. They get energy from oxygen and sugar and things in the blood. So the first thing the body does is it pumps blood out to the heart around the body as it looks after the pump. And the two first arteries that come off the aorta, that's the main artery on the top of the heart, are called the coronary arteries because they supply the heart. And the coronary arteries grasp the heart a bit like fingers grasping a baseball and each coronary artery looks after a different bit of heart.
And if there is buildup of plaque or fatty deposits in the walls of the arteries, then they can become blocked. If they'd become partially blocked, you could develop chest pain and we call that angina. If they become completely blocked, then you develop a heart attack and the little bit of heart looked after by that artery dies.
Caitlin Whyte: So what causes a heart attack or causes that buildup?
John Mounsey, BM, BCh, PhD, FRCP, FACC: The buildup of blockages in the arteries around the heart is caused by buildup of cholesterol in the walls of the arteries. In fact, in Western populations, we've known for a long time now that the very first signs of developing cholesterol in the walls of the coronary artery start very young in life and they progress. In people who are prone to developing blocked coronary arteries, they progress through life. And plaques, just minor rufflings in the wall of the artery, can over a period of years develop into blockages.
The actual initiating event of a heart attack or the thing that makes a heart attack such a catastrophic and sudden event is that if you could imagine you've got plaques, which are like narrowings in the walls of the arteries. And if one of those ruptures, then you can go from a narrow artery to a completely blocked artery in a matter of a few seconds. Because if a plaque ruptures, cholesterol leaks out of the block and the body will try and wall that off and form a blood clot or what we call a thrombus inside the coronary artery, and that causes catastrophic and complete blockage of the coronary artery. That's why a heart attack is sometimes called a coronary. You may have heard it called a coronary thrombosis. It means a blood clot in the coronary artery caused by the rupture of a plaque. And it's that catastrophic loss of blood flow to a section of the heart that leads to a heart attack.
Caitlin Whyte: So then what are some symptoms that we can look out for that might signal a heart attack is happening or about to happen?
John Mounsey, BM, BCh, PhD, FRCP, FACC: Heart attacks can occur completely out to the blue and heart attacks can be complicated by immediate, sudden and unexpected death. But the majority of heart attacks are preceded by warning symptoms. So people may have a history of having exertional pain in the chest or in the left arm or tightening in the throat or pain going from the chest down into the tummy occurring with walking or with exertion, worse on cold mornings, worse in very hot weather, when the circulation's a bit stressed, worse after a heavy meal. And then people may have noticed that over a period of a few days, those pains get worse. And then when the heart attack actually occurs, you develop a similar, but very much worse pain. It's often described as like an elephant sitting on my chest. And that pain is associated with breathlessness often with nausea and people will often throw up. It's associated with profuse sweating.
If you start to feel those things or if you've known that you've had a bit of angina over a period of months or years, and it suddenly starts to get worse, that's the time to dial 911 and get yourself to the hospital as quickly as possible. Because it's very easy for us to tell in the hospital if you're having a heart attack, we'd simply do an electrocardiograph or EKG and that will tell us you either are or aren't having one.
Caitlin Whyte: So even with that risk of being unexpected, I mean, who is at risk of having heart attacks in general?
John Mounsey, BM, BCh, PhD, FRCP, FACC: Heart attacks occur in people who are genetically susceptible to heart attack, so they definitely run in families. We can't do anything about our genes though. And a wise cardiologist once said to me, "Genetics is all the things we don't know how to measure," and I think that's certainly true. Heart attacks occur in smokers, nobody should smoke. Heart attacks occur much more commonly in people with very high cholesterol in their blood and in people with diabetes and people with chronic kidney disease and people with other signs of vascular disease like blood pressure and things like that.
So as we go through life, it's worthwhile going to our primary care doctors and having a regular physical so that we know what our cholesterol is. We know whether we have diabetes or not. We know if we have high blood pressure or not. Those are all called risk factors. And if we control risk factors, it dramatically reduces the chance that you're going to have a catastrophic heart attack.
And all of those risk factors are controllable. We can all stop smoking. We can all modify our diet and, if necessary, we can take a medication to reduce our cholesterol. We can control our diabetes. We can control blood pressure. But another big factor, especially in the Southern states, is that there is a large proportion of the population, 30 or 40%, who are grossly overweight. And there's no doubt that obesity contributes to all of these things that lead to heart attacks. So if we could give up smoking, take 10 or 20 pounds off our tummy and exercise, it would dramatically reduce the number of heart attacks that we see. And we see heart attacks very regularly here at UAMS.
