The brain and the heart are in constant communication, sending signals that control and respond to each other, so it’s no surprise that what’s good for one is what’s good for the other. Dean Robert Harrington, an esteemed cardiologist and the new dean of Weill Cornell Medicine, joins us today to explore the fascinating conversations that go on between these two most important organs. From the electrical signals sent from the brain to the oxygenated blood flow the heart sends back, find out what keeps both organs going—and what happens when something disrupts that balance. Turns out you really can die of a broken heart, as a sudden intense emotional event can cause the brain to send a “stop” message to the heart; a disruption in the heart’s blood flow can send a similar message to the brain.
Phil Stieg: This week, our guest is esteemed cardiologist Dr. Robert Harrington. Dr. Harrington has recently been appointed as Dean of Weill Cornell Medicine, The Stephen and Suzanne Weiss Professor and Provost for Medical Affairs. He brings a wealth of experience from his roles as chair of Stanford’s Department of Medicine and the Clinical Research Institute of Duke University. Not only is Dr. Harrington a member of the American Heart Association’s board of Directors, but he also served as its 83rd president. In this episode, we will gain important and surprising insights into the heart- brain connection.
Bob welcome. And thank you for being here with us today.
Robert Harrington: Thanks for having me. I look forward to the conversation.
Phil Stieg: Explain to us that yin and yang relationship between the heart and the brain. The brain can mess up the heart. The heart can mess up the brain. The brain can help the heart. The heart can help the brain. How does that play?
Robert Harrington: So if I’m thinking about the brain affecting the heart, the heart affecting the brain — let’s take one that interventional cardiologists are very familiar with, and that’s the so called stress induced heart attack the Takasubu’s syndrome or what’s been called the broken heart syndrome.
And this is when a highly stressful event, typically a very emotional event and typically a very sudden event, like a spouse dies. Something is happening in the brain that’s sending signals to the heart that changes the blood flow of the heart so that it looks like a person is having a heart attack. In fact, they are having a heart attack, but it’s a different type of heart attack. It’s a heart attack that when you look at the arteries, there are no blockages.
So somehow the signals from the brain have gotten to the heart to alter the blood flow to the heart. And now you’re in a situation where the heart’s dying. Fortunately, some of these, many of these, get better. But it’s pretty dramatic when you see it and you do all the things that you do as cardiologists when somebody’s having a heart attack.
Likewise, we see people who have an incredibly emotional event, and they have sudden cardiac death. They die, their heart stops. It goes into rapid ventricular fibrillation.
So there are signals that are being sent, whether it’s from stress, response to grief, response to a highly emotional situation that some chemical in the brain is being sent to the heart, altering blood flow, altering electrical impulses. And that has been, to me, one of the “Aha!”s of connecting the brain to the heart.
Now, the other way, how does it go the other way, heart to brain? A lot of that is through the blood pressure and a lot of that is through things like atrial fibrillation, irregular heartbeats where blood clots are forming in the heart and going up to the brain. So, yeah, a lot of things that affect the brain affect the heart, and affecting the heart affects the brain.
Phil Steig: I can imagine people are listening to this and thinking, “wait a minute. My job is stressful!”
Robert Harrington: Yeah.
Phil Steig: Is this at all job-related? Can it be?
Robert Harrington: It’s more of a very acute stress and usually something really tragic.
Phil Steig: So let’s talk a little bit about the chronic stress associated with anything in our lives. How does that affect both the heart and the brain?
Robert Harrington: Yeah, so let’s go through that. We know that chronic stress, be it a job, personal situations, life can lead to strain on the heart in a number of ways, one of which is elevated blood pressure. And consistently elevated blood pressure can certainly lead to overload of the heart, thickening of the heart muscle and conditions like heart failure where the heart’s just not able to pump like it should.
We also know that chronic stress can be linked to coronary artery disease, to the atherosclerosis that builds up probably also from a bit of the same thing like hypertension, chronic vasoconstriction or narrowing of the vessels.
