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Dr. Miller: Atrial fibrillation and stroke, are they related and can it be treated? Today on Scope radio, this is Dr. Tom Miller.

Narrator: Medical news and research from University Utah physicians and specials you can use for a happier, healthier life. You are listening to the Scope.

Dr. Miller: I am here today with Dr. Dana DeWitt. She is a professor in neurology and a stroke specialist in the University of Utah, the department of Neurology. Dana, tell us a little bit but atrial fibrillation, what is it and does it lead to stroke? Can it cause stroke?

Dr. DeWitt: Atrial fibrillation is an irregular heartbeat. It causes a portion of the heart, called atrium to contract in a very irregular manner and when that happens, clot can form in that portion of the heart and break off and go up to the brain and cause a stroke. It is clearly a major risk factor for stroke.

Dr. Miller: Atrial fibrillation, in my experience, is more common in older patients and older people, and sometimes goes unnoticed. Many times its picked up on a routine physical and sometimes in E.K.G. or patients who complain of palpitations which when you look into it, turns out to be atrial fibrillation. The issue that I have is, in telling the patient, well it's not just this irregular heart rhythm but you might have a stroke down the road if we don't take care of this. In your experience, how many of these strokes that you see, when they come in through the emergency room due to atrial fibrillation.

Dr. DeWitt: It's a fairly large proportion, probably a quarter at least. The hard part is that in many cases, patients will come in and having had a stroke, not have atrial fibrillation at the time so the atrial fibrillation can be intermittent and can sometimes be difficult to detect.

Dr. Miller: How do we detect for atrial fibrillation nowadays? What's the best way?

Dr. DeWitt: When the patient comes in and he has had a stroke, they are usually in a hospital with a cardiac monitor that watches their heart rhythm during that hospitalization. The problem is that the atrial fibrillation may not be detected during that time and so we may recommend, what we call the 30 day event monitor, which is an E.K.G. monitor that they wear for 30 days. There are also things that are called loop recorders which are these very small implantable devices that are M.R.I. compatible and they are put in by the cardiologist just over the heart with a very minor office procedure, and it monitors your heart over time.

Dr. Miller: So potentially, it can pick up intermit atrial fibrillation.

Dr. DeWitt: Exactly, which carries a high risk of stroke.

Dr. Miller: Now, many of our patients and public know that to prevent a stroke, you take an aspirin a day. Does that work to prevent stroke in atrial fibrillation?

Dr. DeWitt: It has not proven to be effective enough in patients with atrial fibrillation. The best treatment are blood thinners, and now blood thinners come in two different forms. There is a drug called Warfarin which is being used for many, many years.

Dr. Miller: That's rat poison. Isn't it?

Dr. DeWitt: It is rat poison and it is the primary treatment for atrial fibrillation to prevent stroke. The problem with warfarin is, that it requires regular blood test monitoring. There are some dietary interactions like green leafy vegetables that have to be regulated.

Dr. Miller: Antibiotics, if you take antibiotics, seizure drugs.

Dr. DeWitt: Antibiotics, drugs for seizure. There are many interactions and you have to blood test regularly to make sure your dosing is correct. If your dosing is too low then it doesn't protect you, if your dosing is too high, it could cause hemorrhage and this actually leads to a lot of fear sometimes, in not treating patients who are either elderly or might be falling.

Dr. Miller: Or who can't get their testing.

Dr. DeWitt: Who can't get their test done?

Dr. Miller: I know a number of physicians who are uncomfortable treating atrial fibrillation with warfarin. Just because of it narrow window of therapy [inaudible 00:04:00]. That's a big deal, that's a problem. If you have a team of experts, and many times those are pharmacists who take on that monitoring, that's a pretty good way to assure that the patient remains within the therapeutic window. We, at the University of Utah, taken that out of the hands of the physicians if they want us to and monitor that through our [inaudible 00:04:21], and that's have been a very effective way to manage warfarin. Warfarin is not expensive but the monitoring is key. Would you say that's true?

Dr. DeWitt: Absolutely. I tell patients who are on warfarin, the important things is really getting their blood test regularly. There are three new oral agents that have been shown to be effective for treating atrial fibrillation.

Dr. Miller: They are pricey, aren't they?

Dr. DeWitt: They are very pricey because they have a standard dosing and you don't need to do blood test. They have been a bit attractive. The problem is that, a lot of times, the patients are not able to be monitored as well if they do have a stroke, so they may not be a candidate for a thrombolytic agent. In many cases, we just don't feel totally comfortable with them as we are with warfarin in many cases.

Dr. Miller: The problem that I have in practice is, either the cost of neural medication is too much for the older person to afford or the fact that they have to be able to come in for testing and monitoring on a regular basis, whether it's by myself or a team. So there are pluses and minuses with each type of treatment.

