Ask the Mito Doc – February 2023: Cardiac Disease and the Mitochondrial Patient

Ask the Mito Doc February 2023

Cardiac Disease and the Mitochondrial Patient


Clinicians: Hilary Vernon, MD, PhD, Reid Thompson MD, Rebecca McClellan, MGC, CGC. From Johns Hopkins School of Medicine


Watch the video:

Q: How does the heart become scarred? What does this mean in terms of implications for the future and is there anything we can do to stop/slow the scarring? I have LVH and 20% scarring and unsure of what this means. I have recently had an ICD implanted but not sure how this will help?


A: I think it’s depending on what this is you can find scarring, for example, if you have low blood flow like with a myocardial infarction, you will have areas of the tissue that have poor blood flow and those cells die and they’re replaced by fibrosis. We also find it in patients with hypertrophic cardiomyopathy, and presumably there is also some limitation of blood supply to some of the very thick areas of the heart which might result in scar tissue, but also in cases of inflammation of the heart after Myocarditis, for example, or in muscular dystrophy. We think that there is an inflammatory process that happens within the cell, permeability to calcium, and so the exact mechanism, again, probably depends on how the heart is affected by the disorder. But the scar tissue itself can mean that those areas don’t contract well and are more susceptible. There’s quite a lot of work going on at Hopkins to try to map out areas of scar tissue and certain diseases, and then predict who’s at higher risk for Arrhythmia by doing a sort of a virtual electrophysiology study using that information.

Q: What would cause fluid buildup around the heart and lungs? Is that an indication the heart isn’t working?

A: Some kinds of fluid in the lungs, or pulmonary edema, can be caused when the heart is not pumping properly, and fluid backs up in the heart. There are other causes of fluid in the lungs as well, but this should always trigger a thorough heart evaluation.

Q: My heart symptoms cause a lot of anxiety when they come, which I feel like doesn’t help the symptoms. Are there any safer as-needed anxiety meds that are okay for the heart and mito?


A: Many anti-anxiety medications can be used safely in mitochondrial disease. I recommend working with a primary care doctor or psychiatrist who is open to working with a mitochondrial specialist to pick a good medication. I agree with you: reducing anxiety is important!

Q: Why not use mitochondrial dysfunction as a biomarker for Long COVID? Is anyone researching the role of mitochondrial dysfunction in Long COVID? If so, who is it? The NIH is spending $470 million to discover the cause of Long COVID, some of this money should be spent to determine the role of mitochondrial dysfunction.


A: This is something that came out last year in General American College of Cardiology. Some of the information to date with long COVID; There is COVID severity and presumably those with more severe COVID are more at risk for long COVID symptoms, but not necessarily so, and then susceptibility interestingly, is higher in females, those age 30 to 45. That also have maybe something to do with abnormal immune response or autonomic nervous system response, genetics are probably important, underlying health status is also important. But interestingly in this sort of cycle to get set up with the fatigue and decreased exercise capacity and excessive tachycardia, your fast heartbeat. There’s also this orthostatic intolerance, and this inability to stand upright or exercise upright, and they think that a large part of that is the bed rest, the inactivity that’s associated with having COVID and being someone who’s susceptible to the deconditioning and that deconditioning then lowers the blood volume and increases the stroke volume of the heart and so you get this compensatory tachycardia. You never really get out of that deconditioned bed rest sort of state. And anyway, I just point that out, it is something that might be more of a problem for people with some mitochondrial disorders. I think there’s some information that the mitochondria are involved. People are working on that, and that one of the recommendations is to start with more recumbent exercise, instead of immediately trying to exercise standing up and work your way back up to. But certainly, that’s out of my field of expertise. But that’s just something I did find that has come out recently.

Q: My daughter is 18 with Leigh disease & doing relatively well. A few years ago she has slight muscle thickening of ventricles, medication started. She tolerated it for a short period only…she became faint & BP went down. Meds stopped by cardiologist & thankfully follow up echoes showed normal muscle thickness. BP low to normal 100/65 ish. She is T1 insulin dependent diabetic on a pump, with 90% control. My Q is what is the best way to keep her heart healthy & prevent muscle thickening. She cycles 4km daily, uses a rowing machine, eats a very boring, clean, homemade diet, no alcohol, no smoking, avoid excess fatigue, avoids sick people, tries to avoid C19 (1 episode to date), vaccinated…a goodie two shoes life!  She takes usual mito supplements including COQ10 400mg daily, thiamine, l carnitine, BK, Mg, riboflavin, vit B2, B12 etc. She is 54/55kg, 155 cms. Is there anything else that we could do to prevent thickening & keep that heart healthy?

A: It sounds like you daughter is doing well and everything right from a cardiac standpoint: exercise, nutrition, diabetes control, avoiding illness etc. If you aren’t already doing so, I recommend following regularly with a cardiologist who is comfortable with and knowledgeable in mitochondrial diseases.


Q: Do mitochondrial related cardiac issues (such as bundle branch issues, need for pacemaker etc.) tend to show up early in diagnosis/onset of mitochondrial disease? Or, can it occur further down the line? Do mito patients without mito related cardiac issues have to worry about this occurrence for their whole life? Or does the risk of development reduce over time?


A: This is a tricky question. Cardiac issues can come up later in the course in many, but not all, types of primary mitochondrial disorders. If you have not had heart involvement and are comfortable with your cardiologist who has expertise in mitochondrial disease, they may be ok with working out an intermittent schedule for more spread out (every 2-3 years) assessments, but of course, with any symptoms to be seen more frequently.

