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Cardiogenetics: The Importance of Genetic Testing and Counseling

Susan O'Donoghue, MD, discusses the burgeoning field of cardiogenetics, which can help identify various certain inherited cardiovascular disorders, particularly those that are based in the heart's electrical system. Potential candidates include individuals who have fainted due to physical exertion or who have a family history of unexpected cardiac arrest and/or death at young ages.

Dr. O'Donoghue also explains the importance of genetic counseling pre- and post-screening and guidance on when a molecular autopsy might be in order.
Cardiogenetics: The Importance of Genetic Testing and Counseling
Featured Speaker:
Susan O’Donoghue, MD
Susan O'Donoghue, MD, is a board-certified cardiac electrophysiologist at MedStar Heart & Vascular Institute at MedStar Washington Hospital Center. She previously served as Associate Director of the Cardiac Arrhythmia Center and Director of the Combined Cardiac Electrophysiology Fellowship Program at MedStar Georgetown University Hospital/MedStar Washington Hospital Center. She is presently Director of Cardiogenetic Services at MedStar Washington Hospital Center, a new program for the diagnosis and treatment of inherited cardiac disorders, which she developed. Dr. O'Donoghue has been providing care for more than 25 years.

Learn more about Susan O'Donoghue, MD

Melanie Cole (Host): Imagine a world where genes not only tell the story of a person's future health but allow physicians to intervene early and prevent future health problems. The fast-growing field of Cardiogenetics allows for improved screening and early treatment of certain inherited cardiovascular disorders. My guest today is Dr. Susan O'Donoghue. She is a Cardiac Electrophysiologist with MedStar Heart and Vascular Institute at MedStar Washington Hospital Center. Welcome to the show, Dr. O'Donoghue. First, let's -- explain what this growing field of Cardiogenetics is.

Dr. Susan O'Donoghue (Guest): Certainly. Cardiogenetics is the study of a patient's inherited tendencies for heart problems. We're all aware that some families have an elevated cholesterol and they have a likelihood of developing coronary artery disease and that's a general tendency, but in addition to that, there are very specific genetic disorders which can be inherited as -- what's called an autosomal dominant -- meaning the individual has a 50% chance of carrying the disorder. Some of them are associated with very specific heart rhythm problems or problems with the heart muscle, and there's much more that can be done nowadays to both screen for and treat these disorders.

Melanie: So tell us about some of the inherited disorders that are associated with heart rhythm problems. What are some of the conditions?

Dr. O’Donoghue: Well, some of the conditions include what's called the Long QT Syndrome. The QT interval is an EKG measurement that's a reflection of the heart's electrical recovery after each heartbeat. Probably at least one in 2000 people carry a gene mutation that affects how the heart electrically recovers, and these individuals can be at risk for unexpected serious, even life-threatening heart rhythm problems. There are many others including disorders such as Hypertrophic Cardiomyopathy, which is probably at least everyone in 500 people and in this disorder, the heart muscle is anatomically abnormal. It is abnormally thickened. In addition, the heart's electrical system can be affected, so again these individuals can have a variety of heart rhythm problems, some of them potentially quite serious. And there are quite a number of other disorders that affect, specifically, the heart's electrical system.

Melanie: So then when would this take place -- when would you want to find out, and with who -- about whether somebody is at risk for these?

Dr. O’Donoghue: The red flag for recognizing an individual who might carry one of these inherited disorders include things such as fainting during exercise, or of course, anyone who has experienced a cardiac arrest and been successfully resuscitated, particularly below age 40, when the more common things such as coronary disease are much less common. In addition, if an individual has a family history of multiple relatives having died unexpectedly at a young age unexpectedly, again that would be a situation where we would want to evaluate that individual and that family and see if we can identify the problem and prevent future catastrophic illnesses or sudden deaths.

Melanie: We have been hearing in the media, and there's even some legislation put forth about testing kids in sports for sudden cardiac death, which can occur at any age, but specifically had been seen in athletes and the American College of Sports Medicine has been on this case. What do you say about this particular condition? What do you think about it?