Dr. DeWitt: I think the important thing though is that we know that atrial fibrillation is a big factor in stroke. In many cases, it's not just the monitoring but the impression, because the patients are getting older or because they are a little unsteady on their feet, that they shouldn't be treated with anti-coagulation and unfortunately, we are the ones who see those patients come into the hospitals with their big strokes.

Dr. Miller: And aspirin is not enough.

Dr. DeWitt: Aspirin is not enough.

Dr. Miller: Dana, final thoughts?

Dr. DeWitt: Well, I think the important thing is that, with strokes of certain types we suspect clot form the heart and even if we don't pick up atrial fibrillation, I think it's important to monitor the heart and keep looking for it and treat it appropriately.

Announcer: We are your daily does of science, conversation, medicine. This is the Scope, University of Utah Health Scientist Radio.

Dr. Miller: MS or multiple sclerosis. What is it and what can you do about it? We're going to talk about that next on Scope Radio. This is Dr. Tom Miller.

Announcer: Medical news and research from University of Utah physicians and specialists you can use for a happier and healthier life. You're listening to The Scope.

Dr. Miller: I'm here today with Dr. Dana Dewitt who is a professor of neurology and a specialist in multiple sclerosis care. Dana, what is multiple sclerosis? I think we've heard the term but what is it and how does it present and when should somebody be concerned that they might have it?

Dr. Dewitt: Everybody seems to know about the term "multiple sclerosis," but many people really don't understand what it is. It's certainly a neurologic disease. It is a disease that occurs because the immune system is activated and attacks the myelin in the brain and the spinal chord.

Dr. Miller: And we don't know why that occurs, is that true?

Dr. Dewitt: We don't know why that occurs. We know that there's a genetic input. We know that it may have something to do with Vitamin D levels, but we also don't know what actually is the spark that sets it off.

Dr. Miller: So if it's "set off," what does one experience? What are some of the symptoms that might arise?

Dr. Dewitt: There are some classic symptoms with MS. The attack on the nervous system can be on the optic nerve and can cause something that we call "optic neuritis."

Dr. Miller: Which changes vision, I guess?

Dr. Dewitt: Which changes vision. It causes, sometimes, a painful, kind of gritty feeling in the eye and then dimming of vision over time in one eye. The other thing that can happen is that the spinal chord can be attacked and you can end up with numbness or weakness of an arm and a leg or both legs, bladder and bowel dysfunction. Other parts of the brain can be affected that can cause double vision, vertigo, imbalance, those kinds of things.

Dr. Miller: But sometimes it can come on subtly. I mean, I've had a patient in the past who developed multiple sclerosis. His first time was running. He couldn't quite run as far. He had a weakness in one of the legs and then that sort of progressed.

Dr. Dewitt: That's true and there are different forms of MS, the most common type being relapsing/remitting disease. The beginning symptom can sometimes come on over days or a week or two and just get worse and worse. The interesting thing with relapsing/remitting disease is the nervous system has a way of healing itself in MS and so sometimes the symptoms get better and the patient ends up not coming to the attention of a physician early enough, until they've had a few events. At that point, we discover that they've probably had MS for a few years.

Dr. Miller: Now you can have numbness, I guess, on one leg or arm and then maybe weakness on the other and it could alternate back and forth. It could have some sort of strange presentations I think, is that right?

Dr. Dewitt: Exactly and you can have different things occur at different times.

Dr. Miller: Presenting with some of the symptoms that you've just talked about, how do you make the diagnosis and then what do we do about it?

Dr. Dewitt: Probably referral to a neurologist who would listen to your symptoms and do a complete neurologic exam to see what they think is happening. Then one of the ways MS is diagnosed is with an MRI scan and MRI is very, very good at showing the what we call plaque-like lesions that can occur in MS.

Dr. Miller: These little spots on the brain that are tell-tale signs of multiple sclerosis.

Dr. Dewitt: Exactly.

Dr. Miller: So does that mean that we don't have to do this lumbar puncture anymore, to take spinal fluid out and look at it under the microscope?
Most of the time I like doing a lumbar puncture. It tells me how much inflammation there is. It rules out what we call MS mimickers or other unusual things that can look like MS. If an MRI is absolutely classic for MS, occasionally, a lumbar puncture might not be necessary.

Dr. Miller: So you might still need that?

Dr. Dewitt: Yes.

Dr. Miller: Okay. Now, in the not-too-distant past the main treatment was steroids prednisone but there are a lot of new treatments now.

