Causes, Risks, and Prevention of Cryptogenic Stroke [Interview][Transcript]

Dr_John_Rogers_Crytogenic_StrokeGuest: Dr. John Rogers
Presenter: Neal Howard
Guest Bio: Dr. John Rogers is Associate Chief of Cardiology and Director, Cardiac Pacing and Tachyarrhythmia Device Therapy at Scripps Clinic Medical Group in La Jolla, California. He is skilled in syncope, electrophysiology and implantation of pacemakers and internal cardiac defibrillators and CRT devices.

Segment overview: Dr. John Rogers, MD, FACC, Associate Chief of Cardiology and Director, Cardiac Pacing and Tachyarrhythmia Device Therapy at Scripps Clinic Medical Group in La Jolla, California, discusses cryptogenic strokes.

Health Professional Radio – Cryptogenic Stroke

Neal Howard: Hello and welcome to Health Professional Radio. I’m your host Neal Howard, glad that you could join us today. Our guest in studio is Dr. John Rogers, he is the Associate Chief of Cardiology and Director of Cardiac Pacing at Scripps Medical Clinic in La Jolla, California and he’s here today to talk with us about cryptogenic stroke and the risks of stroke, how we can prevent stroke, what causes stroke, and a lot more. Welcome to Health Professional Radio Dr. Rogers.

Dr. John Rogers: Thank you very much Neal, thanks for having me on.

N: Have you always been interested in cardiology? Did you start out as a heart specialist or is this something that evolved over time?

R: You know it’s interesting Neal, I actually went to medical school with the plans of being a pediatrician and as I learned more of the different areas of medicine, settled in cardiology because it just became such a fascinating subject to me. Fascinating that there were so many new and exciting therapies and technologies for doctors to help patients with all different types of heart problems and I’ve never been sorry that that’s the field I chose.

N: Is a stroke the result of the heart problem or is a brain problem or is it a combination of the two?

R: Well it can be either actually Neal. Stroke is actually a problem primarily with the brain but the source of the stroke can be from a heart problem, it can be from a vascular or a blood vessel problem, or it could be from a problem with the brain itself. So all those are possible sources of stroke. There are 2 basic types of categories of stroke, one is ‘Ischemic’ which means something or somehow a blood vessel became blocked which caused lack of blood flow or damage or to the heart, much like a heart attack happens when a blood vessel to the heart becomes blocked. The ischemic strokes are responsible for most strokes. The other maybe 15% of strokes come from actually problems where the blood vessels rupture or bleed into the brain and our called ‘Hemorrhagic Strokes.’

N: Is there something that we are doing or cannot do to prevent that blockage?

R: Certainly there are risk factors that we have that can lead to blocked up arteries that can affect the arteries. All aspects of our body is the heart, are purple blood vessels and the blood vessels go to our brain, risks such as high blood pressure, diabetes, high cholesterol, smoking, sedentary lifestyle, being overweight, other vascular diseases that we’re aware of that we may be able to get on top of and treat and then there are some heart rhythm problems namely ‘Atrial Fibrillation’ that can cause stroke, that if we know that we have that and we can address that heart rhythm problem appropriately, we can prevent stroke. So there are a lot of different causes that may lead to an ischemic stroke.

N: Now within this ischemic stroke category, are there different types of strokes that are ischemic?

R: There are. There are the types of stroke that come from a blocked up blood vessel, they are the type that come from an embolism or a blood clot coming from somewhere else such as the heart or of one of the blood vessels leading to the brain. There are other smaller tiny blood vessels that can include their cause, very small areas of the brain to become damaged overtime and enough of that will cause significant damage to the brain tissue. Well the term, ‘Cryptogenic’ basically means that it’s a hidden source, we don’t know where that came from. So most of the patients that come in for a stroke workup, they all go through a fairly exhaustive workup to find out why they’ve had a stroke. When all that workup is completed and we still have not found the cause of stroke, then we deem that stroke cryptogenic or a stroke of unknown source. And that usually accounts for unfortunately between, 20 and 30% of all strokes.

N: Now, are these strokes and their causes and some of the ways that patients present, are these stored in one central place where cardiologists and other researchers can kind of collaborate?

R: Well there was a landmark paper, a very large publication called ‘Crystal AF’ that was published in 2014 in the New England Journal of Medicine. That was the first large randomized controlled trial that show doctors that, even after an exhaustive workup, there are still a significant number of patients that we don’t know why they’ve had a stroke and thus those cryptogenic stroke patients. And that perhaps looking harder to find if they have a heart rhythm problem or looking for a longer periods of time they help us to understand, is this possibly coming from a heart rhythm problem called atrial fibrillation. That large study helped doctors to realize that we need to make sure that the patients go through that extensive workup. But most of the information that you’re asking about, it resides in the electronic medical record of the health care system that the patient is in. That study was key in letting us know what really need to be done to rule out causes of stroke and they continue to look for causes of a stroke, so we don’t have to call cryptogenic even more, we can find out why that patient had a stroke for us to prevent further stroke.

N: Now where can our listeners in wrapping up go and get more information about your group and strokes in general?

R: Well I think the American Stroke Association which is a branch off of the American Heart Association has the most up to day, the most valuable information. The American Heart Association itself, the American Association of Neurology, all has really critical information for patients to go to, to look out what is a stroke, how do you know if you’re having a stroke, what risk factors might I have that I can work on to help prevent myself from having a stroke?

N: Well I’m glad that you decided to talk with us today doctor.

R: Thank you, my pleasure.

N: You’ve been listening to Health Professional Radio, I’m your host Neal Howard, in studio with Dr. John Rogers. Transcripts and audio of this program are available at and also and you can subscribe to this podcast on iTunes.

Liked it? Take a second to support healthprofessionalradio on Patreon!