Episode Transcript
[00:00:05] Speaker A: The Michael Hatfield re Max team presents real estate and more.
[00:00:11] Speaker B: Bay Area real estate is different than in all of America. And why? What's up with homebuyers? What's on sellers minds? How is the market? And much, much more.
[00:00:22] Speaker A: Now here's your host, Michael Hatfield.
Well, welcome to the real estate and more show. Thank you for listening this morning. Today I have one of my all time favorite people on the show once again to share with us the latest research, treatment, and surgical techniques on the heart rhythm ailment, atrial fibrillation. We are blessed to have Doctor Kumendor Srivatsan, world class cardiologist from the Mayo Clinic. The Mayo Clinic happens to be the number one ranked medical institution in the United States. And this gentleman is known affectionately by all as Doctor Sri. By the way he lectures all over the world in matters concerning the human heart. I am very grateful to have him on the show once again. Welcome to the show, Doctor Srbatson.
[00:01:12] Speaker C: Thank you, Michael. Thank you for inviting me. It's a privilege.
[00:01:16] Speaker A: Now, we were going to focus today on atrial fibrillation. It's something that affects the entire population much more than what we believe it to be. And there's different types of Afib. Can you share what those types are?
[00:01:30] Speaker C: The most common is paroxysmal atrial fibrillation, which essentially means intermittent.
It comes on and you feel lightheaded, the heart is raising or dizzy, or sometimes you can have some chest discomfort or shortness of breath. Then it goes away on its own. The duration can last minutes to sec, you know, to hours, and sometimes it can go on for days. But once it crosses the seven day barrier, we call it as persistent atrial fibrillation, meaning it doesn't want to go back on its own to the regular rhythm. Now, if the rhythm is persistent in that phase for one year or greater, it's called longstanding persistent atrial fibrillation. And the physician may decide not to pursue restoring regular rhythm because the his ability in his ability and the patient's status, it may be futile or not clinically appropriate, in which case it also could be called permanent atrial fibrillation.
[00:02:38] Speaker A: What are some of the causal factors that could cause this to happen in a person?
[00:02:43] Speaker C: Is the most common cause in the United States is hypertension.
50 million Americans have high blood pressure, and it is an asymptomatic killer because it doesn't produce symptoms unless you go to the doctor's office regularly, once a year at least, to get some numbers measured. The second most common cause is weight gain, body mass index, or as we call it, if it's greater than 30, it increases sleep apnea, which is snoring very heavily. And quitting to breathe at night is a big problem. And if your spouse is complaining of snoring, it's probably worthwhile getting investigated. And, of course, alcohol excess, it can sometimes. It's called the holiday heart syndrome, and people go on vacation and drink a lot of alcohol. Actually, there's a medical term called gamma alcoholism, where people don't drink on a day to day basis, but on a weekend or on a trip with friends, they just drink excessive amount, like eight to twelve beers or whatever equivalent, and then they subsequently develop atrial fibrillation. But chronic excess consumption, exceeding one to two glasses of wine a day, can actually lead to atrial fibrillation and sometimes hyperthyroidism, where the thyroid gland is overactive.
Any surgery, particularly chest surgery, increases the risk of atrial fibrillation. So a variety of factors, but by and large, the single most important factor is either unrecognized hypertension or treated hypertension.
[00:04:31] Speaker A: Now, I believe that there's a playbook that the Mayo Clinic has that you probably apply with each patient that may come in to see you. It's a playbook that says, okay, well, let's try this, and let's try that. And how do you address it? And what is your playbook? Doctor Sri?
[00:04:49] Speaker C: Yes. I mean, most people, by the time they come to an electrophysiologist, they've been through an internist, a cardiologist, and then they get referred to us for electrophysiology, because the symptom burden is quite significant, that the patient is experiencing recurrent ER visits, hospitalizations, or failed medications such as beta blockers. Now, what should we do to improve the patient? One is to improve the symptoms. The second is to make sure there are no stroke effects, and thirdly, to prolong longevity, or at least replicate what got given longevity is, I mean, not adversely influenced by the atrial fibrillation. So in majority of people, the first thing we will do, or most physicians will do, is initiate a blood thinner to make sure that the stroke risk, which is increased somewhere between four to five folds compared to people in regular rhythm, is reduced.
And the second thing is, we'll try to control the symptoms. And the symptoms are usually controlled either with beta blockers or more likely, what I call antiarrhythmic medications.
We may have been familiar with terms like flaconide, propafenone, dofadilide, or amiodrone. These are kind of pills, which control the rhythm to a large extent.