And by exercising, I don't mean that you got to put on a pair of shorts and go and work out pumping iron at the gym. A lot of people don't like doing that. A lot of people don't want to do that. And I share that with them, I'm not a gym rat myself. But if you can get out and for 40 minutes, three or four times a week, get out and walk on the river walk in downtown Little Rock or wherever is convenient around you. A walk at a good clip for 30, 40 minutes, apart from anything else, it's fun, it gets you outside, it gets you into the fresh air, but it does wonders for your vascular health. And the more we learn about exercise and weight loss, the more we realize how fundamental they are in preventing heart attacks.
Caitlin Whyte: Well, doctor, some really concrete solid takeaways from this podcast today. Wrapping up here, is there anything else you'd like people to know about heart attacks?
John Mounsey, BM, BCh, PhD, FRCP, FACC: I think the last thing I would really like to people to know about heart attacks is that it's not inevitable that you die of a heart attack. I think if you're having a heart attack, you need to get yourself to the hospital quickly because if you have a blocked coronary artery, we can unblock the coronary artery. We can pop a balloon down the artery, blow the balloon up, put a stent in the coronary artery and we can limit the amount of damage that is done to the heart.
Make no mistake. If you have especially more than one heart attack, you do stand a chance of developing weakness of the heart. And if we can prevent weakness of the heart, we can prevent heart failure. And frankly, we can make you live longer. If you can get your coronary artery opened and take the appropriate medications, you can reduce your chance of dying of a heart attack by more than 50%.
So while heart attacks in our parents' generation were frequently a death sentence, they really aren't. They don't have to be anymore. Sorry, that's a somber note to finish on, but I hope a hopeful one.
Caitlin Whyte: No, I mean, I think it's always a good reminder to know that we are still in control.
John Mounsey, BM, BCh, PhD, FRCP, FACC: Yes. And I think that's right. We have to take control of our vascular risk. But if we're unfortunate enough to develop chest pain, such that we think we might be having a heart attack, we need to get ourselves to a hospital and we need to get it fixed.
Caitlin Whyte: Well, thank you so much doctor for your time and for this valuable information. And thank you for listening today. This has been UAMS Health Talk, the podcast by the University of Arkansas for Medical Sciences. I'm Caitlin Whyte. Stay well.
What Happens During a Heart Attack?
Caitlin Whyte: Heart attacks are unfortunately quite common in the United States. In fact, one happens every 40 seconds here. But what exactly is happening in your body during a heart attack? To tell us more, we are joined by Dr. John Mounsey, the Director of Cardiovascular Service Line, a Professor of Medicine and the Chief of the Division of Cardiology.
This is UAMS Health Talk, the podcast by the University of Arkansas for Medical Sciences. I'm Caitlin Whyte. Now, doctor, let's start with that big question in our intro. What is happening in our bodies during a heart attack?
John Mounsey, BM, BCh, PhD, FRCP, FACC: Okay. So a heart attack occurs when an area of the heart is deprived of its blood supply. If you think about the heart, it's a muscular pump. Actually, it's several muscles and valves and things all loosely joined together, but it's a muscular pump and muscles require energy. They get energy from oxygen and sugar and things in the blood. So the first thing the body does is it pumps blood out to the heart around the body as it looks after the pump. And the two first arteries that come off the aorta, that's the main artery on the top of the heart, are called the coronary arteries because they supply the heart. And the coronary arteries grasp the heart a bit like fingers grasping a baseball and each coronary artery looks after a different bit of heart.
And if there is buildup of plaque or fatty deposits in the walls of the arteries, then they can become blocked. If they'd become partially blocked, you could develop chest pain and we call that angina. If they become completely blocked, then you develop a heart attack and the little bit of heart looked after by that artery dies.
Caitlin Whyte: So what causes a heart attack or causes that buildup?
John Mounsey, BM, BCh, PhD, FRCP, FACC: The buildup of blockages in the arteries around the heart is caused by buildup of cholesterol in the walls of the arteries. In fact, in Western populations, we've known for a long time now that the very first signs of developing cholesterol in the walls of the coronary artery start very young in life and they progress. In people who are prone to developing blocked coronary arteries, they progress through life. And plaques, just minor rufflings in the wall of the artery, can over a period of years develop into blockages.
The actual initiating event of a heart attack or the thing that makes a heart attack such a catastrophic and sudden event is that if you could imagine you've got plaques, which are like narrowings in the walls of the arteries. And if one of those ruptures, then you can go from a narrow artery to a completely blocked artery in a matter of a few seconds. Because if a plaque ruptures, cholesterol leaks out of the block and the body will try and wall that off and form a blood clot or what we call a thrombus inside the coronary artery, and that causes catastrophic and complete blockage of the coronary artery. That's why a heart attack is sometimes called a coronary. You may have heard it called a coronary thrombosis. It means a blood clot in the coronary artery caused by the rupture of a plaque. And it's that catastrophic loss of blood flow to a section of the heart that leads to a heart attack.
Caitlin Whyte: So then what are some symptoms that we can look out for that might signal a heart attack is happening or about to happen?