Dr. O’Donoghue: That topic, as to whether children should be screened for participation in sports and how they should be screened, is actually very controversial. It's a very complex subject, and there are cardiology associations in both Europe and the United States, who have weighed in on this topic and there are some differences between the recommendations in Europe and here in the United States. On the plus side, of course, if you can identify an individual who may be at risk, that's extremely important and can be life-saving. On the downside, is mass screening and EKGs for everyone indiscriminately also ends up identifying patients -- individuals who don't really have a problem, but their EKG is just a little bit outside the norm. The concern is that a lot of individuals can be precluded from participating even though there's nothing really wrong. And then of course, as with everything, there's the cost-benefit ratio. How much does it cost to identify one individual and is this the way our resources should be spent? It's actually a very interesting and controversial topic. I wouldn’t say it's totally settled at this point. Clearly, anyone who's going to participate in sports should be examined by their doctor. The doctor should be asking questions about family history and about symptoms. That, I think, there's universal agreement on.

Melanie: So tell us about some of the Cardiogenetics services at Medstar Washington Hospital Center that you provide including genetic testing and counseling after the testing.

Dr. O’Donoghue: Absolutely. The field of genetic testing is really in its early stages, but will clearly become much more important as the years go by. It's possible now with a sample of blood or saliva to test for these specific genetic disorders. Part of that testing -- part of our responsibility when we do that testing -- is to order the tests responsibly and properly to know what questions to ask and what abnormalities to look for. Very importantly, a part of any Cardiogenetics service has to be genetic counseling before the test to know what the implications are, and also to help the patient and their family interpret the results because the results can be quite complex and not necessarily a simple "yes, or no." One of the services we offer is genetic counseling, which as they say should be mandated anytime genetic testing is going to be carried out. In addition, of course, if we identify a disorder, we have all modes of treatment available from medications, to device implantation, to surgery, whatever might be required.

Melanie: So if somebody is on the fence as it were about genetic testing -- and we've all heard about it with the BRCA gene and all of this -- but this is relatively new for listeners to hear about. When would you suggest that people really consider getting this genetic test, or even coming in for counseling for it?

Dr. O’Donoghue: Individuals who have had either been identified with one of those disorders, or individuals whose family members have been identified, or who have a family history of sudden death, or congestive heart failure in young family members. Those individuals would benefit from coming in, giving us their history, letting us review the available records, and then, of course discussing whether this is a situation where genetic testing might be helpful. Genetic testing is not something that we do just to see if someone might develop coronary disease because they have an elevated cholesterol. That's an entirely different evaluation. Genetic testing is not part of that evaluation. It's really for patients with suspicion or known family history of sudden death, or heart failure at a young age, of fainting spells at a young age.

Melanie: So wrap it up for us, Dr. O'Donoghue, with your best advice about what you want people to know about this burgeoning field of Cardiogenetics?

Dr. O’Donoghue: What I would like people to know is that we can empower them, that knowledge is power, and that if there is a family history that is suspicious, or in fact, if an individual in their family dies suddenly and unexpectedly, they should request a molecular autopsy in addition to a traditional autopsy. Blood should be saved to allow for genetic testing so that other individuals don't need to fear and don't need to be at risk. It's possible after an unexpected sudden death to identify the problem and give very specific treatment and to give some reassurance to the rest of the family. The concept of molecular autopsy is something people are not familiar with, and people need to be familiar with.

Melanie: And tell us about your team at MedStar Washington Hospital Center.

Dr. O’Donoghue: Well, MedStar Washington Hospital Center, of course, has been the leader in Cardiology in the region for many, many years. I've been here for 25 years as a Cardiac Electrophysiologist and have long wanted to develop a Cardiogenetics program, which we have now got in place and, of course, when patients come in, and we can identify their problem, we can hook them up with experts in every aspect of cardiac care, be it valve problems, be it heart rhythm problems, the cardiac imaging here, whatever they might need, we take a team approach. I have a wonderful genetic counselor, and we have all my colleges and all of their various subspecialties of cardiology so we can treat the entire family. For the youngest members of the family, we also work closely with colleagues at Children's Hospital, which is of course right next door to us. The aim is to take care of the entire family.

Melanie: Thank you, so much for being with us today. It's really great information. You're listening to Medical Intel with MedStar Washington Hospital Center. And for more information you can go to, that's This is Melanie Cole, thanks so much for listening.