Q: Leber hereditary optic neuropathy (LHON) is associated with cardiac conduction abnormalities, cardiomyopathies and an increased risk of stroke and cardiovascular mortality. What type and frequency of cardiac screening do you recommend? Since many in the LHON community follow with a neuro-ophthalmologist and their primary care doctor but not a mitochondrial specialist, and the PCP often does not know of the cardiovascular risk with LHON and we frequently hear of patients not able to get a one-time screening ekg or referral to cardiology. Do you have any tips or recommendations on how to make that happen?


A: We do a lot of interdepartmental education that has led to our ophthalmologist sending all patients with LHON to genetics clinic. As part of genetics, we make sure that annual cardiac care is happening. One thing I offer to patients who I only see once (i.e. travel from a distance) is to provide a letter outlining the recommendations for annual cardiac care.

Q: Can POTS / Dysautonomia contribute to a stroke like episode happening? If so, can you please explain.


A: Stroke like events are something that is integral to the brain tissue. However, dysautonomiac events and POTS symptoms can mimic stroke like events and make it very difficult to differentiate one from another. Therefore, in the acute situation, we evaluate for both causes.

Q: What percentage of those with mito are affected by cardiology issues? And are certain types of mito more prone to developing heart issues, if so, which ones (e.g.: KSS; LHON)?



A: Dr. Hilary Vernon: Approximately 20 to 50 % of patients may have cardiac issues.

Q: If the patient community is eager to participate, how can we help increase research on the cardiovascular risk in LHON? In the era of gene therapy trials, there are large studies of geographically diverse but genetically homogenous patients who will be followed for a number of years. Is there a way to get cardiologists involved in these studies to perform some sort of screening evaluation at the outset to the trial so we can use the trials as an opportunity to study the disease as a whole and not just the investigational product?



A: I agree with you, this would be an excellent opportunity for evaluation of natural history data. I am not sure it is systematically collecting this data right now across institutions, but I completely agree this is important!

Q: If you are in a mito crash are you more at risk of having a thrombotic stroke if you have cardiomyopathy.


A: In general, thrombotic (blood clot) strokes are associated with poor heart function or clotting abnormalities or both. Therefore, it depends on the nature of the mitochondrial event (changes in liver function or heart function).

Q: What do you think about Apple watches and other electronics that can take EKGs and other monitoring? Every time I get a monitor for a cardiologist, I don’t have symptoms, but they can be very frequent and scary at other times. I would like doctors to be able to see what’s going on – can they use this data? I was also wondering what symptoms are bad enough to go to the ER. Thanks!



A: Dr. Thompson is just now going to talk about internal loop recorders, these can be implanted and provide several years of monitoring. This does help us identify patients with less frequent events. Symptoms for going to the ER are very, very individual and I hesitate to provide specific parameters. Always go for acute onset chest pain, fainting, shortness of breath, but this is not an exhaustive list. Dr. Reid Thompson: Yes, they’re becoming a very real and potentially useful thing. Everybody’s probably heard about diagnosing a fib on the wearable while I’ve had a lot of patients that have sent me rhythms that we didn’t think we’re in trouble. But recently I did have someone send me a rhythm from their apple watch, and there was atrial fibrillation on it. So, we’re reacting to that as well, so that’s helpful. And the internal loop recorders can be implanted with just a little local anesthesia. And it’s a very simple, outpatient procedure. Those can last up to 5 years. The nice thing about that is you don’t have to be staring into your watch. They’re just recording whatever’s happening to the heart. They’re not doing anything about it, but they’re recording it and sending it through your phone to a central monitoring center that will then alert us, if there is something very important on that. We have been using that data to schedule people for defibrillators, or to really increase our surveillance in other ways or our medications so very important, the new monitoring systems.




Q: Tilt Table test diagnose orthostatic hypotension. Is this common in mito? Are there recommendations to manage this?


A: Yes, Orthostatic Hypotension and POTS symptoms are common in mitochondrial disease. POTS can be very tricky to manage, and there are clinics that are dedicated to this, with treatments ranging from blood pressure management to fluid/salt management.

Q: Are there any heart related medications that Mito patients should use with caution?


A: The medications that we might typically use for one cardiac problem, such as Hypertrophic abnormalities might need to be used with caution. If those patients are also at risk for conduction abnormalities, where slowing the heart may just not be the right thing to do at all. I think again it goes back to what their specific risks are.

Q: How do patients go about finding a qualified cardiologist that’s even heard of Mito before?


A: So just to start out, there are 17 mitochondrial medicine centers that are spread out throughout the United States, and looking at the Mitochondrial Medicine Center website, you can find some of these places. But this really isn’t geographically easy for a lot of people, and so often for families who live in areas, even out of the country, places where they don’t have someone local what’s really important actually is finding someone who’s willing to listen and willing to learn and willing to consult with an expert. I am always willing to talk to anybody who’s calling from any place and say, this is what I would recommend. This is what you should consider, and if someone is willing to listen, I think that’s the most important thing going forward. Dr. Reid Thompson: Some of these diseases are common in childhood, but yet may not be recognized until adulthood. Sometimes you find that expertise in pediatric cardiac centers that have a large heart failure program, and then you know the ones that have typical adult presentation. I again look at places that have an active research program and genetic cardiomyopathies would be a way to find the expertise there. But sometimes you can’t travel to these places. Sometimes I mean, mostly people that are interested in in this sort of thing are very happy and willing to know about a patient, because the patient diseases are rare. Most people are very happy to talk about it. I, when we are faced with someone with a a new disorder that we’ve not encountered ourselves, because it’s so rare. We reach out we find out who’s written about the problem. UMDF Margaret Moore: I also would encourage our families, to make sure that their cardiologist knows about Mito University. We have some really quality products on there that are free for doctors, if a doctor did want to know a little bit more, they could get to it there.