Dr. Dewitt: Most of the initial FDA treatments actually date back to about 1995. So, we've had treatments for quite some time. The major treatments are an interferon or something called glatiramer acetate. Those are all given by injections, which has been a bit problematic for some patients along the way, but they are very effective. They've been around so long we know what to expect and we know how safe they are and they really work. What's been shown in clinical trials is that getting on the drug early and staying on the drug makes an enormous amount of difference.
Now, we do have three new FDA approved oral agents that become options as well. So, the whole armamentarium of treatment for MS now has grown enormously. We still know the important thing is being diagnosed early, getting on treatment, staying on treatment.

Dr. Miller: What looks great in the future? Do you see any treatments on the horizon that you're excited about?

Dr. Dewitt: Well, we're hoping. We're actually doing a clinical trial here now for a new treatment for secondary progressive and what's called primary progressive MS, which are two different presentations for MS different from relapsing/remitting disease. And there really have not been good treatments for those forms of the disease. So we're very excited that we're actually doing this clinical trial here to look at this agent.
I think the other developments are there are a couple of clinical trials looking at potential remyelinating type agents where damage that has occurred in the past can actually be repaired and I think that's what we really want more than anything. The other thing is we're learning more and more with MRI in that we're able to do special MRIs looking at brain volume and we're able to look at certain agents to see if we can prevent degeneration and progression of disease in different ways than what we have available now.

Dr. Miller: You know, it's interesting. With the advent of MRI, which is a magnetic way of looking at the brain. That's allowed this field to progress in its ability to treat people, I think, because now you can actually see inside the brain on these images and look at the plaques and sort of figure out if there are more of them or if they're growing, right? So that's been key.

Dr. Dewitt: Exactly. It's been huge. Part of it is that once a plaque forms it will stay on the MRI as a scar and so we can differentiate between old lesions, new lesions, lesions that enhance with contrast agents. And now we're able to do these brain volume measurements to see how well some of the new medications are working to prevent progression.

Dr. Miller: This allows us a way to really see if the drugs are working and treatment's working. I had heard that stem cell transplant or bone marrow transplant was being tried in the past. Has that been effective at all?

Dr. Dewitt: Yes, there are some places where there are still clinical trials and there are places where bone marrow transplants are being done. There are different kinds of bone marrow transplants. The traditional bone marrow transplant where patients are given high-dose chemotherapy to totally eradicate the bone marrow. The question has always remained in those cases whether the high-dose chemotherapy actually treated the disease effectively enough that it's not really the bone marrow transplant, but those questions are still up in the air.
There are other types of bone marrow transplants now. Something called a mesenchymal transplant or multi-stem, which are these actual intravenous infusions which is a different kind of mode of stem cell transplant which, I think, is the major excitement for the future because I think they're going to turn out to be immune regulators that are far safer than the traditional way of doing a stem cell transplant.

Dr. Miller: Now treating multiple sclerosis is one of your areas of expertise. Would you recommend that people with multiple sclerosis seek a neurologist who have experience with multiple sclerosis?

Dr. Dewitt: I strongly do for a couple of reasons. One is I think making the diagnosis is important and sometimes it can be not so clear. So I think you need a specialist to make the diagnosis. The second thing is now that we have so many treatments, it's important for someone with experience who follows a lot of these patients to be able to choose the proper treatment for you, monitor you to know whether you're responding to that treatment, and then decide whether you need to be changed to something else and follow you over time and just see how you're doing.

Dr. Miller: So it sounds to me like early diagnosis, early treatment, and rigorous follow-up by a specialist who's an expert in multiple sclerosis can make a great difference in the health of these patients.

Dr. Dewitt: Exactly.

Dr. Miller: Any final thoughts?

Dr. Dewitt: We have so many developments for treating MS that it's changed the scope of the disease. It's always hard to give someone the diagnosis at the beginning because people do have a preset idea of what it means and they look down the road and they're very worried about having a chronic condition. I think what I'd like to say is that the treatments that we have available now are really excellent treatments and as long you're followed closely and you know you're on a medication that works, most people with MS live an absolutely normal life.

Announcer: We're your daily dose of science, conversation, medicine. This is The Scope. University of Utah Health Sciences radio.

Dr. Miller: You have had a stroke. How did that happen and how to prevent that from happening again in the future. I am here today with Dr. Dana DeWitt. She is a professor in neurology and a stroke specialist in the University of Utah, the department of neurology. Tell us a little bit about why people have strokes. You have had a stroke, what causes a stroke?

Dr. DeWitt: There are different causes of stroke and it's important that when you have a stroke, to be evaluated by someone who helps determine why it happened. A stroke can occur from a clot coming from the heart, it can occur from a clot coming from one of the arteries in your neck or it can occur because you either have a blood vessel in brain break, or a small blood vessel in the brain close off.

Dr. Miller: But the results, are many times, the same. Is that right?