We also know that stress travels with other risk factors smoking, overeating, lack of exercise. All of that interplay are the kind of things that can lead to heart disease. Narrowing of the arteries, damage to the heart muscle. Flip that around to the brain — similar biologic process, narrowing of the blood vessels, feeding blood to the brain can get affected with the atherosclerotic process with the buildup of plaque, stress, cigarette smoking, obesity, overweight, not eating well, not exercising.
So there is this relationship that some of the same risk factors that affect our heart health also affect our brain health.
Phil Steig: Emotions go up or emotions go down. You pick. What will that do to the heart?
Robert Harrington: Does a lot of things. I mean, we’ve all probably been in situations – giving a big speech, heart rate goes up, tachycardia. And that’s on an unpleasant situation. Sometimes people have stage fright. And that’s a well-known issue of connecting the brain to the heart. That notion of distress, that notion of nervousness, some of that is good. One performs better. If you have a little bit of racing heart, a little bit of elevated blood pressure, you perform better. But some of that can be deleterious. And as you know, actors, public speakers, sometimes even take heart medicine to slow down the heart rate, to slow down that feeling of anxiety when one has to perform.
Phil Steig: I’ve known people that have taken, what, Inderal, which is something that regulates the heart just prior to a speech.
Robert Harrington: Yeah, propranolol or Inderal is one of the first of the so called beta blockers. Slows down the heart rate, slows down the, lowers the blood pressure a little bit, provides a sense of calmness because it takes away the stuff that makes you anxious: the rapid heart rate, the elevated blood pressure, the sweating. And there are a number of well-known people who — actors, performers, people in yours and my profession.
Phil Steig: But you wouldn’t recommend it for an athlete, would you?
Robert Harrington: I would not recommend it for an athlete – they need that response. Remember that cardiac output is the function, how much your heart pumps is a function of only two things how much volume is in the heart and your heart rate. Heart rate times stroke volume gives you your cardiac output. You don’t want to slow the heart rate too much in order to have a good cardiac output.
Phil Steig: When I was thinking about this, the question that came to my mind is, what about a heart transplant person? How is their heart affected by their emotion?
Robert Harrington: Well, great question. And as a surgeon, you’ll appreciate that when the cardiothoracic surgeons remove the heart and the blood vessels, they in fact have severed the nerves. And so one of the more interesting, it’s always a great cardiac board question or a question on rounds to share with the students and the residents when you show them the different pacemakers of the heart, that you may have remnants of the old pacemaker and the new pacemaker from the new heart. And so you’ll see on the EKG the two pacemakers in a transplanted heart, not always, but you’ll see it frequently.
Phil Steig: Do they have the same response to emotional input? Because that’s been cut also, I guess.
Robert Harrington: You can still see the tachycardia response to stress. You can still see the changes in blood pressure. What I don’t know — t’s actually a really good question — I don’t know if anybody’s actually reported Takasubu’s in a transplanted heart. I’ll look that one up later.
Phil Steig: So when you transplant a heart, what I don’t understand is, since all the nervous input from the brain and the sympathetic system and all that has been cut, how does the heart function properly?
Robert Harrington: It’s that internal pacemaker system. Remember, the heart in many ways… how do I say this about the organ that I love so much? The heart in many ways is very simple. It’s a pump, and as a pump, it requires electricity. And if that electrical system is working and the muscle is strong, it’ll do its thing. On the other hand, the organ that I love so much is very complicated.
Phil Steig: I used to hate referring to the brain as a muscle, but the reality of it is, the more that you use specific neural networks, the better they develop, just like the heart.
Robert Harrington: The heart’s pretty simple in that way. The brain is complicated. I don’t know anything about the brain.
Phil Steig: What are your thoughts about two glasses of red wine a day?
Robert Harrington: You mean personally or professionally?
Phil Steig: Both! (laugh)
Robert Harrington: Personally, I highly approve. (laugh)
Professionally, there was this notion of the French paradox, that there was less heart disease amongst the French who drank a fair bit of red wine on a population average. And there was a lot of work done about how much alcohol was not just safe, but potentially helpful to your heart health.
