"HANG ON. HELP IS ON THE WAY. " >Page 1, 2, 3, 4
Coming advances in heart failure
Click here for a review of heart failure.
Biventricular
pacing
Many patients with heart failure have abnormalities in their cardiac electrical
system that causes their already weak heart muscle to beat in a discoordinated
fashion. This inefficient muscle contraction wastes the heart's precious
energy, and causes the heart failure to worsen.
New investigational pacemakers - biventricular pacemakers - stimulate both the left and right ventricle (instead of just the right ventricle,) to allow the heart to beat in a more coordinated, energy-efficient, and effective manner. Data presented at the ACC meeting last week, as well as data published in last week’s New England Journal of Medicine, have documented the effectiveness of biventricular pacing. In patients with heart failure who had no “traditional” reason for receiving pacemakers, both the quality of life measures and more objective measures of cardiac function significantly improved with biventricular pacing. For a substantial proportion of patients with heart failure, these devices appear to offer major clinical improvement.
At least two U.S. companies (Guidant and Medtronic) have applied to the FDA for permission to market biventricular pacemakers for the treatment of heart failure. These devices may come into widespread use late this year or early next year.
Myogenesis
Early clinical trials are taking place using myogenesis – stimulating the
growth of new heart muscle. Most
forms of heart failure are associated with the conversion of normal heart muscle
into scar tissue. Work has been
underway in animal models to inject primitive heart muscle cells (myoblasts)
into damaged heart muscle, in order to stimulate growth of new heart muscle in
damaged areas. This work has shown
immense promise.
Very early clinical trials in humans are now underway. While no results are available yet from these studies, myogenesis offers a completely new avenue of approach for the treatment of severe heart failure. And based on the results of animal trials, the question is not so much whether it will work in humans, but which of the many possible techniques for stimulating myogenesis will be the most effective. It is likely to be several years before myogenesis becomes routine for patients with heart failure.
Artificial
hearts
The long quest for a permanently implantable artificial heart finally appears to
be nearing fruition. While it has
been a long time coming, the artificial heart has come a long way since the
Jarvik-7 was implanted in Barney Clark 20 years ago.
The LionHeart, manufactured by Arrow International, Inc., is a permanently implantable cardiac assist device (a device that supports but does not replace the heart’s pumping action.) This device is now undergoing clinical trials. The AbioCor, manufactured by Abiomed, on the other hand, is a permanent, totally artificial heart that is ready for clinical trials. Other companies are fully engaged in developing their versions of cardiology’s holy grail.
It seems entirely likely that, during this decade, a fully implantable, permanent artificial heart will finally come into routine clinical use. Obviously, such a feat will revolutionize the outlook for the tens of thousands of patients that die each year from end-stage heart failure.
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