Dr. DeWitt: Yes.

Dr. Miller: Debilitating problems.

Dr. DeWitt: Debilitating problems, focal deficits, often they don't recover.

Dr. Miller: So Dana, tell me a little bit about the causes behind those embolic, those pieces of tissues that break off or vessels that bruise. What are the main things that cause that to happen? Lifestyle things that might cause another stroke in a patient?

Dr. DeWitt: So, we well know that smoking is one of the major causes of hardening of the arteries and high blood pressure. It's a major risk factor for stroke. We know that high blood pressure is also a big risk factor for stroke. High blood pressure can cause blood vessels in brain to thicken, it can be one of the causes for [inaudible 00:01:35] and can also cause heart disease. And then we know that cardiac conditions, people who have had heart attacks, whose heart doesn't pump normally and then there is the irregular heart beat called atrial fibrillation which carries a high risk of stroke. And that's when a certain part of the heart called the atrium, actually becomes a little stretched and fibrillates and clog can form in the heart.

Dr. Miller: What about age? Is age related to stroke?

Dr. DeWitt: Well, we know well that as people get older, the risk of stroke is greater. We also do see in young people on occasion, sometimes that can be due to hyper-coagulable or clotting [inaudible 00:02:15] problems or something called dissection in blood vessels or tears in blood vessels, but the major strokes occur in older patients

Dr. Miller: Men and women about the same?

Dr. DeWitt: There is a high risk of stroke in men. Then again cause of stroke in women is a little different except if the women was a smoker and had hyper tension and high cholesterol for years, then her risk is the same.

Dr. Miller: So now I am assuming that if you had a stroke, your risk of having another stroke is higher, higher than the average population risk. Is that true?

Dr. DeWitt: It is. Evaluating those patients is why that's so important. There is also something called a TIA, which is really transient ischemic which is a stroke like event, presumed caused by the same thing that causes a stroke but it clears quickly, and patients then are also at risk for stroke within a short period of time. So it's an important thing for a doctor to evaluate you for your blood pressure. If you are a smoker, you need to stop smoking. You need to know what your cholesterol is and treat your cholesterol, and you need to have your heart evaluated to see if you might have atrial fibrillation or some other cardiac risk?

Dr. Miller: It's true. I think that many people that have atrial fibrillation may not know that.

Dr. DeWitt: That's very true. Atrial fibrillation, we are founding more and more about it but it maybe that atrial fibrillation actually isn't seen at the time that the stroke occurs. It may actually be found later and there are now methods, 30 day monitors or what we call loop recorders, which are implantable recorders that watch over a heart for a long period of time to see if atrial fibrillation occurs. Heart ultrasound, called an echo cardiogram can sometimes tell us if the heart is abnormal in a way that can put patient at risk for atrial fibrillation. It's very important because the treatment is...

Dr. Miller: And those work better to reduce the risk of stroke in the future than aspirins?

Dr. DeWitt: Yes. For atrial fibrillation, absolutely. So it is important to know whether that occurs and whether that needs to be treated in that way.

Dr. Miller: let me ask you a couple of other questions. How about the IBTs, is there a risk of stroke [inaudible 00:04:25] which is diabetes?

Dr. DeWitt: There is a risk of stroke with diabetes. Diabetes is part on the blood vessels and it can promote more atherosclerosis. It also causes damage to very small blood vessels which can cause small deep strokes. We know that patients with diabetes sometimes get damage to the arteries and their retina, in their eye, and also in their kidneys. So the same process can happen in the brain and cause strokes.

Dr. Miller: How about just obesity in general. People who are not in very good shape, they are overweight, they are not working out much.

Dr. DeWitt: That carries a risk as well. Metabolic syndrome, we know, is kind of a pre diabetic condition but patients who are obese are also more prone to high blood pressure. They are more prone to high cholesterol and those carry risk of stroke.

Dr. Miller: It sounds to me like high blood pressure, diabetes, possible cardiac functions if your heart is pumping well or not and an abnormal rhythm in the heart could all contribute to second stroke. So, what would you say to the person out there that has had a stroke or had a family member with a stroke? Do you think that many of them know their risk factors or they should really be aggressive in trying to find out if those problems we just mentioned are high risk factors?

Dr. DeWitt: I think that's extremely important. We talk about primary stroke prevention versus secondary stroke prevention. One is, to know your risk factors so that the stroke never happens and you treat them aggressively. The other is, once you have a stroke, know why the stroke occurred so that you can prevent another one by again, controlling those risk factors. And again, those risk factors really are high blood pressure, smoking, high cholesterol, diabetes and then obesity and inactivity carry another risk. Mainly because they promote the other problems.

updated: January 15, 2021
originally published: July 15, 2014