And in particular, there was a huge amount of research that went into, was it red wine specifically with certain chemicals in it that made it red, that was beneficial? Companies started to extract those chemicals and potentially use those as therapeutics.
Fast forward now a couple of decades. And what we know is that probably modest amounts or moderate amounts of alcohol are healthy for you, meaning that they’re not increasing your heart risk and may have other beneficial effects like reducing stress, et cetera.
But I hate to tell your audience this. There is also some evidence that maybe there’s no threshold of helpful alcohol. Now, I put it in the context, I’ll go back now to my personal opinion is that everything in life is a balance. And if you can reduce some stress, get some relaxation out of a glass or two of wine, I’m all for it.
Phil Steig: Are you a devotee of meditation?
Robert Harrington: Yeah, so I am not a devotee of meditation, but I have many patients over the years who are, and I’ve worked at a few places, in particularly at Duke, where there was actually a high emphasis on things like meditation as a way to reduce stress.
There was actually a very famous investigator at Duke who was very interested in the relationship between stress and, in particular, anger and heart disease. And some of the things that people would counsel patients on was using things like transcendental meditation, using biofeedback, just taking that moment, that pause. My sense is that that’s a good thing for you. Again, it gets it, I think, where you’re going here, our brain…
Phil Steig: Well, the cognitive thing, too, because, I mean, there’s evidence that with meditation, the brain changes.
Robert Harrington: Yeah. And I think that there’s pretty good evidence the heart rate slows down, the heart muscle pumps a little more effectively, people feel better.
Phil Steig: With the aging population, more people are experiencing atrial fibrillation and obviously the link between that and stroke. What are your thoughts about that and the management of it?
Robert Harrington: Yeah. So in full disclosure this is where I do a lot of my research.
Atrial fibrillation is chaotic electrical activity bombarding the lower chambers. And in an irregular way, some of those beats make their way through. Why is that bad? Or why is that a concern? Number one, people feel bad. They don’t have the upper chamber contributing to the lower chamber contraction. That upper chamber, lower chamber connection contributes ten to 15% of your cardiac output. So let’s say for the sake of argument, you’re in atrial fibrillation and at rest you feel fine. You need to do a little exercise, you might not feel so fine because you’ve lost that 10-15 percent cardiac output.
The second big thing, and you’ve alluded to it, is that in that chaotically firing, atria, blood clots can form. Blood clots can get dislodged. And where do they go? They go to other parts of the body. Most notably, they can go to the brain. And so a fair bit of stroke, as you know, can be caused by blood clots in atrial fibrillation.
But here’s the good news, is that we’ve known for many, many years now that use of the blood thinners, first with medicines like Warfarin or Coumadin, reduce the risk of stroke in atrial fibrillation patients by almost 70%. You know this there’s nothing in medicine, very few things that work that well, but blood thinners in stroke do. And then secondly, there were a new group of medicines in the last decade-plus, the factor ten inhibitors, that reduced the risk of stroke even further than the Coumadin and Warfarin like drugs and can do it in a safer way.
Phil Steig: Give our listeners some perspective. How many people do you think are walking around in atrial fibrillation? They haven’t been to a doctor, and they don’t know it.
Robert Harrington: And I’ll give you my favorite answer. It depends, and it depends upon what their underlying risk is. So let’s take a 70 year old. For a 70 year old, we think that it’s somewhere probably in the three, four, 5% range. In the 20 year old, it’s less than 1%. So it’s highly dependent on your age and other cardiac risk factors like high blood pressure.
But the older we get, you’re looking at incidents of atrial fibrillation at about 65 to 70, there’s a sharp inflection. By the time we’re over 75, about one in six of us will have atrial fibrillation, the majority of which is symptomatic. And so it’s picked up. But there is a small group. We actually did in my former life, you had mentioned I was the chair of medicine at Stanford. We did this large study and published it in the New England Journal of Medicine. 500,000 or so individuals who had no history of atrial fibrillation wore the Apple Watch and about, in the highest risk group, meaning the older group of patients, about three or 4% of the patients had undetected atrial fibrillation.