John Mounsey, BM, BCh, PhD, FRCP, FACC: Heart attacks can occur completely out to the blue and heart attacks can be complicated by immediate, sudden and unexpected death. But the majority of heart attacks are preceded by warning symptoms. So people may have a history of having exertional pain in the chest or in the left arm or tightening in the throat or pain going from the chest down into the tummy occurring with walking or with exertion, worse on cold mornings, worse in very hot weather, when the circulation's a bit stressed, worse after a heavy meal. And then people may have noticed that over a period of a few days, those pains get worse. And then when the heart attack actually occurs, you develop a similar, but very much worse pain. It's often described as like an elephant sitting on my chest. And that pain is associated with breathlessness often with nausea and people will often throw up. It's associated with profuse sweating.
If you start to feel those things or if you've known that you've had a bit of angina over a period of months or years, and it suddenly starts to get worse, that's the time to dial 911 and get yourself to the hospital as quickly as possible. Because it's very easy for us to tell in the hospital if you're having a heart attack, we'd simply do an electrocardiograph or EKG and that will tell us you either are or aren't having one.
Caitlin Whyte: So even with that risk of being unexpected, I mean, who is at risk of having heart attacks in general?
John Mounsey, BM, BCh, PhD, FRCP, FACC: Heart attacks occur in people who are genetically susceptible to heart attack, so they definitely run in families. We can't do anything about our genes though. And a wise cardiologist once said to me, "Genetics is all the things we don't know how to measure," and I think that's certainly true. Heart attacks occur in smokers, nobody should smoke. Heart attacks occur much more commonly in people with very high cholesterol in their blood and in people with diabetes and people with chronic kidney disease and people with other signs of vascular disease like blood pressure and things like that.
So as we go through life, it's worthwhile going to our primary care doctors and having a regular physical so that we know what our cholesterol is. We know whether we have diabetes or not. We know if we have high blood pressure or not. Those are all called risk factors. And if we control risk factors, it dramatically reduces the chance that you're going to have a catastrophic heart attack.
And all of those risk factors are controllable. We can all stop smoking. We can all modify our diet and, if necessary, we can take a medication to reduce our cholesterol. We can control our diabetes. We can control blood pressure. But another big factor, especially in the Southern states, is that there is a large proportion of the population, 30 or 40%, who are grossly overweight. And there's no doubt that obesity contributes to all of these things that lead to heart attacks. So if we could give up smoking, take 10 or 20 pounds off our tummy and exercise, it would dramatically reduce the number of heart attacks that we see. And we see heart attacks very regularly here at UAMS.
And by exercising, I don't mean that you got to put on a pair of shorts and go and work out pumping iron at the gym. A lot of people don't like doing that. A lot of people don't want to do that. And I share that with them, I'm not a gym rat myself. But if you can get out and for 40 minutes, three or four times a week, get out and walk on the river walk in downtown Little Rock or wherever is convenient around you. A walk at a good clip for 30, 40 minutes, apart from anything else, it's fun, it gets you outside, it gets you into the fresh air, but it does wonders for your vascular health. And the more we learn about exercise and weight loss, the more we realize how fundamental they are in preventing heart attacks.
Caitlin Whyte: Well, doctor, some really concrete solid takeaways from this podcast today. Wrapping up here, is there anything else you'd like people to know about heart attacks?
John Mounsey, BM, BCh, PhD, FRCP, FACC: I think the last thing I would really like to people to know about heart attacks is that it's not inevitable that you die of a heart attack. I think if you're having a heart attack, you need to get yourself to the hospital quickly because if you have a blocked coronary artery, we can unblock the coronary artery. We can pop a balloon down the artery, blow the balloon up, put a stent in the coronary artery and we can limit the amount of damage that is done to the heart.
Make no mistake. If you have especially more than one heart attack, you do stand a chance of developing weakness of the heart. And if we can prevent weakness of the heart, we can prevent heart failure. And frankly, we can make you live longer. If you can get your coronary artery opened and take the appropriate medications, you can reduce your chance of dying of a heart attack by more than 50%.
So while heart attacks in our parents' generation were frequently a death sentence, they really aren't. They don't have to be anymore. Sorry, that's a somber note to finish on, but I hope a hopeful one.
Caitlin Whyte: No, I mean, I think it's always a good reminder to know that we are still in control.
John Mounsey, BM, BCh, PhD, FRCP, FACC: Yes. And I think that's right. We have to take control of our vascular risk. But if we're unfortunate enough to develop chest pain, such that we think we might be having a heart attack, we need to get ourselves to a hospital and we need to get it fixed.
Caitlin Whyte: Well, thank you so much doctor for your time and for this valuable information. And thank you for listening today. This has been UAMS Health Talk, the podcast by the University of Arkansas for Medical Sciences. I'm Caitlin Whyte. Stay well.