Parent Project Muscular Dystrophy recently hosted the first part of our Cardiac Webinar Seriers with Dr. Linda Cripe (Nationwide Children’s Hospital, Columbus, OH) and Dr. Kan Hor (Cincinnati Children's Hosptial, Cincinnati, OH) to discuss monitoring heart disease in Duchenne and carrier moms/daughters.
There were some great questions asked, but unfortunately we were not able to get to all of them during the webinar. The remaining questions have been addressed below!
Make sure to join us for Cardiac webinar series, Part 2: Interventions in November.
Was the middle one the affected heart with damage?
The three hearts on the slide in question are simply representations of normal, however, scar tissue in the slides with pathology specimens does appear as white. The scar tissue (fibrosis) is located on the outer surface of the heart muscle, known as the sub-epicardial surface in Duchenne. It appears blue on the pathology specimen shown on the right hand side due to the type of stain that is used. As you can see from this slide it can replace a significant amount of heart muscle. It is the scar tissue that keeps the heart from squeezing as well as it should.
When are cardiac MRIs recommended?
Cardiac echocardiograms (or MRIs) and EKGs are recommended at diagnosis and should be repeated at a minimum every other year until age 10. After age 10, the EKG and echo (or MRI) should be repeated at least once yearly unless recommended more frequently by your physician. Cardiac MRI is a much more sensitive tool for evaluating cardiac function than an echocardiogram and if your child is able to cooperate will provide you with more detailed information regarding how well the heart is working. MRI allows us to see if scar tissue (fibrosis) is present. When the child is old enough to lie in the MRI scanner (45-60 minutes) without needing sedation, a cardiac MRI should be done instead of an echocardiogram. This is typically around age 7.
Are there issues with MRI in patients who have had a spinal fusion with rods?
Yes. The spinal rods may cause the MRI pictures to be less clear around the area of the spine but do not really impact our ability to look at the heart by MRI. A cardiac MRI can give relatively good images, even with rods, as long as the patient lies still.
Since MRI cannot be done after spinal surgery, what other tests besides ECG or Echo should take its place?
(see above - "Are there issues with MRI in patients who have had a spinal fusion with rods?")
Second image of cardiac MRI did not show
That image is of a Duchenne boy with depressed heart function.
If there is evidence of scar tissue at an early age, does this mean that the heart function may deteriorate at an earlier age?
That is a great question and at this time we do not truly know the answer. We believe that as scar tissue accumulates in the heart that it will have a direct impact on cardiac function. The presence of a small amount of scar tissue does not necessarily mean that your son’s heart function will deteriorate sooner. If increased scar develops on subsequent cardiac MRI scans, we believe that it will ultimately impact the heart function. We know that all the Duchenne patients have an absolute genetic risk of developing Duchenne-associated cardiomyopathy, with eventual heart dysfunction, but the timing of when cardiac dysfunction occurs is likely complex and most certainly unique to each patient.
Is the recommendation to do a yearly MRI with LGE "common knowledge" in pediatric cardiologists treating kids with Duchenne? Or is this something most of us need to educate our docs about?
Not all adult or pediatric cardiologists perform cardiac MRI at this time in this country and not all hospitals have the equipment to perform the procedure but the technology is quickly spreading.
Is there data re: carrier risk per mutation or region of dystrophin gene where mutation occurs?
That is a good question. At this time we have not been able to definitively establish a connection between the site of the disruption of the dystrophin gene and the timing or risk of cardiomyopathy. It is likely complex and involves modifying genes.
How can I find a quality cardiologist who gets Duchenne carriers?
Adult cardiologists who treat adult heart failure are able to manage cardiac surveillance of carriers. If they are unaware of your risk, or resistant to seeing you every 3-5 years for a visit, EKG and Echo/MRI, it may be best to find a cardiologist who better understands. Several centers (Nationwide Children’s, Columbus and Cincinnati Children’s Hospital) are beginning to have “carrier clinics,” and are doing cardiac surveillance of moms/daughters.
I am a carrier of Duchenne. I had an EKG and Echo. The echo saw some mitral prolapse. Is this just as common for carriers as the cardiomyopathy?
No, the risk for carriers is the same as for the general public. Mitral valve prolapse is a very common problem in the population.
Should carrier girls get a "baseline" MRI before age 16?
The current recommendation is to have baseline testing (EKG, echo/MRI) in the early 20s; sooner if there are symptoms.
Do I understand this correct? The scar tissue seen early on is what can make the heart not function appropriately?
(see above - "If there is evidence of scar tissue at an early age, does this mean that the heart function may deteriorate at an earlier age?")
Would you recommend all carriers come in to Nationwide for evaluation?
Absolutely not. Though it is important to find a cardiologist in your area who understands the issues related to the cardiomyopathy associated with Duchenne. It is important to share with your cardiologist that you are a carrier sibling or a carrier mother of a patient with Duchenne. If they can not help you then they can refer you to centers that can.
What issues have been encountered with insurances in getting Cardiac MRIs?
All insurances are different and you should check with your provider prior to having any testing done. In general, MRIs have been covered under the majority of insurance plans. If it is denied coverage make sure that your insurance provider has received the appropriate request for coverage. The wording of the request should include that this test (MRI) is being done to evaluate cardiac function and to look for the presence of myocardial fibrosis in a patient with a known cardiomyopathy.
What again is used to measure the strain?
That is a great question but very complex to explain. Circumferential strain is one thing that is measured with the MRI. It is a measurement of the motion of the cardiac muscle during the squeeze. Shortening fraction (by echocardiogram) and ejection fraction (by echocardiogram or cardiac MRI) assesses the cardiac function, or squeeze of the heart. Myocardial strain looks at what the way the heart is squeezing and may be a better way at looking at heart muscle function. At this time, however, it is a research tool and is not yet used clinically. It will likely be used in combination with other findings, such as LGE/Scar, in order to to better define the stage of cardiomyopathy and/or heart failure.
There is no carrier care around here. My cardio had no clue. And nothing for my carrier daughter.
I would contact your neuromuscular clinic and speak with the cardiologist on their team. The cardiologist on the neuromuscular team should be able to speak to you about your daughter, and should be able to recommend an adult cardiologist in your area that could provide care for you and, when your daughter is older, for your daughter.
Kathi Kinnett, Director of Clinical Care
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