Phil Steig: If I ask you to give five rules that a person should live by for good heart and brain health…
Robert Harrington: Yeah, I’ll give you two right off the top of my head. Here’s the two things; The older I get, the more interested I get in the public health, in addition to sort of the personal, patient-oriented health. If we could do two things in this world to make the biggest, quickest difference in the risk of heart disease and stroke – stop smoking. Get rid of tobacco globally, and we will have a huge effect.
Phil Steig: That’s still a problem?
Robert Harrington: Oh, my God. It still is on a global basis.
Phil Steig: Because I don’t see anybody smoking anywhere? But I see a lot of vapes…
Robert Harrington: Let’s come back to that in a minute. Okay, but stop smoking.
Phil Steig: All right.
Robert Harrington: Have you been to China? Everybody’s smoking, and they’re smoking like we did in the United States in the 50s and 60s. So we have driven down our adult smoking rates, but we still see there’s some health inequities here. Lower socioeconomic groups smoke more than people who are better off from a socioeconomic perspective.
Phil Steig: And teen smoking is on the rise, isn’t it?
Robert Harrington: We got teen smoking down, meaning we as a society got teen smoking down extremely low. When you and I went to high school, 25-30% of high school seniors smoked. In my own high school, there was a smoking yard where you could go outside and smoke during your break in high school. Fortunately, those things are a vestige of the past, and I’ll come back to the vaping. In a moment. The second thing, control blood pressure. If we could control the globe’s blood pressure and we could get rid of tobacco, we would save millions of lives. Millions of lives.
Okay. All right, so let’s go to the vaping question.
Phil Steig: Yeah.
Robert Harrington: The short answer is we don’t know all the details about vaping in a variety of things. First off, we don’t know is it an effective smoking cessation device. People say, well, I’m not smoking cigarettes anymore, but I’m vaping. Well, what we don’t know was that trade off worth it? From a health perspective, there’s just not been enough of the large scale data might be. And from a heart association perspective, we love to see the studies that do that. Secondly, we do know that vaping is not without its physiologic prices. It causes vasoconstrictions narrowing of the blood vessels. We don’t know whether or not nicotine, whether it’s inhaled or ingested, does it have a long term deleterious effect on blood vessels. So there’s a lot we just don’t know. But it is alarming that kids in particular are picking up vaping at, like, record paces. And why is that bad? Number one, we don’t know the effects. We don’t know the effect on the brain of chronic nicotine exposure. And then the final thing is we know that if they don’t have access to vape and they’re addicted to nicotine, what do they do? They turn to combustible cigarettes, and they smoke.
Phil Steig: I want to turn this around a little bit of your role as a dean and a public health guru. You alluded to it a little bit earlier. Let’s talk about the implications. If we don’t do a better job in heart and brain health, what’s it going to mean for our insurance companies, for our public health programs and Medicare?
Robert Harrington: Life expectancy in this country has dropped over the last few years. Risk of dying from heart disease has increased, and it’s because we’re not getting under control a lot of what I would call the chronic disease precipitants, in particular weight, physical activity, diabetes. That triad there is really causing havoc with our life expectancy. And so if you go back to–
Phil Steig: And those diseases affect which organs?
Robert Harrington: Yeah, the heart and the brain. And so what is that going to mean as a society? Is that as you start having more and more of these chronic diseases, as people are dying at earlier ages, you have all sorts of implications on the workforce, on insurance. You know that our hospitals are always filled. That’s a problem.
Phil Steig: How we’re going to solve this problem? I see it as becoming overwhelming. If we have an obese young generation, they’re going to have so many bad diseases, we won’t be around long enough to see it happen. It’s going to happen in 40 years but…
Robert Harrington: Well, even though I’ve only been here two and a half months, you’ve probably noted that I’m eternally optimistic. I think there are a lot of things we can do. I think that public advocacy is going to be a critical part. People like you and I talking to a large audience. I do think these things are important to transmit messages that are good for the public health, get people thinking. So I think that’s part of my role leading a medical college is that we need to be talking about these things from a societal perspective.