However, the 2023 guideline has said that there's no need to wait for drug failures. You can directly go and do perform an ablation. An ablation is a procedure where the physician threads a catheter like similar to the angiogram catheter, but a little bit more made up of wires, which can deliver energy, like electrocautery energy or freezing cooling energy, to disrupt the pathways through which a fibrillation spread in the heart. So there are variety of steps we take first to make sure that the patient's stroke reduction is reduced, the symptom burden is reduced.
And thirdly, we want to restore regular rhythm to maintain their longevity, which is especially if they're in heart failure, such as shortness of breath or low pumping ability of the heart, it becomes more incumbent to restore the regular rhythm.
[00:07:10] Speaker A: Afib, I understand, is the most common arrhythmia diagnosed in clinical practice. And estimates of AFib in the US range from about 2.7 to 6.1 million of our population. And that number is expected to rise to 12.1 million in 2030. What are your thoughts as to why the number may rise in the population of the United States to that big number in 2030?
What would generate that type of an increase in atrial fibrillation?
[00:07:50] Speaker C: Yeah, that's a very good question. It's a population problem. So now we let us look at the current state of affairs. Somewhere around 3.5 million people have diagnosed atrial fibrillation.
There is supposedly 8 million people totally, who have Afib but don't even know it, or either their apple Watch is recording and they're waiting, or some form of variable is recording it and somebody has not yet interpreted it or not confirmed it. Then we have a condition called pre atrial fibrillation, which is having a lot of extra beats and what we call non sustained atrial tachycardia. This may affect 15 to 18 million of the population. So we have the effect of high blood pressure, which is 50 million, is affecting about a third of the population, with some form of disturbance in the rhythm problems. The reason is the heart is getting stretched, and each muscle fiber is part of an electrical circuit. And when they break down, the electricity can spin around these broken down spots, causing atrial fibrillation. Besides, the most seminal work was done from France by Doctor Hessiger, who said the most atrial fibrillation is by rapid firing from the veins that bring blood back into the lung, called pulmonary veins. Pulmonary is basically lung, and lung veins on the mouth of them, there are cells which are firing away at rapid speed. That was his seminal work. But also, hypertension, being so associated with atrial fibrillation, can cause all the valve of heart disease. Supposing mitral valve is leaking, which is the second most common valve problem in the United States, called mitral valve prolapse, or myxomerus. Mittal valve is the official term. When you leak blood back into the left atrium, the atrium is getting stretched, and that also can break down the fibers of Alvalo. Heart disease is the another cause for atrial fibrillation. So we can see atrial fibrillation is becoming much more common as we start having much and more and more hypertension plus weight gain, which essentially means the heart, which was designed to supply.
Let me use an auto analogy. Like, if you have a four cylinder engine and asked to do a six cylinder work, because you've gained about one and a half percent's weight, then the heart is bound to experience some rhythm problems or sputtering collateral fibrillation.
[00:10:31] Speaker A: If someone comes to you, you analyze. After they've been through the process of a couple ER visits, and they've seen their own doctor numerous times and their own cardiologists, they come to the Mayo clinic, and they see an electrophysiologist that analyzes it. You use a playbook that says, okay, well, you know, we're going to try these medications, antiarrhythmic.
If they don't work, eventually down the road, you're requesting that you lose a little bit of weight, you exercise, you get your blood pressure under control, then it comes down to the ablation. With ablation, there's several different types of ablation. I understand. And what is the ablation? What do you, what actually is done in an ablation procedure? And what types of procedures are, are used with, with that procedure?
[00:11:21] Speaker C: Yeah, it's a very good question. First, we have a source of the arrhythmia, which is generally accepted as the mouth of the lung veins or the pulmonary veins. Now, in the very beginning, we were directly targeting the source, and what happened was the mouth veins didn't like the heat energy, and they started shrinking in size, preventing the blood from coming back into the heart, causing pulmonary vein stenosis. So then if we don't like people, we put them in prison and build a wall around them so they can't get out. And so why not contain these things from getting into the atrium, rather than actually going into the vein and destroying the cells? So, essentially, today, we build a barrier around the mouth veins, about 5 mm, which is about one fifth of an inch away, so that the vein itself is not narrow, and we create a barrier. The tissue destruction causes scar. And the scar, which is kind of visible, but very small area of the heart. And the scar prevents, because it has different conductile properties, it prevents the electricity from the veins getting into the atrium as such. Now, the way we can deliver this energy to create the scar around the mouth of these veins, for normal people, have four lung veins. One is from each upper lung and lower lung for left and the right. So it'll be four veins. We create a barrier. The scar tissue can be caused by originally what's called thermal ablation, which is radio frequency energy, which is basically taking our home electricity, but increasing the frequencies. So the heart does not actually see the electricity, but it becomes a conducting wire, and it heats up and it destroys the tissue. Now, you can also freeze.
