Question: Does heart failure run in families?
Answer: We're finding out more and more everyday about the secrets that have been unlocked as we learned about the human genome. We do -- in fact, we have known for years that heart failure tends to run in families, and, in fact, questions about heart failure in the family is part of the routine history and physical that a cardiologist provides when you go to see them for heart failure. We know that patients who have normal blood vessels, about 25 percent of the heart failure in patients with normal blood vessels, or so-called dilated cardiomyopathy, have a very strong familial background. In some cases, we've even been able to identify the gene that causes that form of heart failure.
Now it's not always true that everyone in the family who was affected is affected in the same way. So sometimes the genetic transmission results in a minimalistic form of heart failure or maybe no obvious heart disease at all, whereas in others it could be a devastating and life-threatening form of heart failure.
The other way that I think is critically important to understand how heart failure can be genetically related is the fact that we know blood vessel disease, or coronary artery disease, has a major genetic component. We know that probably the most important risk factor is a family history of early coronary disease. We also know that two thirds of the people who have heart failure have coronary disease as the cause of the damage to their heart muscle, so that any predisposition to coronary disease -- whether it's because of high cholesterol, or just that every male in your family at a young age becomes affected by the disease -- is apt to make us as cardiologists be concerned that there may be a component that can lead to heart failure.
The final way, that we're just beginning to understand, is that the way we respond to various neural hormones and how they affect the heart is also genetically related, and this affects the way the drugs we use to treat heart failure can affect the outcome of therapy. In fact, we now know that some people respond rather dramatically to some forms of drugs, the beta blockers, whereas other people tend not to respond well at all.
Thanks to the Human Genome Project, we now understand that there are genetic differences in the receptors for the sympathetic hormones that actually count for these discrepancies in the way we respond to drug therapy. So to summarize, if you have a history -- family history -- of heart failure, there are many ways that you can have of predisposition. However, we know that there's many ways to prevent the development of heart failure once we identify people with that predisposition. So this shouldn't scare you away from seeing your cardiologist. If anything, it should bring you closer to your cardiologist so you can develop a plan to prevent you from developing heart failure.