And I don’t want to default to drug therapy because, boy, I haven’t given up on lifestyle. But there’s this whole new class of drugs, the so called GLP one agonists, which you talk about heart, brain connection, that definitely is doing something in the brain. It’s probably doing something in the gut. People don’t feel as hungry. They’re not eating as much. And guess what? They’re losing a lot of weight. Well, that’s important. But guess what’s also happening? They’re having less heart attacks and strokes. That’s fascinating.
Phil Steig: But is there something about the American society where you got a drug boom, everybody jumps on it? And how do we engage patients, people, to realize that with relatively simple modifiers in their life, they’re going to live longer and healthier?
Robert Harrington: Yeah. You know what the exercise prescription is from the Heart Association and from the US. Surgeon General?
Phil Steig: I’m afraid to ask.
Robert Harrington: 30 minutes of walking five days a week. That’s it. We’re not asking people to climb mountains. We’re not asking people to ride bikes for hundreds of miles. If you want to do that, more power to you. What we’re asking for is 30 minutes a day, five days a week. Best thing that’s happened to me, being in New York City, I walk 15 to 20 minutes to work and home every day. And so I get another 30 to 40 minutes of exercise just walking. And I’ve noticed the difference.
Phil Steig: And you only live a block away from the hospital.
Robert Harrington: That’s because I’m stopping to talk to everybody.
Phil Steig: I’ve interviewed some people on the show that obviously think that exercise is like the cure for almost everything, which it probably is to a degree. What does exercise specifically do to stress?
Robert Harrington: Good data on this. Exercise reduces stress. People who have been exercising experience better quality of life and it’s probably multifactorial that when you exercise, particularly when you exercise at a certain level, you release endorphins, which make us feel good. What’s it called, the runner’s high. I was a track runner in college, ran for many, many years until my knees gave out, but ran for many, many years. And there is that sense that when you’re just flying along down a path in the woods, wow.
So you do get these chemicals released that make your brain feel good, and that’s a good thing. We know that exercise will lower blood pressure. We know that it slows the heart rate. We know that it’s going to be associated with less heart failure, weakening of the heart. So exercise does so many good things. It strengthens the muscles, particularly the big muscles. When people ask me about, why does walking help? Because you get the big muscles, your legs, your butt, your pelvis, those are the big muscles. And guess what? Those muscles use a lot of oxygen. Where does the oxygen come from?
Comes from the heart through blood. And so if you can make the muscle use oxygen more efficiently, the heart has to work less hard.
Phil Steig: The interesting aspect, however, is the fact that the brain has its own survival as its primary function. And it tells you not to exercise because you’re taking the sugar away from the brain.
Robert Harrington: Yeah, and there’s all these things about what’s the proper amount to eat and drink if you’re exercising a lot. So, yeah, all that weighs in. But on average as a population, we’re better off to exercise than not.
Phil Steig: We’ll do one more question — can you really drive home the importance between a healthy heart and sustaining our cognitive function?
Robert Harrington: Yeah. So all the risk factors we’ve been talking about for an unhealthy heart, blood pressure, smoking, lack of physical activity, those all have an effect, a direct effect on the brain as well. That’s leading to some of the dementias. That’s leading to strokes. That’s leading to different diseases of the brain. So the things you want to do to protect your heart are absolutely protecting your brain.
Phil Steig: Bob, thank you so much for being with us today. I’ve learned an immense amount. We’ve had a chance to talk about the importance of the heart brain connection. But more importantly, you’ve done a superb job of convincing people that leading a heart healthy life is good for their overall health. And that’s the message that we’ve got to keep pounding away in our society. Thank you so much for doing that.
Robert Harrington: Thanks for having me. And thanks for delivering that message. Heart health is brain health, and they both together are total health. So thank you!
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