Freezing is taking it to -80 degrees. And essentially what happens, the water in the cells crystallizes, breaking the cell membrane. And you can, you know, if you always shoot the person twice or the animal is really dead, so you thaw and then refreeze. And therefore, the recurrence rates are really low because there are some cells that can withstand a frostbite, basically, and therefore, use refreeze again to make sure that area is completely not able to conduct electricity. Now, all these issues produced some collateral problems, albeit in very small number of patients. It was producing collateral problems in about 0.5% to 1% of the people, which was of significant magnitude. So we came up with a newer energy form, which is just approved by the FDA in the United States, although available in Europe for 18 months, called the pulse field ablation, which is a form of mini electrical shocks that you deliver near the cells. And what happens? The cells don't like these shocks, and they open up a lot of pores and membranes.
That leads to disturbance. In that homeostasis, the wall is kind of has too many pores, and ion channels open up, unwanted chemicals get in, destroy the cellular function, and therefore, the cell is gradually replaced by fibrosis. Now, the main advantage of this method, collateral damage, such as esophageal effects, are close to zero. So I think the energy modalities are constantly improving. There was in between two other things came, but they left. One is a laser. The other is high intensity focused ultrasound. Both of them did not add advantage or value. So today we have thermal ablation versus non thermal ablation, such as pulse field ablation. Wow.
[00:15:33] Speaker A: The time that it takes to do one of these procedures has reduced over the years?
[00:15:38] Speaker C: Absolutely. I mean, in the very first time I did it in 2001 or 2003, it was taking me 6 hours minimum. That is my time for the patient looked like 8 hours because they are under anesthesia before and after for a little bit. And today, with just a thermal ablation, like radiofrequency or cryo ablation, we can do it in an hour and 30 minutes to 2 hours. But with pulse field ablation, the Europeans are publishing that they are doing it in 55 minutes procedure duration. So really it has come down quite a bit. So in the. In Mayo clinic format, we always repeat a the map, even though it adds additional 1015 minutes. We want to make sure there are no gaps in our areas of electrical isolation, as we call it, because we're creating barriers. We don't want leak in our barriers. We actually Remap has shown there are some energy forms don't produce a solid barrier. And you may have to do what's called touch up in these areas to make sure, fortify those areas, to make sure that the patient. Our goal is the patient should not experience a recurrence. In spite of all these technology, it's not a hundred percent cure procedure. In a paroxysmal afib, we can claim 80% to 85% of people in early phases can have symptom relief for at least a year, although there's some tapering, but time away from the procedure.
But in persistent and permanent atrial fibrillation, the efficacy rates are somewhat lower.
[00:17:23] Speaker A: A number of years back, I believe you gained preeminence in your field by leading a clinical study of more than 140,000 Mayo heart patients. And you determined, as a result of this clinical study, that there was a correlation between people that have hiatal hernia and atrial fibrillation. And you extracted other information from that research also. Is that not correct?
[00:17:53] Speaker C: Yeah, absolutely. So, yeah, we all. We felt that patients with haia dysrnia was repeatedly presenting with atrial fibrillation, anecdotally. So we wanted to see our database and as you pointed out, collected some astronomical numbers of patients with hiatal hernia presenting to Mayo Clinic over ten year period.
Now, what we wanted to know was, is the percentage of AFib higher in this population than a population which does not have higher dysrnia? And we found there was a significantly higher percentage, two and a half fold in the increase in the number of patients with the atrial fibrillation. And we also had this concern about doing an ablation on them, because the esophagus is. The stomach is somewhat prolapsing. But we found that through multiple electrode monitoring within the esophagus that the ablation procedures in these patients is relatively safe to perform. So that was a study we published, that the atrial fibrillation percentage is much higher in patients with hiatal hernia. One of the speculative theories that we had was the esophagus and the heart share the same nerve supply, and the sympathetic nervous system, which is the one, the flight and flight response system and the relaxed system, the parasympathetic nervous system, they both innervate the esophagus and the heart from the same region. And therefore, any stimulation of the esophagus increases the risk of electrical modulation of the heart. And that, in turn leads to atrial fibrillation. It's our theoretical construct of why this increases in hiatal hernia patients.
[00:19:48] Speaker A: Yeah. Is that because of, or is it near where the vagus nerve comes from the back of your brain and it goes down alongside the esophagus and it touches on every organ all the way down to the bladder and so forth. And it goes right through that diaphragm, does it not, in the chest?
[00:20:07] Speaker C: Absolutely. You're right. I mean, the vagus nerve takes care of the heart, and the upper intestines, the mostly urinary bladder and the urogenital system have an independent vagal or autonomic nervous system coming from the lumbosacral region.
There's a specialized we have, we always call a sympathetic nervous system as a thoracolumbar outflow, and the parasympathetic nervous system as a craniosacral outflow. And the. The sacral is largely for genetic genital areas, so that there's an independent activity there. But for the vagus nerve, up the entire chest, upper part of the stomach and small bowel, the vagus nerve is predominantly supplying there to regulate motility. And as well as, you know, all this fullness and satiety and so on, these are all carried back to the brain for interpretation by the vagus nerve. It also happens to innervate the heart. It slows down your heart rate when you're happy and relaxed, and it certainly with the draws, when you're excited or angry, upset or exercising, then the heart rate goes up through the sympathetic nervous system. So there's a break, and then there is a stimulant for the heart rate. And this imbalance caused by the vagus, the vagus nerve, especially when the esophagus is stimulated by the prolapsed hiatal hernia, in turn disrupts the electrical flow of the heart, causing atrial fibrillation. The. When you are calm and relaxed, the heart rate slows down by the vagus nerve. Now, that is to. When you're relaxed, you don't need a lot of cardiac output. When your engine is idling, you don't want to beat so fast, so to speak. When you really have to climb up a mountain, you want the highest rpm, and that's when the sympathetic nervous system comes in. But it also has another dual role. When you take a breath in, the oxygen is in the lung at that time, and you want a slower transit time for the blood to get more oxygen. When you're breathing out, there's no need to really supply a lot of blood into the lungs at that time. So the heart rate fluctuates with breathing.
There's a very nice scientist who described this, called the herring brewer reflux, that the heart rate slows down by the vagus when you breathe in. And when you breathe out, the vagus nerve withdraws itself and therefore you see the heart rate increases. And the whole idea was transitioning this oxygen as well as when you are exercising or angry or upset, the sympathetic nervous system increases the heart rate. When you're relaxing, the vagus nerve slows it down. So there is a balance between these two constantly. The intrinsic heart rate, which is the absence of influence of this nervous system, is unknowable in a living, normal person.
What is the actual heart rate that one has without the influence of these nervous systems? But in the lab, we can give medicines to block both systems and see what is the intrinsic heart rate. But that's rarely done because mostly for experimental reasons, but it doesn't have a lot of clinical implication. But I just want to make sure the viewer or the listener understands that there is an intrinsic artery, but it's always modulated between the balance between these two systems.
[00:23:42] Speaker A: So what would you like to finish with, Doctor Sri?
[00:23:46] Speaker C: Yeah, I would like to say a few things. First, carbohydrate restriction is the single most important reason for weight loss. I'm not saying that you can eat protein willy nilly, but eat protein in moderation, but carbohydrate, minimize them in whatever form, whether it's liquid forms or is in solid form, and bread or pasta or whatever, just taste it, but don't eat too much of it.
[00:24:17] Speaker A: Oh, I hate to say that.
[00:24:20] Speaker C: Number two, make sure exercise is somehow incorporated for a day. I think every, each and every individual need to turn their phones off for an hour a day and focus only on exercise during that period. The third thing is emotional reaction to events. I think the. The biggest problem is we all get wired up too much. I think there are things that you can control on, alter, and do your fullest that is possible. But anything that is left to a third party to control or act and you can control their activity and their thought process best is to leave it to nature, because reacting to somebody else's act or thought or expression is only going to upset you at the end and without.
And the other person is probably immune from all this because they're not worried about what your reaction is. The best thing is protect yourself. What you can change, you change. And what you cannot influence or change, just accept it and move on. That the way the world operates this way, I think that these three things, restricting calories and exercise, for me, time, and then not to react to every little thing that happens around you, which you don't have any control, will really put life in a much better position than where we are in this modern world. We have to get used to these three things.
[00:25:57] Speaker A: This morning has brought forth a wealth of information and education from one of the world's top cardiologists. So with a focus on atrial fibrillation, a widespread disease affecting our population, Doctor Sri, the Mayo clinic, they've done amazing, amazing work there, and he's so generously devoted time for our listeners this morning. Thank you, Doctor Sri.
[00:26:24] Speaker C: Thank you so much. Thank you for inviting me.
[00:27:02] Speaker A: Sadeena. Sadeena.
